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Crops, Browse and

Pollinators in Africa

An Initial Stock-taking

produced by the

African Pollinators Initiative

This publication has been supported by the FAO Netherlands Partnership

Programme and the Government of Norway

Food and Agriculture Organization of the United Nations

2007

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page ii

ROPS, BROWSE AND POLLINATORS IN AFRICA:

page iii

N INITIAL STOCK-TAKING

FIRST PUBLISHED IN 2003 BY THE AFRICAN POLLINATOR INITIATIVE SECRETARIAT

ENVIRONMENT LIAISON CENTRE INTERNATIONAL

P.O. BOX 72461, NAIROBI, KENYA

TEL: +254 20 576119

FAX: +254 20 576125

PLANT PROTECTION RESEARCH INSTITUTE

AGRICULTURAL RESEARCH COUNCIL

PRIVATE BAG X134

PRETORIA, 0001, SOUTH AFRICA

TEL: +27 12 323-8540

FAX: +27 12 325-6998

EMAIL: [email protected]

NATIONAL MUSEUMS OF KENYA

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P.O. BOX 40658, NAIROBI, KENYA

TEL: +254 20 374-2445

FAX: +254 20 374-4833

EMAIL: [email protected]

DEPARTMENT OF ZOOLOGY

UNIVERSITY OF CAPE COAST

CAPE COAST, GHANA

TEL: +233 42 31191

FAX: +233 42 32446

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INTERNATIONAL CENTRE OF INSECT PHYSIOLOGY AND ECOLOGY

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EMAIL: [email protected]

INSECT COMMITTEE OF NATURE KENYA

The East Africa Natural History Society

P.O.Box 44486 GPO 00100

NAIROBI, Kenya

Email: [email protected]

Republished in 2007, with assistance from FAO and Nature Kenya

page iv

ROPS, BROWSE AND POLLINATORS IN AFRICA:

List of Contributors

Connal Eardley: Agricultural Research Council, Plant Protection Research Institute (ARC-PPRI), Private

Bag X134, Pretoria, Queenswood, 0121, South Africa, Fax (+27 12) 304 9578 / 325 6998. EMAIL: EardleyC@

arc.agric.za

Barbara Gemmill-Herren: Food and Agriculture Organization. Vialle delle termedi caracalla, Roma, 0153,

Itary. Tel: +390657056835. barbara.Herr[email protected]

Mary Gikungu, Invertebrate Zoology Department, National Museums of Kenya (NMK), P.O. Box 40658,

Nairobi, Kenya. Tel/Fax (254 2) 3742 445 / 3744 833., mgikungu@yahoo.com

Rachel Kagoiya: Invertebrate Zoology Department, National Museums of Kenya (NMK), P.O. Box 40658,

Nairobi, Kenya. Tel/Fax (254 2) 3742 445 / 3744 833. [email protected]

Wanja Kinuthia: Invertebrate Zoology Department, National Museums of Kenya (NMK), P.O. Box 40658,

Nairobi, Kenya. Tel/Fax (254 2) 3742 445 / 3744 833. [email protected]

Peter Kwapong: Department of Entomology and Wildlife, University of Cape Coast, Cape Coast, Ghana. Tel/

Fax +233 42 31191/32095 pkw[email protected]

Dino Martins: Insect Committee of Nature Kenya,The East Africa Natural History Society

P.O.Box 44486 GPO 00100, NAIROBI, Kenya. [email protected]vard.edu

Grace Njoroge: Jomo Kenyatta University of Agricultural Technology, Nairobi, Kenya,

[email protected]

Laban Njoroge: Invertebrate Zoology Department, National Museums of Kenya (NMK), P.O. Box 40658,

Nairobi, Kenya. Tel/Fax (254 2) 3742 445 / 3744 833. [email protected]

Geoff Tribe: ARC-PPRI, Private Bag x5017, Stellenbosch, 7559, South Africa Tel/Fax (+27 21) 8874690 / 8833285,

[email protected]

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N INITIAL STOCK-TAKING

Table of Contents

List of Contributors iv

List of Figures and Titles vi

Frontpiece: Pollinators of Selected Crops in Africa vii

Preface viii

Summary of Lessons Learned ix

Introduction 1

Identifying the State of Knowledge 2

Farmers’ Knowledge in Kenya 2

Rachel Kagoiya

Farmers’ and Extensionists Knowledge in Ghana 2

Peter Kwapong

Research and Civil Society Organisations: Knowledge of Pollination 3

Dino Martins

In the Literature 4

Barbara Gemmill -Herren

Initial Assessments and Lessons Learned 11

Methods and Approaches 11

Fruit Crops 14

Deciduous fruit in South Africa: 14

Geoff Tribe

Watermelon in Kenya 20

Grace Njoroge, Laban Njoroge, and Barbara Gemmill

Mango in Ghana 22

Peter Kwapong and Mary Botchey

Papaya in Kenya 24

Dino Martins

Avocado in Kenya 27

Wanja Kinuthia and Laban Njoroge

NUT CROPS 29

Cashew in Ghana 29

Peter Kwapong

OIL CROPS 31

Coconut in Ghana 31

Peter Kwapong

Groundut in Ghana 33

Peter Kwapong and Wisdom Hordzi

Oil Palm in Ghana 35

Peter Kwapong and Benjamin Mensah

BROWSE 37

Acacia Pods in Kenya 37

Dino Martins

Indigofera in Kenya 43

Barbara Gemmill-Herren

BEVERAGE AND STIMULANT CROPS 45

Coffee in Kenya 45

Wanja Kinuthia, Barbara Gemmill-Herren and Laban Njoroge

Summary and Conclusion 51

Acknowledgements 53

Picture Credits 53

References Cited 54

page vi

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Frontpiece: Pollinators of Selected Crops in Africa vii

Figure 1: Subﬁelds covered in African pollination literature 4

Figure 2: Types of research covered in African pollination literature 4

Figure 3: Interview bouquets 11

Figure 4: Peach trees in South Africa 14

Figure 5: Non-Apis visitation patterns to watermelon, Kenya 20

Figure 6: Male ﬂowers, Watermelon 20

Figure 7: Inﬂoresence and immature fruits of mangoes 22

Figure 8: Male ﬂower of Papaya 24

Figure 9: Female ﬂower of Papaya 24

Figure 10: Herse convolvuli (with tongue extended)- one of the

hawkmoths pollinating Papaya 24

Figure 11. Cashew ﬂowers and young fruit 29

Figure 12. Female Coconut Flowers 31

Figure 13. Groundnut in ﬂower with ﬂower beetle feeding on petals 33

Figure 14. Female inﬂorescence, Oil Palm 35

Figure 15. Male inﬂorescence, Oil Palm 35

Figure 16. Percentage types of ﬂoral visitors to Acacia tortilis, Kerio Valley 37

Figure 17. Acacia ﬂowers 37

Figure 18. Percentage types of ﬂoral visitors to Acacia tortilis,

close to bomas 38

Figure 19. Percentage types of ﬂoral visitors to Acacia tortilis,

natural vegetation site 38

Figure 20. Indigofera blossoms 43

Figure 21. Stingless bee nest entry 43

Figure 22. Honeybees on Coffee 46

Figure 23. Bagged Coffee inﬂorescences 46

Figure 24. Coffee plantation and riparian forest, with wild honeybee hives 46

Figure 25. Percentage types of ﬂoral visitors to coffee 47

Figure 26. Average number of ﬂowers visited by taxa 47

Table 1. Commodities dependent on pollination in Africa 6

Table 2. Number of Blossums visited by a single honeybee in ﬁve minutes 15

Table 3. Floral visitor to orchard tree species at Bien Donne 16

Table 4. Floral visitors to Watermelon, Kenya 21

Table 5. Floral visitors to Mango, Ghana 23

Table 6. Floral visitors to Papaya, Kenya 25

Table 7. Floral visitors to Avocado in Gachie village,

Kiambu District, Kenya 28

Table 8. Floral visitors to Cashew, Ghana 30

Table 9. Floral visitors to Coconut , Ghana 32

Table 10. Floral visitors to Groundnut (peanut), Ghana 34

Table 11. Floral visitors to Oil Palm, Ghana 36

Table 12. Ranking of effectiveness- Acacia visitors 38

Table.13. Behaviour of ﬂoral visitors on Acacia tortilis blossoms 40

Table 14. Major bee visitors to

Indigofera spp. 44

Table 15. Other bees visiting coffee ﬂowers 48

Table 16. Insects besides bees visiting coffee 49

List of Tables and Figures

page vii

N INITIAL STOCK-TAKING

Frontpiece:

* note that in none of the systems studied did vertebrate pollinators play a documented role.

page viii

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Preface

When the Fifth Conference of the Parties to the Convention Biological Diversity established an International

Initiative for the Conservation and Sustainable Use of Pollinators (also known as the International Pollinators

Initiative-IPI) in 2000 (COP decision V/5, section II), FAO was requested to facilitate and co-ordinate the

Initiative in close co-operation with other relevant organisations. A Plan of Action for the IPI was adopted

at COP 6 (decision VI/5), providing an overall structure to the initiative, with four elements of assessment,

adaptive management, capacity building and mainstreaming.

FAO, through the FAO/Netherlands Partnership Programme, supported the initial establishment of a regional

African Pollinator Initiative, the development and publication of its Plan of Action in 2003, and an initial

stocktaking of pollinator-dependent crops and browse plants in Africa. The stocktaking document has only

been available in electronic form; support from the Government of Norway has permitted its publication in

2007.

We hope that the information contained in this stocktaking document will inspire others to make assessments

of pollination services in their countries or regions as appropriate. We would encourage those that do so to

share these with FAO for wider dissemination, through the following address: [email protected].

Linda Collette

FAO Responsible Ofﬁcer for the IPI

Rome, Italy

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N INITIAL STOCK-TAKING

Lessons learned . . .

in South African pollination assessments

Honeybees were essential as pollinators of the ﬁve orchard crops; some exotic weed species

were beneﬁcial to indigenous pollinators especially honeybees in supplying nectar and pollen;

but the greatest variety and numbers of pollinator species were present on indigenous ﬂower-

ing plants.

Lessons learned . . .

in Ghanian pollination assessments

In Ghana, farmers would appreciate more extension information on pollination services.

In a rapid assessment of crop pollination, it was found that even though honeybees visit man-

gos early in the morning, the main pollinators of mango seem to be various ﬂy species, which

remain on the little ﬂowers most of the day. Cashew had wider species diversity of pollinators,

while for oil palm beetles are the main pollinators. The main pollinator of Coconut are sting-

less bees, some wasps and other small bees. Flower visitors to groundut were noted, including

halictid bees

Lessons learned . . .

in Kenyan pollination assessments

In Kenya, it was found that farmers’ knowledge of pollination is limited: many farmers lump

pollinators together with insect pests, and do not explicitly manage to conserve them, although

pollinators may contribute substantially to yields at no cost to the farmer. Most researchers

working on projects related to pollination are addresssing bee-keeping, or bee taxonomy. Other

aspects of pollination services are not being addressed.

In a rapid assessment of crop pollination needs, it was noted that while bees that nest in cavi-

ties are often considered the most manageable, non-honeybee pollinators of watermelon made

use of on-farm conditions to nest in the ﬁeld soil. Conditions promoting them to nest could be

studied and utilised to increase watermelon pollination. Papaya needs pollinators able to ﬂy long

distances between scattered trees with separate male and female blossoms. Recommendations

for conserving the hawkmoths that pollinate papaya effectively are needed. Although avocado

is an exotic tropical fruit to Kenya, its reproduction has adapted well to a diverse range of local

pollinators. Coffee producers do not seem to be aware that pollination can increase yields, and

are removing habitat on farm for wild bee populations.

Browse pollinators are important, but often overlooked. Most of the important Acacia pollina-

tors nest in dead wood, making room for low-tech pollination management in that farmers that

depend on this resource should not denude the areas of dead wood. Many crop and browse

pollinator species could only be identiﬁed to genera. This severely limits our ability to assess

whether they are shared amongst several crops, or speciﬁc to individual crops.

Summary of Lessons Learned

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N INITIAL STOCK-TAKING

Introduction

Pollination is an ecosystem service that is key to food security. Pollinators are essential for many fruit

and vegetable crops. In agriculture, especially amongst pollen-limited crops, promoting pollination

services is a means of increasing productivity without resorting to expensive agricultural inputs of

pesticides or herbicides. Indeed, pollination services are most likely underpinning productivity in

many crops without farmers even recognising it, so long as habitat and alternative pollinator forage

are readily available as they often are in smallholder farming systems.

By developing larger and larger ﬁelds and landscapes for agriculture, we remove the habitat that pol-

linators may need. Increasing dependence on pesticides for pest control is also highly detrimental to

beneﬁcial insects such as pollinators, unless planned and undertken with extreme care. Pollination

is a service nature provides that we have tended to take for granted, and that we often do little to

encourage until we start to lose it. As wild ecosystems are increasingly converted to more human-

dominated uses to meet the compelling demands of food security, it is critical for us to understand

what pollination services are most important for food security, and how we can preserve pollinator

services in sustainable farming systems.

A crop’s pollinator dependence differs between species, including between crops and crop varieties.

Some plants must be cross-pollinated, others do not need pollinators but produce better fruit and

seed if pollinated, and a number are strictly self-pollinated. Further, plants differ in their pollina-

tor-type requirements; some require speciﬁc pollinators while others are pollinated by a variety of

visitors, and many are wind pollinated. Effective pollinators of the same crop may vary from one site

to another. Speciﬁc knowledge on pollinator dependence and types is important for agriculture and

biodiversity (including agro-biodiversity) conservation. With this objective, researchers in Ghana,

Kenya and South Africa were supported by the United Nations Food and Agriculture Organisation

in 2003 to undertake an initial assessment of pollination needs and gaps in knowledge of the key

pollinators of a few crops, and indigenous plants used by people or livestock (Acacia and Indigofera),

in their respective countries. This assessment included both literature reviews and ﬁeld observation;

and is on-going. The long-term aim of assessments is to identify the key pollinators and prioritize

vulnerable pollination systems, in particular those in which explicit pollinator management practices

can have the most beneﬁcial impacts. As the African Pollinator Initiative plan of action has speciﬁed,

methodologies were used that must give results that are scientiﬁcally justiﬁable, and comparable.

page 2

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Identifying the State of Knowledge:

Farmer’s Knowledge in Kenya

Rachel Kagoiya

Farmers around the world understand better than most of the public that good environmental health

is fundamental to their sustainable existence, but often in a holistic way that may not include an

in-depth understanding of the role of pollination. The importance of ecosystem services will not

be ‘mainstreamed’ or become considered as a part of accepted farming practice unless the farming

community understands explicitly what it is and how it works. A good example of this is pollination

services. Globally, within the United Nations Convention on Biological Diversity, and regionally,

within the African Pollinator Initiative, the contribution of pollinators for increasing genetic diversity,

adaptation, seed set or crop production and crop quality, and natural regeneration of wild species has

been recognised, and the need to conserve pollinators has been stressed. Yet the public’s, including

farmers’, knowledge of the role of pollinators, remains poor. Surveys carried out amongst farmers

in central Kenya highlighted the fact that many farmers lump pollinators together with insect pests,

and do not explicitly manage to conserve them, although pollinators may substantially contribute

to yields at no direct cost to the farmer. Ecosystem services such as pollination and soil biodiver-

sity are aspects of the environment that relate closely to human livelihoods, and may convince the

public that biodiversity is not only wild animals that may damage their crops, but also creatures that

live on their farms and help to sustain crop production. Further public awareness programmes on

ecosystem services are merited.

Farmers’ and Agricultural Extension Agents’ Knowledge in Ghana

Peter Kwapong

In Ghana, interviews with farmers, extension agents, and agricultural lecturers indicated that all of

these groups are aware of pollination and pollinators, to varying degrees. All respondents agreed

that pollination is important in agriculture and that absence of pollination will not result in fruit and

seed formation. Only a few believed that plants can reproduce vegetatively. Respondents (83%)

think that crop yield increases when ﬂowers are sufﬁciently pollinated. But most people sampled

(93%) think that humans have a major role to play in ensuring adequate pollination and only a few

understood that it is a natural ecosystem service that should be allowed to go on unaided.

Farmers had limited knowledge on pollination and pollinators. With respect to pollinators, most of

the farmers said they left any insect found on plants during ﬂowering not because they really un-

derstand their role but they think bees provide honey for medicinal purposes and also form part of

God’s creation and must be left alone. A few farmers however claim that they sprayed bees found on

their crops for fear of attack. In order to promote pollination services some of the respondents sug-

gested natural habitat should not be destroyed through bush burning, deforestation and insecticide

spraying. Some people think that pollinator friendly type of farming should be adopted to protect

pollinators from physical, chemical and biological enemies.

Extension agents had more knowledge on pollination: for example, 75% of Agricultural agents

thought that pollinators need to be protected from sprays compared to 31% of farmers who think

the same.

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N INITIAL STOCK-TAKING

But such information was not being disseminated: farmers felt that the Ministry of Agriculture had

not been proactive in promoting the awareness and occurence of pollination and the need to protect

the service. In terms of help to farmers, 49% of the agents think that they have created the pollinator

awareness to farmers. From the farmers’ point of view, 73.7% said the have had no help from the

Ministry of Agriculture on the subject whilst 26.3 said they have received such help (awarenesss).

The agents (75%) think that the Ministry has no policy to promote the awareness of pollination and

pollinators in crop production.

Civil Society and Research Organisations: Knowledge of Pollination

Dino Martins

A survey of a biodiversity conservationists and practitioners, researchers and non-governmental or-

ganisations (NGOs) in Kenya was carried out to assess the level of knowledge of pollination services.

Questionnaires were sent to all members of the African Pollinator Initiative. Most respondents were

scientists, or technicians working for scientiﬁc institutions, and to a lesser extent, from conservation

civil society organisations.

Organisations involved in conservation programmes carried out their work through community

projects, public education and awareness and ecosystem management initiatives. Only two respon-

dents identiﬁed with species-focused programmes. This highlights an important trend towards a

community and public awareness focus in terms of the conservation message, and an overwhelming

endorsement of the ecosystem approach to management practice. This is important information for

the planning of pollination-related activities and projects.

Most of the respondents working in science and conservation have a basic knowledge of pollina-

tion as the process that transfers pollen and results in fertilization. People were also aware that pol-

lination requires an agent, but only two respondents identiﬁed these in this question as including

insects. While basic knowledge of what pollination is, as a process, is widespread, fewer people are

aware that many different organisms, and insects in particular, are important pollinators. Most or-

ganisations and individuals indicated that pollination or pollinators were included in some form or

aspect of their progammes. But the means of addressing pollination was limited to: bee keeping or

taxonomy. For example, one organisation encourages farmers to grow ﬂower-rich crops, including

sunﬂower and fodder trees to boost honey production. Education was seen as the main means to

incorporate knowledge on pollination and pollinators into agriculture and biodiversity conservation

projects. No organistion promoted any direct conservation needs and/or practices directly related to

pollinators. This is one area where much work can be done by API, in raising real awareness among

conservation and biodiversity-related practitioners.

Respondents identiﬁed the two most important training needs as bee/pollinator conservation (38%)

and pollination ecology/assessment (38%). Seventy percent of respondents felt that their knowledge

of pollination was only average, and 10% felt it was low. There is clear awareness of the need for

targeted education and awareness-raising among key groups- a need that API should seek to ﬁll.

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ROPS, BROWSE AND POLLINATORS IN AFRICA:

The above responses highlight the need for a lot of groundwork on pollinator awareness among

natural biodiversity practitioners and conservationists. Knowledge on the diversity of pollinators

and range of pollination systems needs to be improved. API has a real role to play in this, through

the dissemination of existing studies and building links with institutions that can go on to develop

further pollination-related programmes.

Identifying the State of Knowledge In the Literature

Barbara Gemmill-Herren

The literature covering pollination ecology in Africa is not new: articles were published as long ago as

1890 in South Africa, on the pollination of bananas, strelizias and Traveler’s palm. (Scott-Elliot 1890)

But it is, compared to other continents, fairly sparse and not with an applied aspect. As part of a joint

publication of the African Pollinator Initiative, a comprehensive literature review was carried out, com-

piling all known literature references to pollination studies in Africa (Rodger, Balkwill and Gemmill

2004). The review was published in a special issue of the International Journal of Tropical Insect Sci-

ence, dedicated to the African Pollinator Initiative. The bibliography is intended for widespread use by

those practitioners and research organizations contemplating pollination research in Africa. It will be

continually updated and maintained

as a searchable database on the API

website, currently hosted by PPRI in

South Africa at (http://www.arc.agric.

za/home.asp?pid=3493)

The review found that of 355 ar-

ticles (now up to 400, with further

searches and publications) focused

on different aspects of pollination

in Africa, the vast majority have fo-

cused on the evolutionary aspects of

pollination syndromes and breeding

systems (Figure 1). Less than one-

ﬁfth (72) addressed pollination in

agricultural systems, or with speciﬁc

crops. Research in Africa has iden-

tiﬁed interesting mutualisms, such

as that between ﬁgs and ﬁg wasps

and bats and various trees (Baijnath

et al., 1983, Compton 1990, Galil

and Esikovitch 1960). Yet applied,

agricultural aspects of pollination

have received much less attention,

and many of these studies remain in

the “grey literature”, not easily trace-

able or accessible to practitioners in

the ﬁeld.

IGURES 1 AND 2.

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N INITIAL STOCK-TAKING

Out of all the papers identiﬁed, only 93 included manipulative (experimental) work (Fig. 2). Pollina-

tion biology is a ﬁeld that lends itself readily to short-term, reasonably inexpensive manipulation

experiments that can put observations and hypotheses to a test. There is scope for considerably more

hypothesis testing and deductive science than has been conducted on the continent in pollination

studies up until now.

Given the paucity of speciﬁc information linking pollination services with crop production in Africa,

people wanting to know about pollination needs in Africa will turn to the standard reference volumes

on pollination ﬁrst. To assist with this, and to identify the prominent gaps in knowledge with respect

to African crops, the literature review also included the development of a table featuring the impor-

tant commercial commodities within Africa known to beneﬁt from animal vectors for pollination,

and where information on these can be found in these reference volumes this is indicated. As it is

increasingly recognised that pollination ecology is highly site-speciﬁc, and local, native pollinators

should be promoted over exotic solutions, we have added an additional column noting if and how

many pollination studies for a particular commodity have been carried out in Africa (Table 1). This

may help us to priortise future studies, to ﬁll in the obvious gaps.

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ROPS, BROWSE AND POLLINATORS IN AFRICA:

Table 1. Commodity Free Crane McGregor Known Studies

1996 & 1976 Pollinator(s) conducted

pages Walker from within

1984 literature Africa

pages

Grain legumes

Bambara groundnut, Self pollinated and self fertile

Voandzeia subterranea 342-3 73 - ants noted pollinating in Ghana 2

Broad beans,

Vicia faba var. major 298 23

/chap4/broad.html Self and bees 1

Common (ﬁeld) bean,

Vicia faba var. minor 298 23

/chap4/broad.html Self and bees 1

Cowpea, Vigna unguiculata 341-2 107

/chap4/cow.html Self and bees 2

Lima bean, Phaseolus lunatus 269-70 22

/chap4/lima.html Self and bees 0

Pigeon pea, Cajanus cajanus 317-20 107

/chap4/pig.html Probably self and bees

but not well known 2

Vegetables

Amaranth, Amaranthus spp. - - - Not known 0

Aubergine/eggplant, Bees other than

Solanum melongena 503-4 62

/chap6/eggplant.html honeybees 0

Chayote, Sechium edule - 40

/chap6/chayote.html Not known but

insects are necessary 0

Cucumber, Cucumis sativus 196-201 58

/chap6/cucumber.html Bees 0

Hot/sweet pepper, Self and bees-

Capsicum frutescens/annum 499-500 110

/chap6/pepper.html but not well known 0

Karela, Momordica charantia 208 -

/chap6/balsam.html Bees and beetles 0

Okra, 352-4 100

/chap6/okra.html Self, bees, wasps,

Abelmoschus esculentus ﬂies, beetles, birds? 0

Oyster nut. Telfairia pedata - - - Not known 0

French beans,

Phaseolus vulgaris 270 24

/chap4/beans.html Self and bees 0

Field peas, Pisum sativum 338-9 107 - Self and bees 0

Pumpkin, squash, marrow,

Cucurbita 203-7 69

/chap6/pumpkin.html Bees 0

Tomato,

Lycopersicon esculentum 492-8 137

/chap6/tomato.html Self and large bees 0

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N INITIAL STOCK-TAKING

Commodity Free Crane McGregor Known Studies

1996 & 1976 Pollinator(s) conducted

pages Walker from within

1984 literature Africa

pages

Fruit crops

Custard apple, cherimoya

Annona squamosa 129 40

/chap9/cherimoya.html beetles 0

Apple, Malus domestica 434-45 16

/chap5/apple.html Bees 0

Avocado, Persea americana 240-4 19

/chap5/avocado.html Bees, wasps, ﬂies 1

Borassus palm,

Borassus ﬂabellifer - 32 - Not known 0

Breadfruit, Artocarpus altilis 372 33 - Not well known 0

Cape gooseberry

Physalis peruviana 504 - - Not known 0

Carambola, Averrhoa carambola 391 35

/chap9/carambola.html Bees and other insects 0

Citrus, Citrus 479-85 44

/chap5/citrus.html Bees and other insects 2

Cherry, Prunus avium 431-66 41

/chap5/cherry.html Bees 0

Date palm, Phoenix dactylifera 401-2 61

/chap5/date.html Not known 0

Figs, Ficus carica 373-8 65

/chap5/ﬁg.html Fig wasps 2

Guava, Psidium guajava 386 73

/chap7/guava.html Self, bees, other insects 0

Litchie, Litchi chinensis 487-8 88

/chap5/litchi.html Bees, ﬂies, ants and wasps 1

Mango, Mangifera indica 124-8 90

/chap5/mango.html Not well understood 1

Marula, Sclerocarya birrea - - - Not known 0

Melon, Cucumis melo 190-6 92

/chap6/muskmelon.html Bees 0

Watermelon, Citrullus lanatus 201-3 93

/chap6/watermelon.html Bees 1

Natal Plum, Carissa grandiﬂora 131-2 98 - Not known 0

Papaya, Carica papaya 137-9 103

/chap5/papaya.html Hawkmoths,

skipper butterﬂies 3

Passion fruit, Passiﬂora edulis 408-9 104 /

chap5/passionfruit.html Large bees 0

Peach, Prunus persica 431-66 108

/chap5/peach.html Self and bees 0

Pears, Pyrus communis 431-66 108

/chap5/pear.html Bees 0

Plum, Prunus spp. 431-66 113

/chap5/plum.html Bees 0

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ROPS, BROWSE AND POLLINATORS IN AFRICA:

Fruit crops, continued

Commodity Free Crane McGregor Known Studies

1996 & 1976 Pollinator(s) conducted

pages Walker from within

1984 literature Africa

pages

Strawberry, Fragaria x ananassa 425-30 130 /chap7/strawberry.html Bees 0

Tamarind, Tamarindus indica 340-1 134 - Not known in Africa

(Apis dorsata in

Asia) 0

Nut crops

Cashew nut, Bees, ﬂies

Anacardium occidentale 122-4 37

/chap5/cashew.html ants 1

Macadamia nut, Bees,

Macadamia integrifolia 418-20 89

/chap5/mac.html wasps, beetles 0

Oil Crops

Castor, Ricinis communis 226-7 38 - Wind and bees 1

Coconut, Cocos nucifera 52 52

/chap5/coconut.html Wind and bees 1

Groundnut, Arachis hypogaea 314-7 72

/chap3/peanut.html Self but bees and thrips

seen to increase production

in Congo 1

Niger seed, Guizotia abyssinica 149,161 98

/chap9/niger.html Bees but not

well known 1

Oil Palm, Elaeis guineensis 398-401 99

/chap5/oil.html Beetles 5

Safﬂower, Carthamus tinctorius 145-8 123

/chap9/safﬂower.html Self and bees 0

Sesame, Sesamum indicum 410-11 127

/chap9/sesame.html Self and bees 1

Shea,

Butryospermum pardoxum - - - Not known 0

Soybean, Glycine max 325-9 27 /chap4/soy.html Self and bees 0

Sunﬂower, Helianthus annus - 132

/chap9/sun.html Bees and other insects 3

Beverage/stimulant crops

Cacao, Ceratopogonid midges,

Theobroma cacao 504-14 51

/chap5/cacao.html thrips, ants 12

Cola nut, - 81

/chap7/kolanut.html Flies-

Cola acuminata and nitida but not well known 1

Coffee, Coffea spp. 475-8 53

/chap7/coffee.html Self and bees 0

page 9

N INITIAL STOCK-TAKING

Commodity Free Crane McGregor Known Studies

1996 & 1976 Pollinator(s) conducted

pages Walker from within

1984 iterature Africa

pages

Fibre/container Crops

Cotton, Gossypium spp. 354-9 55

/chap9/cotton.html Self, but bees

increase production 3

Bottle Gourd, Lagenaria siceria 207-8 68

/chap6/white.html Hawkmoths, bees, bats 0

Kapok, Ceiba petandra 134-5 128 - Bats, hawkmoths 1

Rafﬁa palm, Raphia spp. - 117 - Not known 0

Forage Crops

Acacia tortilis pods - - - Bees other than honeybees,

butterﬂies, wasps 1?

Desmodium - Not known 1

Egyptian clover, or berseem,

Trifolium alexandrinum 271-97 30

/chap3/berseem.html Bees 7

Indigofera (browse in Africa) - - - Bees other than honeybees,

small butterﬂies 0

Stylosanthus - - Not known 0

Agroforestry crops

Calliandra calthyrsus - 35 - Bees 0

Gliricidium sepium - - - Not known 0

Grevillea robusta - 128 - Not known 0

Leucaena leucophala and hybrids - - - Not known 0

Sesbania sesban - - - Not known 0

Cosmetics

Bixa, Bixa orelllana (lipstick bush) - - Not known 0

Loofah sponge, 208 85

/chap6/veg.html Moths and butterﬂies,

Luffa cylindrica possibly bees 1

Pesticides

Mexican marigold, Tagetes lucida - - - Not known 0

Neem. Azadirachta indica - - - Not Known 0

Pyrethrum, Beetles, ﬂies, also bees; more

Chrysanthemum cinerariifolium 148 116

/chap9/pyrethrum.html potent insecticide derived when

ﬂowers visited by insects 2

page 10

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Rotenone, Tephrosia vogelii - 136

/chap9/tephrosia.html Not known 0

Spices

Black pepper, Piper nigrum 412-13 109

/chap9/black.html Not well known 0

Vanilla, Vanilla planifolia 389-90 141

/chap9/vanilla.html Specialised bees in area

where vanilla is indigenous;

largely by hand within

Madagascar and Africa 0

Pesticides, continued

Commodity Free Crane McGregor Known Studies

1996 & 1976 Pollinator(s) conducted

pages Walker from within

1984 iterature Africa

pages

page 11

N INITIAL STOCK-TAKING

FIGURE 3: INTERVIEW BOUQUETS

Estimating the pollination efﬁciency of different pollinators

requires that a ﬂower be exposed to a single pollinator visit,

from which the number of pollen grains can be compared to

a ﬂower receiving no visits. Rather than wait for a speciﬁc

pollinator to visit a ﬂower, it is possible to take the ﬂower

to the pollinator. In

this study, interview

bouquets were

used to assess

the contribution of

a single bee visit

to coffee and wa-

termelon. Flowers,

previously bagged

to ensure that no

pollination had

taken place, were

placed in a plastic

vial ﬁlled with water,

that was attached

to the end of a long

stick.

Assessments and Lessons Learned:

Methods and Approaches

An initial assessment of crop dependence on pollination services in Africa was carried out in Ghana,

Kenya and South Africa; three countries that are sufﬁciently different to capture the variation in

pollination needs.

In Kenya, field assessments were carried out in on farms near Thika town in the central

province, and in arid regions both near Tsavo, in the south-east, and Kerio Valley and Lai-

kipia Plateau just north of the equator. The areas have savannah and upland forest veg-

etation and two rainy seasons, April-June and November. The results for Kenya are to

be found in the chapters on Watermelon, Avocado, Acacia pods, Indigofera and Coffee.

Field assessments were carried out in the southwestern and central regions of Ghana in ag-

ricultural ﬁelds in clearings in the coastal rain forests. In this region, rainfall occurs through-

out the year, but mainly during March to August, during which it is very wet. Flowering,

however, is mostly in the dry season when pollinators are more active. The heavy, persistent

rains along the Ghanaian coast inhibit pollinator activity during the wet season. The re-

sults are reported in the chapters on Mango, Cashew, Coconut, Groundnut and Oil Palm.

In South Africa ﬁeld assessments were undertaken in the south-western region (around 34º00’S

19º00’E), among fold mountains. Here rainfall occurs in winter (June-August), and is often accompa-

nied by snow; the summers are hot and dry. The natural vegetation is cape macchia, but it is extremely

threatened and fragmented by agriculture, invasive plants and urbanization. The ﬂowering season for

crops and wild plants is mostly in spring (August to November). Deciduous fruits (peaches, plums,

apricots, pears and apples) were studied to better understand their pollination needs.

All these countries have rich pollinator

diversity, and where the activities took

place the conservation of this biologi-

cal diversity is a matter of concern. In

Ghana and South Africa the work took

place in Conservation International

biodiversity hotspots.

Small farmers were earmarked as the

primary beneficiaries of this survey,

but some of the assessment was done

on experimental or commercial farms.

This was mainly for logistic reasons,

because it is easier to plan surveys us-

ing systematically managed farms than

informal systems. The crops studied are

important to small farmer in the study

areas.

page 12

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Visual observation was used to determine what pollinates ﬂowers. The ﬂower visitors potential as

pollinators was recorded. The categories for pollinator potential are:

(1) = almost certainly a pollinator, e.g., a regular visitor whose pollen load comes into contact with

the stigma.

(2) = possibly pollinates on some visits, e.g., a regular visitor whose pollen load usually does not

come into contact with stigma.

(3) = unlikely, e.g., a wasp that may carry pollen but is unlikely to visit two ﬂowers of the same spe-

cies.

In some cases pollination efﬁciency was conﬁrmed using “interview bouquets” (see Figure 3).

In Kenya and Ghana, all observations of pollinators were standardised over time and space, by

observing ﬂowers for 10-minute periods, and counting the number of ﬂowers in a 1-meter square

area. This protocol has been followed in several pollination studies in Kenya and is permitting the

compilation of a large database on pollination observations. Where possible, similar observations

of pollinator visitation to wild plant species growing near the crop being studied were made to as-

sess alternative forage for the pollinators, but this component of the study merits much more time

devoted to it than was possible within this rapid assessment.

In South Africa, where crops known to be pollinated by honeybees were assessed, ﬁfteen pollen-col-

lecting honeybees were followed for ﬁve minutes and the number of blossoms visited by them during

this period was counted on each of the ﬁve species of fruit trees – peaches, plums, apricots, pears

and apples. The numbers and identities of other insect species visiting these same blossoms were

recorded (initially at 10 minute intervals, but the dearth of such pollinators and the overwhelming

presence of honeybees did not warrant continuation of this). This was to establish the comparative

attractiveness of the different blossoms to honeybees and other pollinators.

Similarly, ﬁfteen pollen-collecting honeybees were followed for ﬁve minutes as they visited the exotic

weeds, Echium plantagineum and Raphanus raphanistrum growing in adjacent plots. This to establish

whether the blossoms of these two weed species were more attractive to bees than fruit blossoms.

Other pollinators, besides honeybees, were collected and recorded from these two weed species.

The indigenous perennial spring ﬂowering plants growing mainly along the river banks but also

interspersed between the orchards were sampled for pollinators. Ten-minute counts were also made

of the number of the major pollinators visiting the most widespread of these species, viz. the Cape

marigold, Arctotheca calendula. Similarly, the Australian Acacia species and the South American bug-

weed (Solanum mauritianum) were inspected for pollinators. The indigenous plants would indicate

what pollinators were present and whether they also occurred on the deciduous tree blossoms and

those of the exotic weed species.

page 13

N INITIAL STOCK-TAKING

The presence or absence of honeybees on the exotic weeds would indicate their beneﬁcial or detri-

mental affect in allowing the build-up of colonies or by drawing bees from the possibly less attractive

deciduous species.

Manageability of pollinators was determined from the known life history of the pollinator. Pollina-

tion management for agriculture has been most successful with only a few organism groups, like

honey bees and leaf-cutter bees. This is because certain nesting behaviours, those that nest above

ground, lend themselves better to the development of pollination management technology. Africa

has several unique pollinators (like certain small carpenter bees) that have not been tried for crop

pollination, but have potential because they nest above ground in hollow sticks. Taxonomists and

pollination biologists together estimated the likelihood for pollinators to be managed.

This rapid assessment stressed the need to positively identify the ﬂoral visitors. Specimens were

collected for identiﬁcation in the course of ﬁeld observation, and sent to taxonomic experts for iden-

tiﬁcation down to species if possible. In addition a key to the African genera of bees was developed,

and around ﬁfteen ﬁeld researchers and parataxonomists were trained in Kenya and Ghana on the

use of the key.

page 14

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Fruit crops: Deciduous Fruit

in South Africa

Geoff Tribe

The rapid assessment of deciduous fruit in South

Africa was carried out in a region that indicates

the future of pollination services in Africa: it is

a region that, through a combination of human

disturbance and native ecology, is not rich in

bees, and farmers pay for pollination services.

The south-western Cape has been intensely

cultivated for about 350 years, when a re-

freshment station was established to service

ships passing the Cape of Good Hope. The

existing landscape has changed due to the

introduction of European crops and farming

methods, and by the introduction of many

invasive weed species. Today the major crops

of this region include winter wheat, grapes

and fruit. Only marginal land, often on steep

slopes, has not been cultivated, and much of the region has been invaded by alien plant species.

The two study sites were in the Franschhoek Valley on the farm Bien Donné, presently managed

by the Department of Agriculture, and an apple orchard located at the Elgin Experimental Farm

at Grabouw. The farm Bien Donné consists of peach, plum, apricot and pear orchards, with a

small area devoted to the production of lavender (Lavandula sp.) oil. Small patches of indigenous

and exotic vegetation occur around the periphery of the farm and along the river that bisects the

property. On this farm were at least six natural swarms of the indigenous honeybee, Apis mellifera

capensis Escholtz, located in oak trees, and two hives were situated near the lavender ﬁeld. The El-

gin Experimental Farm is surrounded by natural montane fynbos. No honeybee colonies had been

brought in for pollination and what honeybees there were came from wild swarms in the vicinity.

Despite the low insect biomass in the fynbos region (Schlettwein and Giliomee 1987) and the

apparent scarcity of pollinating insects, the majority of fynbos plants (about 83% according to

Steiner (1987)) are insect pollinated (Whitehead et al. 1987). Despite the ﬂoral diversity of the

fynbos, the region does not appear to have a particularly rich bee fauna (Michener 1979), al-

though beetles are an important and conspicuous component of the insect pollinator fauna in

fynbos (Johnson 1992). Butterﬂies are not common in fynbos probably because the sclerophyllous

vegetation with its low nitrogen content is unsuitable for phytophagous larvae (Cottrell 1985).

Growers of apples and pears in the south-western Cape regard the presence of honeybees brought

in for that purpose as essential for full pollination of the crop. This also ensures that each fruit is of

a large and uniform size, and properly formed, which are essential requirements for export grade.

FIGURE 4: P

EACH TREES

IN SOUTH AFRICA.

page 15

N INITIAL STOCK-TAKING

When ﬂowers of some varieties are inadequately fertilized they develop into misshapen fruits,

and immature fruits with relatively few seeds, which are more inclined to be shed later than

ones with many seeds (Free 1970). Certain cultivars of pears are regarded as unattractive to

honeybees who rapidly ﬁnd more proﬁtable forage in the vicinity of the orchard and this ne-

cessitates that a second batch of honeybee colonies are brought in midway during the blos-

som period. Abundant pollen is released but the nectar is not attractive because it has a low

sugar content – recorded as 8-10% (Crane & Walker 1984). Most varieties of apple, pear

and plum are self-unfruitful, whereas peach and apricot are largely self-fruitful (Free 1970).

Fruit farmers pay beekeepers to place honeybee colonies within their orchards to ensure full pol-

lination. The parasitic Asian mite Varroa destructor Anderson & Trueman (Acari: Mesostigmata) which

destroys honeybee brood was discovered in South Africa in 1997 and rapidly spread throughout

the country (Allsopp et al. 1997). Presently the destructiveness of this mite in South Africa (Martin

& Kryger 2002) is not nearly as severe as that reported amongst European races of honeybees in

both Europe and the Americas. The question arises that had honeybees been totally or partially

debilitated by this mite (or a disease in the future), are there alternative indigenous pollinators that

could replace them?

EACHES (PRUNUS PERSICA (L.) BATSCH.)

Peach blossoms (Figure 4) were almost 100% pollinated by the indigenous honeybee Apis mel-

lifera capensis. A few syrphid (Metasyrphus sp. 1;Ischiodon aegyptus (Wiedemann)) and black ﬂies

(Bibio turneri Edwards) frequented individual ﬂowers to obtain nectar but spent most of their

time patrolling leaves and can therefore only be regarded as occasional pollinators at best. Hon-

eybees systematically worked the ﬂowers for the ﬁrst three days after the trees began to blossom,

and pollen collectors were especially frequent. After the ﬁrst three days the pink blossoms began

to deteriorate (after been fully pollinated) and visits by honeybees, especially pollen collectors

declined rapidly. The nectar collectors then tended to move rapidly between trees and rows if

no reward was forthcoming. This pattern was followed on all the deciduous fruit tree species.

All peach cultivars are self-compatible and therefore do not necessarily require pollinators, but pol-

linating insects are of value even for the self-fertile cultivars (Crane and Walker 1984). Peach trees

originate in the Near East and as such fall within the distribution range of the Western Honeybee,

Apis mellifera. Yellow ﬂowers are most attractive to insects. The peach ﬂowers do not discriminate

between ﬂoral visitors (as do for example the constricted tubular ﬂowers of some Aloe species) and

their pollen and nectar are readily exposed.

TABLE 2. NUMBER OF BLOSSOMS VISITED BY

A SINGLE HONEYBEE IN FIVE MINUTES.

Crop Date T range No. Total no. Mean no.

C visits blossoms blossoms

visited visited

Peaches 06/08/03 13 – 21 15 223 14.8

Plums 28/08/03 9 – 17 15 697 46.4

Apricots 25/09/03 13 – 25 15 576 38.4

Pears 26/09/03 14 - 25 15 756 50.4

Apples 21/10/03 22 - 32 15 638 42.5

Rhamnas 06/08/03 13 – 21 15 515 34.3

Echium 06/10/03 14 - 23 15 508 33.8

page 16

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Arctotheca calendula(Cape Marigold) Hymenoptera Specidae Dasyproctus sp.

Scoliidae

Campsomeris sp.

Andrenidae

Andrena sp.

Colletidae

Scrapter pallidipennsi (Cockerall)*

Colletidae

Scrapter caesariatus Eardley

Colletidae

Scrapter heterodoxus (Cockerell)*

Halictidae

Patellapis (Lamatalictus) sp.*

Halictidae

Patellapis (Zonalictus) sp. 1

Halictidae

Patellapis (Zonalictus) sp.2

Halictidae

Patellapis (Zonalictus) sp. 3 ***.

Halictidae

Halictus (Seladonia) sp

Apidae

Ceratina (Ceratina) sp.

Diptera Bibionidae

Bibio turneri Edwards*

Empididae Sp. 1

Empididae Sp. 2

Bombyliidae Sp.

Muscidae

Orthelia ringiaeformis (Vileneuve)

Syrphidae

Betasyrphus sp.*

Syrphidae

Metasyrphus sp. 1

Syrphidae

Metasyrphus sp. 2*

Syrphidae

Eristalis sp.

Anthomyiidae

Delia sp.*

Coleoptera Phalacridae

Olibrus sp.

Cleridae Sp.

Cleridae Dolichopsia cf. cyanella Gorham

Melyridae

Pagurodactylus sp.

Melyridae

Pagurodactylus angustissimus Pic

Tenebrionidae

Eutrapela sp.*

Melolonthinae Sp.1

Melolonthinae Sp.2

Melolonthinae Sp.3

Melolonthinae

Pachycnema pulverulenta Burmeister

Anthicidae

Formicomus caeruleus (Thunberg)

Meloidea

Ceroctis capensis (Linné)

Cerambycidae Cf

. Promeces sp.

Buprestidae

Acmeodera decemgutta (Thunberg)

Nitidulidae

Meligethes cf. variabilis Reitter*

Dermestidae

Attagenus nr.

auratofasciatus Reitter

Dermestidae

Attagenus cf. breviusculus (Reitter)

Chrysomelidae Sp.

Chrysomelidae

Oulema erythrodera (Lacordaire)

Chrysomelidae

Eurythenes sp.

Raphanus raphanistrum (Wild radish) Hymenoptera Eumenidae Delta sp.

Colletidae

Scrapter heterodoxis (Cockerell)*

Halictidae

Patellapis (Lamatalictus) sp.*

Lepidoptera Pieridae

Colias electo electo (Linnaeus)

Pieridae

Dixeia sp.

Nymphalidae

Cynthia (Vanessa) cardui (Linnaeus)

Diptera Empididae Sp.1**

TABLE 3. INSECTS VISITING THE FLOWERS OF VARIOUS PLANTS AT BIEN DONNÉ (FRANSCHHOEK) AND GRABOUW

WHICH WERE SIMULTANEOUSLY IN FLOWER WITH FIVE ORCHARD TREE SPECIES. ASTERISK * DENOTES NUMBER OF

ADDITIONAL PLANT SPECIES FLOWERS THEY VISITED.

FLOWERING PLANT INSECT VISITOR

ORDER FAMILY SPECIES

page 17

N INITIAL STOCK-TAKING

The low mean number of 14.8 peach blossoms visited in ﬁve minutes is largely because of the long

time taken by the bees to pack the pollen on their bodies into the pollen-baskets, and to the cold

days prior to the day records were taken (Table 2). This may also be reﬂected in the blooms appearing

in very early spring when most insects have yet to start foraging.

LUMS (PRUNUS DOMESTICA L.)

Plum blossoms were pollinated almost exclusively by honeybees. The relatively large mean number

(46.4) of ﬂowers visited in ﬁve minutes by honeybees (Table 2) can partly be ascribed to the clustering

of blossoms about which the honeybees clambered without having to ﬂy to each individual blossom.

An insigniﬁcantly small number of syrphid ﬂies (Ischiodon aegyptus (Wiedemann)) visited ﬂowers to

collect nectar at infrequent intervals.

In Europe, honeybees are the primary pollinators because plums bloom in early spring when popula-

tions of other insect species are low. A high population of pollinators is required to produce a high

fruit yield because the pollen grain must come from another compatible ﬂower and at the right time

(Crane and Walker 1984).

PRICOT (PRUNUS ARMENIACA L.)

Honeybees were the almost exclusive pollinators of apricot ﬂowers. The mean number of ﬂowers

visited by an individual honeybee in ﬁve minutes was 38.4, which was slightly lower than expected.

In a study in Australia, honeybees comprised over 97% of insects on the ﬂowers and improved fruit

set and yield (Langridge and Goodman 1981).

EARS (PYRUS COMMUNIS L.)

The recommended pollination strategy for the commercial pollination of pears is to bring in two

waves of honeybee colonies because the ﬂowers of many cultivars are reported to be unattractive

to bees. However, the pears (early Bon Chretien cultivar) at Bien Donné proved to be so attractive

Syrphidae Betasyrphus sp.*

Coleoptera Cleridae

Dolichopsis cf. cyanella Gorham

Zantedeschia aethiopia (Arum lily) Diptera Empididae Sp.1

Tipulidae Sp.

Coleoptera Melyridae Cf.

Troglops

Melyridae Pagurodactylus sp.

Cleridae

Dolichopsis cf. cyanella Gorham

Cleridae

Notostenus viridis (Thunberg)

Tenebrionidae

Eutrapela sp.

Melolonthinae Sp.1

Melolonthinae

Peritrichia albovillosa Schein

Meloidea

Ceroctis capensis (Linné)

Nitidulidae

Meligethes cf. variabilis Reitter*

Cenia turbinate (Goose daisy) Hymenoptera Colletidae Scrapter pallidipennsi (Cockerell)*

Vicia atropurpurea Purple vetch Hymenoptera Halictidae Patellapis (Zonalictus) sp. 3***

Vicia sativa Broad-leaved purple vetch Hymenoptera Halictidae Patellapis (Zonalictus) sp.3***

Diptera Anthomyiidae

Delia sp.*

Solanum mauritianum (Bug-weed) Diptera Syrphidae Metasyrphus sp.2*

Lupinus luteus (Yellow lupin) Hymenoptera Halictidae Patellapis (Zonalictus) sp.3***

FLOWERING PLANT INSECT VISITOR

ORDER FAMILY SPECIES

page 18

ROPS, BROWSE AND POLLINATORS IN AFRICA:

to honeybees that the highest mean number of 50.4 of ﬂowers visited by a single bee in ﬁve min-

utes was recorded. Honeybees again proved to be almost exclusive pollinators of pears. The pollen

baskets also contained the largest accumulation of pollen. It has been recorded that the nectar of

pears is not attractive because it has a low sugar content (8-10%) but supplies abundant pollen that

is highly attractive to honeybees (Crane and Walker 1984).

PPLES (MALUS DOMESTICA BORKH.)

At the Elgin Experimental Farm at Grabouw, it was shown that 98.2% (n=1254) of the pollinators

were honeybees. The other 1.8% insects occurring on the blossoms consisted of syrphid ﬂies (5),

painted lady butterﬂies Cynthia (Vanessa) cardui (5), blowﬂies (5), solitary bees (2), a twig wilter (1),

a lacewing (1), a wasp (1), a blackﬂy (1), a houseﬂy (1), and the carpenter bee Xylocopa capitata (1).

But this underestimates the effectiveness of the honeybees because there is no comparison between

them and these other insects in pollination efﬁciency. Most visitors other than honeybees visited

apple blossoms only erratically.

XOTIC WEEDS

The exotic weeds adjacent to the deciduous fruit crops were surveyed to assess to what degree they

provide alternative resources for the crop pollinators. None of the Australian Acacia species grow-

ing along the river banks and elsewhere (within 5 to 50 metres from each orchard) were visited by

any pollinators over the observation period. The Australian stink bean Paraserianthes lophantha at-

tracted a few honeybees that foraged for pollen, but no other pollinators were recorded. Two exotic

weed species that were highly attractive to honeybees were Echium plantagineum from Europe and

Asia, and wild radish (ramnas) Raphanus raphanistrum from Europe. The mean number of ﬂowers

visited by individual pollen-collecting honeybees in ﬁve minutes was 33.8 for Echium and 34.3 for

Raphanus (Table 2).

These latter two exotic weeds may be important for honeybees, and also for other members of the

pollination community: adjacent to the river where Ramnas grew amongst indigenous vegetation,

a far greater number of insect species visited these plants although honeybees still predominated.

These included solitary bees, xylocopids, wasps and several small beetle species.

NDIGENOUS FLOWERING PLANTS

Indigenous ﬂowering plants in farm margins were also surveyed to assess to what degree they pro-

vide alternative resources for the crop pollinators. The most prevalent indigenous plant ﬂowering

during this time was the Cape Marigold Arctotheca calendula. Other species included a Senecio sp., the

Arum lily, Zantedeschia aethiopia, and yellow sorrel, Oxalis pes-caprae. Few of these indigenous plants

were attractive to honeybees, although many- such as Cape marigold- were important resources for

solitary bees and syrphid ﬂies, among other pollinators.

CONCLUSIONS

All ﬁve species of deciduous fruit trees were thoroughly pollinated almost exclusively by honeybees,

which comprised over 98% of all pollinators recorded on these trees. This is even an underestimation

of the effectiveness of the honeybees because the other insects recorded on the blossoms, such as

the odd Xylocopa caffra (Linnaeus), Xylocopa capitata Smith or solitary bee,

page 19

N INITIAL STOCK-TAKING

although effective as pollinators, visited only a few blossoms and could in no way match the efﬁ-

ciency of the honeybees. The few ﬂies (syrphids and Muscidae, Orthellia ringiaeformis (Villeneuve)),

and beetles observed on the blossoms were only occasional visitors and inefﬁcient pollinators and

collected nectar usually without touching the anthers of the blossom.

In the course of gathering these observations, it was noted that both nectar and pollen was collected

from all the deciduous fruit species except for apples where 98.2% of the foragers were collecting

nectar only. This is conﬁrmed by the fact that only honeybee colonies placed on apples for pollination

purposes produce any honey (Mostert, pers comm.). The Bon Chretien pear trees were especially

attractive as suppliers of pollen and the pollen-baskets of the honeybees were packed high with the

greyish pollen. The pollen produced by the apples was not attractive to the honeybees.

Honeybees visited alternative ﬂoral resources at a lower rate than they visited the fruit species (ex-

cept for peach). Nonetheless they clearly obtained ﬂoral resources from Echium and Ramnas, and

also serve as pollinators at least of the Echium where they emerge from ﬂowers coated in a ﬁlm of

blue pollen.

Plants originating in Europe and Asia, where Apis mellifera naturally occurs, did have a beneﬁcial affect

on both the Cape honeybee and several indigenous solitary bee species and produced both nectar

and pollen. Not only do honeybees ﬁnd Echium and Ramnas highly attractive, but so do indigenous

bees which also frequent Vicia spp.

With the recent expansion of the fruit growing area in South Africa, there is presently a shortage

of pollination units available for deciduous fruit. Part of the problem lies in the systematic removal

of Eucalyptus trees, which were classiﬁed as invader species but were the most important source of

nectar and pollen to tide colonies over the summer dearth period. So plant species that contribute

to the well being of honeybee colonies are beneﬁcial. There was no indication that honeybees were

enticed away from the fruit blossoms by the exotic weeds, and the indigenous solitary bees also

beneﬁted by the presence of these ﬂoral resources.

Honeybees are indispensable as pollinators of deciduous fruit in the south-western Cape and should

they be afﬂicted by a debilitating disease or other parasites, the export fruit industry will be severely

affected. Continued efforts to document alternative pollinators, and alternative ﬂoral resources for

honeybees and other potentially important pollinators, will be useful.

page 20

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Kenya is within the probable area of domestication of watermelon (Citrullus lanatus), yet no pol-

lination work on the plant has previously been carried out in the region. One of the members of

the African Pollinator Initiative, Grace Njoroge, is pursing a PhD on the topic of watermelon pol-

lination in the region of Yatta. The majority of her study has focused on the behaviour and patterns

of honeybee pollination of watermelon, as these are by far the predominant visitors. But through

the support of the FAO Rapid Assessment project, we were able to supplement her ﬁeld observa-

tions with several days of deliberate, focused observations on alternative pollinators of watermelon.

The Yatta Plateau of Kenya, to the east and below the important agricultural town of Thika, is intensely

farmed by smallholders and some large estates. The region, though fairly dry, is dissected by rivers

and also fortunate to have a major engineering work, the Yatta Furrow, running near the top of the

ridge between two valleys, diverting water from the Thika river to farms along the plateau. Although

the region is arid, the furrow permits irrigation of crops such as coffee and watermelon.

On both of the farms in Yatta region where informa-

tion was collected on pollination, honeybees were

by far the most numerous and thus important as

pollinators for watermelon. Yet, the national youth

service farm at Yatta where we observed watermelon

pollination, does not keep bees. Thus farmers in the

region rely on wild bee colonies, of which several

can be seen in riparian zones on farms in this region.

Unfortunately, the National Youth Farm has em-

ployed its many young workers to clear ﬁelds to the

river, and have greatly reduced the riparian zones.

Female watermelon ﬂowers are much less abun-

dant than male ﬂowers (Figure 6), and also appear

to be less visited by honeybees. The team observing

watermelon for non- Apis visitors thus separated

observations of male and female ﬂowers to see if

this held true with other ﬂower visitors. As with

the other investigations within Kenya, watermelon

ﬂowers were observed in the ﬁeld over 10-minute

intervals of time, at all times of the day, and in this

case over six days. The non-honeybee visitors

to watermelon ﬂowers included those in table 4.

Female ﬂowers were considerably less frequently

visited by both non- Apis bees and ﬂies, as well as

by honeybees (Figure 5).

IGURE 5: NON-APIS VISITATION

PATTERNS TO WATERMELON, YATTA

FIGURE 6: MALE FLOWERS,

ATERMELON

Watermelon in Kenya

Grace Njoroge, Laban Njoroge, and Barbara Gemmill-Herren

page 21

N INITIAL STOCK-TAKING

However, if we consider the ratio of male to female ﬂowers (13:1), then it is evident that particularly

in the case of non-Apis bees, the visitors are actually preferring and seeking out the female ﬂowers.

Interestingly, at least two of the non-honeybee bee pollinators in the watermelon ﬁeld were found

nesting in the soil of the ﬁeld. If nesting habits can be observed more closely, land management

practices could be prescribed to best conserve these nests on-farm.

Indigenous bees pollinating watermelon at Yatta, in Kenya- aside from honeybees - show appropri-

ate pollination behaviour, and evidently are able to make use of conditions on-farm to nest. While

soil-nesting bees may be among the hardest to manage, the fact that they are already able to nest

within a ﬁeld suggests that management procedures to ensure their survival could be developed.

TABLE 4. VISITORS TO WATERMELON FLOWERS

   

Order Family Subfamily Genus Species

(a) Bees

Hymenoptera Halictidae  Lasioglossum sp.A

Hymenoptera Halictidae  Lasioglossum sp.B

Hymenoptera Halictidae  Lipotriches sp.

Hymenoptera Apidae  Apis melifera

(b) Other visitors    

Diptera Syrphidae Syrphinae Allobaccha sp.

Diptera Syrphidae Syrphinae Allograpta nasuta

Diptera Syrphidae Syrphinae Betasryphus adligatus

Diptera Calliphoridae Chrysomyinae chrysomya chloropyga

Diptera Calliphoridae Chrysomyinae chrysomya sp.

Diptera Calliphoridae Calliphorinae Hemipyrellia sp.

page 22

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Mango in Ghana

Peter Kwapong

Mango (Mangifera indica L.) is one of the most important fruit crops world wide. The major pro-

ducing areas of Mango include: United States of America (Florida), Mexico, Central America, West

Indes (Caribbean Islands), South America (Brazil), Africa (Tanzania, Zaire), Arabian Peninsula, Asia

(India, Pakistan, Philippines, Indochina and Indonesia). There are about 150 varieties of mango

grown world wide. The plant is very important for its high economic value and as foodstuff for the

inhabitants of the tropics. The fruits of mango are eaten fresh or canned. They are used to make

fruit drinks. The unripe fruit is used in pickles. The stem bark is boiled with shea-butter and used

to treat bronchial disorders in children. In Ghana, both local and improved varieties of mango are

grown for local use and for export.

Mangos belong to the family Anacardiaceae. It is a large evergreen tree which can live for over 100

years. Mangoes grow best at altitudes below 1,500 metres, rainfall of 1.500 mm per year, and with

very little variation in day and night temperatures.

Mango ﬂowers (Figure 7) occur in a conical panicle up to 45 cm long depending on the variety and

environmental conditions during its development. The panicle bears 500 – 600 ﬂowers. Both bisexual

and male ﬂowers are present on the same panicle. However, their proportions depend on the variety

and temperature during its development. The size of both male and hermaphrodite ﬂowers varies

from 6-8 mm in diameter. They are subsessile

and have a sweet smell.

Mango produces relatively small amount of

pollen per ﬂower. The mango (hermaphroditic)

ﬂower is such that any organism that lands on

the ﬂower is likely to effectuate pollination. The

ﬂower opens early in the morning. Maximum

pollen shedding is from about 8 am to noon. The

ﬂowers secrete nectar in considerable quantities.

This attracts a large number of insects.

IGURE 7: INFLORESCENCE AND IMMATURE

FRUITS OF MANGOES

page 23

N INITIAL STOCK-TAKING

Sites selected for research into the pollination of mango include: Dodowa, a major mango growing

area and Cape Coast. These locations are in the Greater Accra and Central Regions respectively.

About 29 species of dipteran ﬂies were collected. These seem to be the main pollinators even though

bees and wasps were also found on the ﬂowers. Apart from honeybees, 4 other bee species and 7

species of wasps were also collected from the ﬂowers. Three species of chrysomelid beetles, and some

Lepidoptera were also collected. No alternative host ﬂowering plants were found around since the

vegetation was mainly grass.

TABLE 5. FLORAL VISITORS TO MANGO, GHANA.

Species observed Score Notes

Apis melifera (honey bee) 1 Visited early from 7.30 am and took over the

pollination of mango

Halictidae (Pseudalpis sp) 1 Collected on ﬂowers

Dactyrarina sp (Stingless bee) 1 Collected on ﬂowers

Wasps (9) 1-2 Collecting nectar

Syrphidae (2) 1-2 Hovering and occasionally landing on

ﬂowers

Calliphoridae 1-2 Walking over ﬂowers

Muscidae (4) 1-2 Walking over ﬂowers

Coleoptera 1-2 Were many on ﬂowers in the evening from

(brown soft bodied) 5.00pm

Arctiidae,,Ctenuchinae,

Euchromia sp (Moth) 1-2 Flying over trees with occasional landing on

ﬂowers

Chrysomelidae (2) 2-3 Feeding on plant material

Dolichopodidae 3 Walking over ﬂowers

Ichneumonidae (1) 3 Parasitoid, predating on other insects

page 24

ROPS, BROWSE AND POLLINATORS IN AFRICA:

FIGURE 10: HERSE CONVOLVULI (WITH TONGUE EXTENDED)

––

ONE OF THE HAWKMOTHS POLLINATING PAPAYA

FIGURE 8: MALE FLOWER OF PAPAYA

FIGURE 9: FEMALE FLOWER OF PAPAYA

Papaya in Kenya

Dino Martins

Papaya (Carica papaya), also known as paw-

paw, is a widespread fruit crop throughout

Kenya where enough water is available for

it to be cultivated. It is a perennial tree crop,

dioecious, i.e., separate male and female

ﬂowers, and therefore requires a pollinator

in order to set fruit. In tropical and sub-

tropical climates, fruit set occurs throughout

the year. Papaya is sold and eaten locally

as a fresh fruit, with much demand from

the numerous hotels, local grocery stores

and the town markets. Papaya is dried and

exported as part of a dried fruit mixture. The

‘milk’- a latex produced by the unripe fruit

is harvested and used in the production of

papain, an enzyme that acts on protein.

Papain is used in the brewing industry,

canned meats and medicinally. Coastal

peoples also use the latex from unripe fruit

to ease the pain and remove the spines and

stinging cells of sea-urchins and jellyﬁsh.

The seeds are dried and exported to health

food stores.

In some areas, the leaves are used to wrap

meat, which is then roasted. This is said

to act as a tenderiser and improve ﬂavour.

Unripe fruits are also boiled and eaten as

a vegetable by some communities. Sale of

fresh papaya across Kenya provides some

regular income for farmers. Single fruits

are sold for between 20-100 Kshs ($ 0.26-

1.3), depending on the location and local

abundance or availability of fruit. Most

small-holder farms produce at least ﬁfty

individual saleable fruits a season.

Papaya pollination observations (Table 6)

were made in multiple sites including the

following: Kerio Valley, Machakos, Kitisuru

(Nairobi), Kitengela and Mosoriot (Eldo-

ret).

page 25

N INITIAL STOCK-TAKING

The Kerio Valley had the largest stands of trees, with farms near rivers supporting hundreds of trees

and supplying fruit to traders in lorries. Fruits are transported to Nairobi and other towns

The Papaya plant is a relatively fast-growing species. It reaches a height of several metres. Papaya

requires pollination to set fruit. There are separate male and female ﬂowers (Figures 8 and 9), as a

rule, on separate trees. Occasionally hemaphrodite trees are found. The male ﬂowers on ‘male’ trees

are smaller but are produced in larger numbers than female ﬂowers.

TABLE 6. FLORAL VISITORS TO PAPAYA, KENYA

Species observed Notes/observations/sites where present

Diptera

Calliphoridae Occasional diurnal visitors to female ﬂowers.

Not pollinating. (All sites studied).

Tephritidae: Didacus sp. Common diurnal visitor to female ﬂowers.

Not pollinating. May be laying eggs in young

fruit. (Kitisuru and Kerio valley)

Hymenoptera

Apidae:Apis mellifera Occasional visitor to male ﬂowers. Not

pollinating. (Kerio valley)

Lepidoptera

Hesperiidae:Ceoliades sp. Occasional diurnal visitor to both male and

female ﬂowers. Some pollen transport.

Pollinator. (Kerio valley)

Sphingidae: Hippotion celerio Abundant ﬂoral visitor. Seen at both male

and female trees. Hovers while feeding.

Pollinator (Kerio valley, Machakos and

Kitengela)

Sphingidae: Herse convolvuli Abundant ﬂoral visitor. Seen at both male

and female trees. Hovers while

feeding. Pollinator (Mosoriot and Kitengela)

Sphingidae: Macroglossum trochilus Abundant ﬂoral visitor. Seen at both male

and female trees. Hovers while

feeding. Diurnal. Pollinator (Mosoriot)

Sphingidae:Daphnis nerii Abundant ﬂoral visitor. Seen at both male

and female trees. Hovers while feeding.

Pollinator (Mosoriot)

Sphingidae:Nephele comma Abundant ﬂoral visitor. Seen at both male

and female trees. Hovers while feeding.

Pollinator (Machakos)

Noctuidae: Sphingomorpha chlorea Occasional ﬂoral visitor. Hovers

and alights on ﬂowers. Pollinator (?)

(Kitengela and Kitisuru)

page 26

ROPS, BROWSE AND POLLINATORS IN AFRICA:

They are produced in small bunches on short panicles originating from the trunk in-between the

leaf-bases. Female ﬂowers occur single at the base of leaves appressed to the trunk. Both ﬂowers

offer nectar rewards to pollinators.

Given the dioecious nature of the trees, both male and female ﬂowers were observed during this

pollination assessment study. Floral production of fragrance and ﬂoral visitor activity is highest

after dusk, and before eight p.m. Flowers were watched for between 30 minutes to an hour at each

site studied (generally after sunset). Initial observations indicated little pollinator activity during the

day. Diurnal visitors included fruit ﬂies and calliphorid ﬂies (female ﬂowers). Occasional honeybees

visit (male ﬂowers) and ﬂower moths visit (female ﬂowers). One large species of skipper butterﬂies

(Hesperiidae), were observed visiting during the day at one location. They visited both male and

female ﬂowers. This is important for transfer of pollen.

The pollination of the dioecious ﬂowers is primarily carried out by crepuscular/nocturnal moths

(Sphingidae). These moths, better known as hawkmoths or sphinxmoths, are fast-ﬂying, large and

highly mobile insects (Figure 10). This makes them extremely efﬁcient pollinators. Preliminary ob-

servations on Kenyan farms show that different moth species are responsible for pollination across

different sites. Pollination happens primarily after dusk, within an hour or so. This is a fairly narrow

window and only the hawkmoths visit both male and female ﬂowers at this time, and are able to

cover the distances between trees and plantations quickly.

page 27

N INITIAL STOCK-TAKING

Avocado in Kiambu, Central Kenya

Wanja Kinuthia and Laban Njoroge

The avocado tree originated in Central America, where it co-evolved with native pollinators. Effec-

tive pollinators, whether co-evolved or not must be adapted to visit both male and female ﬂower

stages, coming in contact with the dehisced anthers and receptive stigma at the same pollen col-

lection zones. Small and medium ﬂying insects (3-8 mm in length) are especially apt to efﬁciently

collect avocado nectar.

Avocado is currently grown in most countries in the world. According to Wysoki et al. (1997), the main

avocado producing countries in Africa are South Africa, Democratic Republic of Congo, Cameroon,

Kenya, Egypt and the Canary Islands. Kenya is among the top exporting countries in Africa mainly

to France, Germany and United Kingdom (Collin, Pers. comm.)

The avocado ﬂower is small and has both male and female reproductive organs. The ﬂowers are

carried on terminal panicles. Each panicle carries a few hundred ﬂowers. All cultivars have similar

ﬂower structures though they may differ slightly in ﬂower size.

An individual avocado ﬂower goes through two stages. When it opens in stage I, the pistil is receptive,

and pollination and fertilization can occur. The ﬂower closes after stage I and opens again in stage

II when the anthers dehisce. Avocado cultivars ﬁt into two general types according to the time of

day their ﬂowers are in different stages. The ﬂowers of type A cultivar are in stage I in the morning

of the ﬁrst day and stage II in the afternoon of the following day, so that the ﬂower’s opening cycle

lasts about 36 hours. Type B cultivar are in stage I in the afternoon of the ﬁrst day and stage II in the

morning of the following day. The ﬂower opening cycle lasts about 20 hours (Free 1993). A farmer

with type A and B is ideal so that, in the morning, type A are pollinated with pollen from type B trees

and in the afternoon, type B would receive pollen from type A.

Self-pollination is possible because ﬂowering dichogamy is rarely absolute: opening and closing of

ﬂowers of the same tree is not necessarily perfectly synchronized. Therefore, early opening ﬂow-

ers may overlap with late opening ones (Free 1993). Even when self-pollination within a tree is

possible, insects are needed to transfer the pollen between ﬂowers. The three types of pollination:

cross, close and self-pollination occurs in avocado. Robbertse et al. (1996) were able to demonstrate

a clear advantage of cross over self-pollination.

A pollination survey was conducted on six trees of “Hass” and “Fuerte” varieties, in Kiambu District

Central Province. This site was chosen because the plants had ﬂowers at eye-level for ease of ob-

servation (Table 7).

The honeybee, Apis mellifera L. was clearly the most proliﬁc visitor on avocado ﬂowers, visiting in

much larger numbers than other visitors. Honeybees appeared in the morning between 6:00 to 10:00

and never to return again until the following day. There were various species of ﬂies observed visiting

the ﬂowers. Flower beetles and ants were also observed (Table 7). Although ants were permanently

on the ﬂowers, they appeared less effective as pollinators as they rarely came into contact with the

anthers and stigma of the ﬂower. They were also observed to deter

page 28

ROPS, BROWSE AND POLLINATORS IN AFRICA:

other would-be effective pollinators from visiting the ﬂowers due to their intimidating large num-

bers. The ants also deplete the nectar from ﬂowers, making other visitors spend very little time on

ﬂowers. Farmers often band their Avocado trees with appropriate products to keep the ants away.

The variety of species observed on the avocado ﬂowers in Gachie, Kiambu are shown on Table 7.

However, the pollination efﬁciency for each species was not carried out in this study.

Though avocado is an exotic tropical fruit to Kenya, its reproduction has adapted well to the local

pollinators as shown in this study. The exposed ﬂower with large amount of nectar and pollen at-

tracts a large number of visitors. The area of study is densely populated, where most farms are less

than four acres. The farmers keep cattle in near to zero-grazing level, and are averse to bee keep-

ing according to a survey reported elsewhere in this study. The only other ﬂowering plants were

the Lantana sp. hedge surrounding the farm. In spite of this, the honeybees A. mellifera visited the

ﬂowers abundantly followed by several genera of Diptera. Ants, ﬂower beetles and wasps were

also observed. The study should be repeated and the sampling period extended to cover the entire

ﬂowering period. It would be interesting to compare Kiambu, Murang’a and Nyeri since the later

two have less degraded environment. Determination of the frequency of other indigenous bees

would compliment studies done elsewhere.

TABLE 7. FLORAL VISITORS TO AVOCADO IN GACHIE VILLAGE, KIAMBU DISTRICT, KENYA

ORDER FAMILY SUBFAMILY GENUS SPECIES

Diptera Calliphoridae Calliphorinae Lucilia sp.

Diptera Sarcophagidae Miltogramminae Hoplacephala tesselata

Diptera Calliphoridae Chrysomyinae Chrysomya chloropyga

Diptera Sarcophagidae Sarcophaginae Sarcophaga inaequalis

Diptera Calliphoridae Calliphorinae Hemigymnochaete varia

Diptera Calliphoridae Rhiniinae Rhyncomya stannocuprea

Diptera Calliphoridae Rhiniinae Rhinia sp.

Diptera Anthomyiidae - Anthomyia sp

Diptera Muscidae Muscinae Musca sp

Diptera Muscidae Phaoniinae Atherigona sp

Diptera Muscidae Coenosiinae Anaphalantus sp.

Diptera Syrphidae Syrphinae Allobaccha sp

Diptera Syrphidae Syrphinae Paragus sp

Diptera Agromyzidae - Melanagromyza sp.

Hymenoptera Apidae Apinae Apis mellifera

Hymenoptera Braconidae Microgasterinae Apanteles sp.

Hymenoptera Formicidae Formicinae Acantholepis sp

page 29

N INITIAL STOCK-TAKING

NUT CROPS

Cashew in Ghana

Peter Kwapong

Cashew (Anacardium occidentale L) is a hardy, drought-resistant tropical or subtropical tree. In the

neotropical zone, it grows from Mexico to Peru and Brazil, including Hawaii, Puerto Rico, and parts

of the southern tip of Florida. Worldwide India is the leading producer: other producing countries

include Mozambique and Tanzania (Mutter and Bigger 1961, Purseglove, 1968).

Even though wild cashew has been growing in various part of Ghana for over ﬁfty years now mainly

for its apple, it is increasingly being cultivated commercially in several areas around the country as an

export crop. Hence cashew has become one of the most important non traditional crops in Ghana.

Research is therefore need to support it successful cultivation especially in the area of pollinators.

The cashew nut is rich in protein and oil and the apple is extremely high in vitamin C (greater than

500% of US-speciﬁed Recommended Daily Allowance) and other minerals. In Ghana the nuts are

processed for export as dried roasted nuts. The apple is consumed fresh as found in many local com-

munities in Ghana or partially dried and candied.

Flowers are tiny, pinkish, borne terminally on panicles. Flowers can be male or hermaphrodite ﬂowers

on the same panicle (inﬂorescence). Both ﬂower types produce pollen and nectar. The cashew fruit is

a 1 inch nut, shaped like a small boxing glove, hanging below a ﬂeshy, swollen peduncle (receptacle)

called the “cashew apple”, which has a value in addition to the nut. (See Figure 11).

Cashew pollination was observed at the Winneba junction in a farmer’s ﬁeld on the same site as

coconut. The plantation covers about 200 acres, part of which has been intercropped with coconut.

The ﬁeld had mixed varieties of cashew, which are not too tall making sampling convenient. Pol-

linators from many different taxa were observed on cashew (Table 8).

There are a variety of potential pollinators on cashew in Ghana. Honey bees, leafcutter bees and

the large carpenter bees offer good

potential for pollinator manage-

ment. However, their efﬁciency as

pollinators needs to be studied and

compared.

FIGURE 11: CASHEW FLOWERS AND YOUNG FRUIT

page 30

ROPS, BROWSE AND POLLINATORS IN AFRICA:

TABLE 8. FLORAL VISITORS TO CASHEW, GHANA

Species observed Score Notes

Honey bee (Apis mellifera) 1 Collecting pollen and are major pollinators

Green metallic bee

(Halictidae) 1 Deﬁnitely pollinators

Megachilidae 1 Deﬁnitely pollinator

Xylocopa sp. 1 Buzz pollinator

Syrphidae 1 Pollinators

Diptera (unidentiﬁed) 1-2 Possible pollinator

Wasps(3) 1-2 Probably nectar and pollen collectors

Calliphoridae 1-2 Walking over ﬂowers causing pollination

Oecophylla longinida (Ant) 1-2 Walking over ﬂowers could result in

pollination

Camponotus 2-3 Probably predators

Muscidae (diptera) 2-3 Probably a pollinator

Coreidae 3 Plant sucking insects

Pyrrhocoridae (cotton stainer) 3 Plant sucking insects

Mantidae 3 Predator

page 31

N INITIAL STOCK-TAKING

OIL CROPS

Coconuts in Ghana

Peter Kwapong

The coconut (Cocos nucifera L.) is found along tropical seashores around the world, and in some

areas it is cultivated far inland. Coconut is described as one of Nature’s greatest gifts to man be-

cause almost every part of the tree is used in some way. Coconut oil, extracted from the dried

endosperm (copra), is unusual amongst plant oils in that it is solid below 24’

C. It was the major

raw material in the production of margarine in the early day of its production. In Ghana, the milk

is usually a refreshing drink for most people. The soft endosperm inside the hard pericarp is a good

source of fat, protein and carbohydrate. The leaﬂets are used for fencing and for raising temporary

sheds. Along most of the ﬁshing coasts, the stems are used to anchor small canoes or ﬁshing boats.

The coconut plant has a tall unbranched trunk surrounded by a crown of fronds, although branched

forms are occasionally found. A leaf requires 10 years to reach full size, then it will last for 2 more years.

A new leaf and an inﬂorescence forms about once each month. The coconut is monoecious, having

both staminate and pistillate ﬂorets on the same many-branched inﬂorescence, the 2- to 4-foot long

spadix or ﬂeshy panicle in the leaf axil. There are only a few female ﬂower on each inﬂorescence and

these are found together with a pair of male ﬂowers at the base of the branches (Figure 12); most of

the male ﬂowers are borne singly or in pairs towards the branch tips. As the ﬂowers contain nectar

and are sweet scented, it is likely that insects are important for pollination. However, as the pollen is

light and dry, there may also be some wind pollination. The male ﬂowers mature and wither before

the female ﬂowers become receptive (a condition known as protandry) so that ﬂowers in the same

inﬂorescence cannot pollinate one another. This ensures cross-pollination. Flowering occurs on the

plant throughout the year.

Coconut pollination was studied in a farmer’s ﬁeld at Winneba junction half way between Cape Coast

and Accra in the Central region of Ghana. It consist of about 20 acres of coconut plantation, in part

intercropped with cashew. Flower visitors and their behaviour on the inﬂorescence are summarized

in the table 9.

Bees appear to be the most impor-

tant pollinators, although this needs

to be conﬁrmed through pollination

efﬁciency experiments and not just

ﬂower visitation. Both honey bees

and stingless bees are social and can

be easily managed in large numbers.

The choice of managed pollinator

should depend on their pollination

efficiency and the farm structure.

Stingless bees are not dangerous like

honey bees and can be safely kept

near farm residences.

FIGURE 12: FEMALE COCONUT FLOWERS

page 32

ROPS, BROWSE AND POLLINATORS IN AFRICA:

TABLE 9. FLORAL VISITORS TO COCONUT, GHANA.

Species observed Score Notes

Honey bee (Apis melifera) 1 Collecting pollen

Stingless bee (Meliponula sp) 1 Many were collected on freshly opened

ﬂowers with pollen on them

Halictidae (Halictus sp) 1 Pollinator

Ants (Campnotus) 2-3 Walking on ﬂowers could result in

pollination

page 33

N INITIAL STOCK-TAKING

Groundnut in Ghana

Peter Kwapong

Groundnut (Arachis hypogea) is an annual plant of the legume family. The edible seeds are called

peanuts. Groundnut is also called goobers, goober peas, earthnuts, monkey-nuts and pinders. They

are native of South America but are cultivated in many parts of the world, chieﬂy in Asia, Africa and

the United States. Groundnut plants differ from other types of leguminous plants by producing

their pods underground.

Groundnut serves principally as human food and livestock feed. The seeds are especially rich in oil

and protein. The roasted seeds can be ground into a paste which makes a delicious spread on bread.

Peanut oil extracted from the seeds can be used for cooking. The whole plant including the seeds

is used as livestock feed. Plants from which seeds have been harvested are fed as hay. Peanut cake,

concentrated food made from seeds that have been crushed to extract oil is also fed to livestock.

Margarine, cheese, a coffee substitute, several kinds of milk, ﬂour, medicine, cosmetics, ink, stains,

dyes, glues, plastics, ﬁbres and insulating boards can be made from peanuts. Manufacturers grind

the shells (pods) into a powder which serves as an ingredient in plastics, cork substitutes, wallboards,

and abrasives. Harvested plants can also be used as organic manure.

Two general types of groundnut (peanuts) are grown commercially all over the world. These are:

bunch or erect (upright) type, which is about two feet high and matures in 3 to 30 months, and the

vine-like runner, creeping or prostrate type, which is about one foot high and branches two feet

long on the ground. This latter type matures after 4 to 5 months and has large seeds. Both types of

plants have thickening stems and small yellow ﬂowers (Figure 13). Generally, ﬂowers are produced

near the ground on bunch plants and along the runners of the vine-like types. Each ﬂower puts out

a sharp stalk called peg. The ﬂower buds open at sunrise. Fertilization takes place during the morn-

ing and the ﬂowers usually wither about noon.

Within a few days the pegs (stalk

stems of the pods) begin to grow.

They grow slowly at ﬁrst, but gradu-

ally grow more rapidly. The peg

enters the ground and the pod

grows from its tip. The tough, ﬁ-

brous pod is about one to two

inches long when matured. In most

commercial varieties, each pod en-

closes two, sometimes three seeds.

Apart from the bunchy and runner

types numerous intermediates exist.

The runner types are more widely

grown in West Africa. In this re-

search the variety that was sampled

was the runner type.

FIGURE 13: GROUNDNUT IN FLOWER WITH

FLOWER BEETLE FEEDING ON PETALS

page 34

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Groundnut pollination was observed in Cape Coast in the Central Region of Ghana, and Northwest

of Accra, the capital city. The area is mainly made up of coastal savannah and groundnut is not a

major crop of the area. However, a few people grow the crop on a very small scale. Insect visitors

to groundnut ﬂowers are recorded in Table 10.

Flower beetles (Decapotoma sp) were found eating petals including stamens as well as styles in some

cases. The ﬂower beetles were seen on peanut ﬂowers as early as 7.50 a.m. Few were found on the

ﬂowers initially but population increased with time especially from 9.00 a.m. onwards when ﬂowers

(keel) began to open. It appears that groundnuts are mainly self-pollinated.

The ﬂower beetles were also found and collected from the ﬂowers of the following plants: Spigelia

sp., Merremia tridentata, Sida acuta, Aspilia africana, Commelina benghalensis, about 500 metres away

from the sampling site.

Leaf beetles were also collected on the plant but were not pollinating. Ladybird beetles were seen

feeding on aphids on the stems. Three bee species belonging to the family Halictidae and an un-

identiﬁed bee were collected from the keel and are probably the main pollinators. Stalk-eyed shoot

ﬂies were also collected, along with two other ﬂy species. Damsel ﬂies were observed on ﬂowers

but are apparently not pollinators.

Halictidae, which are small ground dwelling bees appeared to be the most important pollinators of

groundnut. It will be difﬁcult to increase their population size through management. As it appears as

if bees are the most important pollinators of groundnut, a survey should be carried out in another area

to see if the bees that visit the crop differ, and perhaps more manageable species occur elsewhere.

TABLE 10. FLORAL VISITORS TO GROUNDNUT, GHANA.

Species observed Score Notes

Halictidae (Pseudapis sp) 1 Moved very fast and spent less than 10 seconds

after entering a ﬂower

Halictidae (Lipotriches sp) 1 Deﬁnitely a pollinator

Caliphoridae (dipteran ﬂy) 2-3 Possible pollinator

Flower beetles Meloidae

(Decapotoma sp) 2-3 Eating corolla, stamens and style

page 35

N INITIAL STOCK-TAKING

Oil Palm in Ghana

Peter Kwapong

The oil palm (Elaeis guineensis Jacq. ) is a tree crop believed to originate from West Africa. It is cultivated

in other regions of Africa, in Asia, East and West Indies and South and Central America. In Ghana,

oil palm is grown in six of the ten administrative regions. The oil palm is a high-yielding vegetable

oil crop. It produces oil from the mesocarp of the fruit as well as from the kernel. The uses of oil palm

include manufacture of cooking oil, margarine, soap, cosmetics and other industrial uses. In Ghana,

palm leaves are used for building temporary sheds. Mid-ribs of leaﬂets are put together into brooms.

Leaf stalks are used for weaving baskets. Palm wine is obtained from felled old stems.

Palms may reach a height of 30 meters in high forests; in other areas they are between 15 to 18 me-

ters tall. The oil palm is monoecious; male and female ﬂowers occur separately in male and female

inﬂorescences on the same plant. Occasionally, hermaphrodite ﬂowers occur. An inﬂorescence is a

compound spike held on a stout peduncle. Spikelets are spirally arranged around a central rachis.

Each inﬂorescence contains thousands of ﬂowers.

Oil palm requires adequate pollination to set

fruit. Though both male and female inﬂores-

cences occur on the same plant (Figures 13 and

14), cross-pollination is necessary because the

inﬂorescences on a plant are seldom simulta-

neously receptive.

The study sites for this assessment were oil

palm plantations at Jukwa and Abrafo, both

in the Central Region of Ghana. Observations

were made on both male and female inﬂores-

cences for visiting insects. Some insects were

caught with sweep nets but the structure of

the palm and position of ﬂowers limit the use

of nets. It was more effective to shake the in-

ﬂorescence and collect insects in a receptacle.

Insects so far collected (from male ﬂowers) are

listed in Table 11.

Though these collections were from male

flowers only, the beetles are known from

previous work to that the main pollina-

tors of oil palm. About four species of small

beetles were collected on male inﬂorescence

as major pollinators. Three bee species and

FIGURE 15: MALE INFLORESCENCE,

IL PALM

FIGURE 14: FEMALE INFLORESCENCE,

IL PALM

page 36

ROPS, BROWSE AND POLLINATORS IN AFRICA:

one wasps species were also collected. All the bees as well as the wasps had pollen on their bod-

ies but their role in pollination is unconﬁrmed, as they are not known to visit female inﬂorescence.

Further work is required to correctly identify all pollinators and ensure their conservation. Being

indigenous to West Africa, the origin of the oil palm, their conservation is in the interest of the oil

palm and palm oil industries world wide.

TABLE 11. FLORAL VISITORS ON OIL PALM, GHANA.

Species observed Score Notes

Oil palm weevils (Curculionidae) 1 Main pollinators (100s of them)

Nitudilidae 1 Pollinator

Honey bee 2-3 Many bees collecting pollen

Megachilidae 2-3 Few with pollen under abdomen

Halictidae 2-3 Few to many collecting pollen

Thrips 2-3 Probably pollination

Wasps 2-3 Collecting pollen

page 37

N INITIAL STOCK-TAKING

BROWSE

Acacia pods in Kenya

Dino Martins

The Umbrella thorn (Acacia tortilis) is a spiny acacia (Mimosoideae), usually a shrub to a large

spreading tree in Kenya. It is among the most drought resistant acacia species and grows with

200-900mm of rainfall. Its pollination was observed primarily in the Kerio Valley, Northwest-

ern Kenya, where these trees are typically large and spreading forming extensive woodlands.

The trees’ branches are armed at each node with a straight white thorn as well as two short

grey sharply recurved spines, and the small leaves are closely spaced, making the tree densely

leafy. Umbrella thorn ﬂowers are in white, cream or sometimes pale yellow capitate heads.

Acacia tortilis is in many ways a tree of high, and sometimes unrecognised potential. Products

are derived that directly or indirectly contribute to pastoral communities’ livelihoods and survival

in times of extreme drought. The main use in the Kerio valley is collection of pods for livestock

fodder. These are additionally transported out of the valley and into the adjacent highlands

where they are sold to people with livestock as a supplement food for goats, sheep and cattle.

Ripe fresh pods are eaten but the seeds are normally discarded, except in times of extreme food short-

age. Then seeds are eaten as well. The crunchy pods have a faint sweet taste. Besides the pods the

gum can also be eaten but is of inferior quality, is sticky and may cause choking. It is a typical famine

food and a last resource in Somali Region of Ethiopia where it is collected by children and women

when other foodstuff gets scarce. Pods are col-

lected and eaten by peoples inhabiting the Kerio

valley and Lake Turkana Basin of Kenya, as well

as throughout the Samburu and North-eastern

districts. When rains fail or are insufﬁcient for a

number of other wild foodstuffs to grow, seed-

pods from A. tortilis are a secure food than can

be picked at the end of a severe drought period.

Furthermore, the inner bark can be chewed to

relieve thirst and the bark is also used medicinally.

The main use of the seedpods from this acacia as

a supplementary feed/nutritional supplement to

livestock- primarily goats, sheep and cattle. This

is where effective pollination is crucial. Hundreds

of Keiyo and Pokot women (mostly) throughout

the western and central areas of the Kerio Valley

gather the pods when ripe/semi-ripe. The pods

are shaken from the tree using a long notched

stick. In some cases young boys climb half-way

into the tree and aid in dislodging the pods. The

pods are then collected by hand from the ground

and packed

IGURE 17: ACACIA FLOWERS

FIGURE 16: PERCENTAGE TYPES OF FLORAL

ISTORS TO ACACIA TORTILIS, KERIO VALLEY

page 38

ROPS, BROWSE AND POLLINATORS IN AFRICA:

into sacks. These are trans-

ported by donkey or on lorries

to the town centres of Biretwo

and Iten, where they are sold.

The price per sack of acacia

pods ranges from 100-200

Kshs ($ 1.3 – 2.6). Most of

the pods end up being fed to

livestock in the adjacent high-

lands, where heavy rainfall

has resulted in leached soils

and consequently mineral-

deﬁcient grazing and browse. Pods, once dry, can be stored in sacks for many months, and are fed

to livestock in handfuls each day.

Herders and household with large numbers of livestock will also drive the stock under certain tree

that are heavily-laden with pods and then shake the tree to loosen the pods for the animals to eat.

The two main periods of pod harvest are a couple of months

after each rainy season (ﬂowering) mainly in July-August and

December-January.

The inner wood of dead trees oozes a dark sap that is used by

the Borana peoples of northern Kenya as a source of perfume.

The wood is crumbly and highly aromatic with a spicy-sweet

scent. It is harvested and widely traded in markets throughout

the region. The local name for the perfume from Acacia tortilis

is “Foras”.

Fuel wood and charcoal prepared from this species are widely

sold on local markets and along commercial tracks throughout

Kenya and in the Somali Region. The charcoal from this and

other acacia species is in high demand and considered of the

highest quality for roasting meat.

Umbrella thorn pollination was investigated in the Kerio Valley,

Northwestern Kenya, East Africa, with additional observations

made in the southern Great Rift Valley, near Olorgesailie.

The ﬂowers of umbrella thorn are borne singly or in small axil-

lary groups distributed on all the outer branchlets and twigs

(Figure 16). They ﬂowers are capitate (spherical) and gener-

ally off-white or pale ivory in colour. As with many species

of acacias, pollen dehiscence is controlled by the tree, with a

distinctive peak in dehiscence that corresponds to a peak in

ﬂoral visitors and consequently pollinator activity.

TABLE 12. RANKING OF EFFECTIVENESS- ACACIA VISITORS.

Group under consideration Score

Native bee/wild bee species 1

Honeybees- Apis mellifera 1

Syrphid ﬂies 2

Butterﬂies, moths (and Microlepidoptera) 2

Wasps 2-3

Ants 3

Beetles 3

FIGURE 19: PERCENTAGE TYPES OF

LORAL VISTORS TO ACACIA TORTILIS,

ATURAL VEGETATION SITE

FIGURE 18: PERCENTAGE TYPES OF

LORAL VISTORS TO ACACIA TORTILIS,

LOSE TO BOMAS

page 39

N INITIAL STOCK-TAKING

In the Kerio Valley, the ﬂowers were observed to begin to open after sunrise. Pollen dehiscence began

around 11.00 a.m. and peaked later between noon and 2.00 p.m. This period of dehiscence is later

that observed further south in Mkomazi, Tanzania, where trees peak dehiscence between 7.30 a.m.

and 9.00 a.m. (Stone et al. 1996).

Individual capitate ﬂowers actually consist of many tiny ﬂowers, densely packed to form the spherical

blossom. The anthers are arranged in a thick bunch, radiating outward from the ﬂoral cup. Stigmas

vary in number and are also variable in protandry and distribution within and across ﬂowering trees.

Nectar was assumed to be present, given the presence of large numbers of nectarivores, including

butterﬂies and sunbirds, that were seen actually feeding from ﬂowers. Some captured lycaenids

squirted droplets of moisture and this was also taken as an indication that the ﬂowers contained

some amounts of nectar.

The capitate ﬂowers are easily accessed by a large number of animals, primarily insects. Most insects

land on the ﬂowers directly and move around from ﬂower to ﬂower once on a ﬂowering tree. This

movement and behaviour, as well as the morphology of the potential pollinators, are the primary

factors used in assessing pollination in this species. Following is an analysis of the ﬂoral visitors, in

terms of diversity, trends, patterns and their efﬁcacy as pollinators.

A wide range of insect species are visitors to Acacia tortilis. Floral visitors include species of bees, ants,

wasps, butterﬂies, moths, sunbirds and beetles (Figure 17). From this chart, it can be seen that Wild

bees (native bee species other than honeybees) form the bulk of visitors to this acacia. Native bees

account for 61 % of the total visits to Acacia tortilis when compared directly against the numbers

and frequency of all other insect visitor taxa.

Insect ﬂoral visitors were also observed at length at another site, the southern portion of the Great

Rift Valley, near Olorgesailie. Here, as in the Kerio Valley, A. tortilis forms an important part of the

woody vegetation. Trees at two distinct sites were studied. One located adjacent to a pastoralist

homestead (boma), where most of the natural vegetation other than the individual Acacia trees had

been removed. The ground cover was mostly eaten by the livestock and most of the ground was

bare and rocky. The second site where pollination observations were carried out on this species was

located in an area relatively undisturbed and with many other species of plants in ﬂower. A distinct

difference was noted in the ﬂoral visitors between the two sites, as illustrated in Figures 18 and 19.

The site with lots of natural vegetation, in particular other ﬂowering plants, had far more diversity

of native bees, than the site where most other natural vegetation had been removed.

Based on the criteria developed for scoring insect visitors as pollinators, careful observations of each

major group, across all sites, yielded the scores recorded in table 12. For the most part, wild bee

species were seen to spend the longest time on the tree’s ﬂowers and moved among inﬂorescences

and between ﬂowering trees. Native bee species were also found to carry the most pollen on their

bodies, where it was available for pollination.

Butterﬂies and honeybees also spent time on ﬂowers and their pollen loads were seen brushing ﬂoral

parts. It is important to note that most butterﬂies studied, mainly lycaenids (which form

page 40

ROPS, BROWSE AND POLLINATORS IN AFRICA:

TABLE 13. FLORAL VISITORS TO ACACIA TORTILIS BLOSSOMS, KENYA

Floral visitor group Observations/behaviour

ANTS:

Camponotus sp. Seen patrolling branches, scavenging

opportunistically, occasionally see on ﬂowers

Crematogaster sp. Many thousands of this genus seen on some

trees, no major ﬂower visitation observed.

Technomyrmex sp. Large numbers of this species seen

periodically in disturbed sites, seen attacking

other insects on tree.

BEETLES:

Buprestidae: Sternocera orissa Small groups of these large beetles were

seen feeding amongst ﬂowers, pollen

transported on ventral surface of abdomen.

Cerambycidae: Promeces sp. Seen perched on ﬂowers.

Scarabaeidae: Rose chafers- Pachnoda spp. Feeding on ﬂowers, little pollen observed on

bodies

Scarabaeidae: Rose chafers-Rhabdotis sp. Feeding on ﬂowers, little pollen observed on

bodies

Scarabaeidae: Rose chafers-Cyrtothyrea sp. Feeding on ﬂowers, little pollen observed on

bodies

Lycidae: Lycusspp. Feeding on ﬂowers, little pollen observed to

be carried.

FLIES:

Asilidae: robber ﬂies Perch on branches and hunt ﬂoral visitors

Bombyliidae: bee ﬂiesNotolomatia sp. Common ﬂoral visitors, some pollen present.

Syrphidae:Phytomia sp. Very common at some sites. Tend to visit

trees before pollen dehiscence begins.

Limited pollen transport.

Syrphidae:Allograpta sp. Very common at some sites. Tend to visit

trees before pollen dehiscence begins.

Limited pollen transport.

Syrphidae:Eristalis sp. Very common at some sites. Tend to visit

trees before pollen dehiscence begins.

Limited pollen transport.

Milichiidae: Jackal ﬂies Seen scavenging near crab (ﬂower)

spiders with prey.

Calliphoridae:Chrysomya sp. Visiting ﬂowers, common in areas near

homesteads, no signiﬁcant pollen transport.

BUTTERFLIES AND MOTHS:

Scythrididae: ﬂower moths Common on ﬂowers, diurnal moths, little

pollen transport

Sphingidae: Hawkmoths Fairly common visitors, hover while feeding

Macroglossum sp.Cephonodes sp. so little opportunity of collecting pollen on

body from capitate ﬂowers.

Ctenuchidae: handmaidens Seen visiting ﬂowers, stay high in trees

Agaristidae:Utetheisa sp. Occasionally observed on ﬂowers

continued..

page 41

N INITIAL STOCK-TAKING

TABLE 13. BEHAVIOUR OF FLORAL VISITORS ON ACACIA TORTILIS BLOSSOMS, CONTINUED

Floral visitor group Observations/behaviour

Hesperiidae : skippersSpialia sp.Coeliades sp. Active feeders, moving around, heavy-bodied

and seen to carry a little pollen.

Nymphalidae:Danaus chrysippus, All fairly common, some pollen transport.

Junonia oenone, Junonia hierta

Hamanumida daedulus,Hypolimnas misippus,

Byblia ilythia

Lycaenidae: Azanus spp. Very common at some sites, feeding at ﬂowers.

Larvae recorded on Acacia leaves. Adults also

roost on acacias. Little pollen transport evident.

Lycaenidae: Cacyreus spp. Common on ﬂowering trees. Little pollen

transport evident.

WASPS:

Chalcididae:Hockeria sp. Parasitic wasps, occasional visitors to acacia

ﬂowers, more common amongst surrounding

herbaceous ﬂora

Scoliidae Common, patrolling underneath ﬂowering trees

Chrysididae Regular visitors to ﬂowers. Little pollen seen on

bodies.

Tiphiidae Common, patrolling underneath ﬂowering trees

Pompilidae:Cyphononyx sp.Hemipepsis sp. Regular and noticeable visitors, more common at

trees in Rift near bomas.

Vespidae:Polistes spp. Very common ﬂoral visitors, little pollen

movement.

Eumenidae:Anterhynchium sp.Delta spp. Regular ﬂoral visitors, hunt on and around

ﬂowering trees.

Sphecidae:Ammophila spp. Common ﬂoral visitors, seen hunting on tree,

little pollen transport. Moves rapidly amongst

ﬂowers, barely stopping.

BEES:

Apidae:Xylocopa somalica, X. inconstans, Common visitors to ﬂowers. Transport of large

X. nigrita, X. caffra pollen loads (amongst the largest recorded),

move large distances between trees.

Apidae:Hypotrigona spp. Very abundant visitors at some sites. Spend long

time on ﬂowers, good pollen loads.

Megachilidae:Megachile spp. Very common ﬂoral visitors, move systematically

and thoroughly over open ﬂowers. Pollen loads

large.

Apidae:Amegilla spp.Anthophora spp. Regular visitors to ﬂowers, good pollen

transporters

Thyreus sp. Regular ﬂoral visitor, some pollen observed.

Allodapula spp. Abundant, spend time on ﬂowers, carry pollen.

Apidae:Ceratina sp. Common visitors to ﬂowers. Pollen transport

clearly evident.

Braunsapis sp. Common ﬂoral visitors. Spend time crawling over

ﬂowers. Pollen transport evident.

continued.

page 42

ROPS, BROWSE AND POLLINATORS IN AFRICA:

the bulk of lepidopteran ﬂoral visitors), actually carried miniscule amounts of pollen. Syrphid ﬂies

carried little pollen, but did spend time moving about the ﬂowers.

Wasps varied in number and diversity from site to site, but included both solitary and social species.

Some wasps spent more time on the ﬂowers than others. Many wasps were opportunistic visitors

to the ﬂowering trees, seeking both nectar and preying on other insects. Ants and beetles were the

least effective ﬂoral visitors based on the criteria of pollen loads and movement. Many beetles simple

ate the ﬂowers, despoiling them for other potential pollinators. Only large buprestids were found to

carry much pollen, but these tended to stay on a single tree for a long time.

Table 13 summarises the diversity of ﬂoral visitors to Acacia tortilis and notes on their behaviour and

efﬁcacy as pollinators.

Native bees species, analysed in terms of behaviour, pollen loads, pollen movement and abundance

and distribution are the primary pollinators of Acacia tortilis at all sites studied. Native bee diversity

is directly proportional to pollination success on this species. Much more work needs to be done

on bee diversity in relation to seed set and pollination on acacias. It is unlikely that technologically

advanced pollination will be managed for Acacia tortilis because a food source for stock during

particularly drought periods for poor farmers. However, most of the important pollinators nest in

dead wood, making room for low-tech pollination management in that farmers that depend on this

resource should not denude the areas of dead wood.

TABLE 13. BEHAVIOUR OF FLORAL VISITORS ON ACACIA TORTILIS BLOSSOMS, CONTINUED

Floral visitor group Observations/behaviour

Apis mellifera Common ﬂoral visitor in some sites, often does

not visit during peak pollen dehiscence due to

temperature constraints. Good pollen transport

when present.

Tetraloniella spp. Occasional visitors, good pollen transport.

Macrogalea candida One of the most abundant native bee visitor

species, good pollen loads. Spends time on

ﬂowers.

Halictidae:Nomia spp. Common ﬂoral visitors, transport large

amounts of pollen.

Lipotriches sp. Common ﬂoral visitors, transport of pollen

evident.

Pseudapis sp. Common ﬂoral visitors, often seen rising into

air from ﬂowers to comb pollen from body.

Lasioglossum sp. Common ﬂoral visitors at some sites. Good

pollen transport.

page 43

N INITIAL STOCK-TAKING

Indigofera (Dwarf Rangeland Browse Shrubs) in Kenya

Barbara Gemmill-Herren

In arid and semi-arid ecosystems, grasses dominate the herbaceous layer, but particularly on sites

with deeper soils other forage is important. On sites with good soils about 7 kg/ha/y of forage may

be produced for each mm of rainfall. In the dry season, browse that is high in protein forms a criti-

cal part of the diet for both livestock and wildlife. Dwarf shrubs form a large part of the browse in

livestock and wildlife diet. Among the most important of dwarf shrubs in this Kenyan rangeland

ecosystem are the Indigoferas: Indigofera spinosa, Indigofera volkensii, and Indigofera cliffordiana among

others, and Barleria.

In the north of Kenya, studies tracing the human food obtained as livestock products back to the plant

community responsible for their production reveals the importance of browse in this system. Dwarf

shrubs, particularly Indigofera spinosa, were the most important component of the plant community,

being ultimately responsible for 43% of the energy consumed by humans (Swift, Coughenour and

Atsedu 1996).

The responses of shrubs to grazing have been less studied than that of grasses. Work in south Turkana

on Indigofera spinosa, however, reports that at even fairly high levels of herbivore removal, no depres-

sion in aboveground production or nitrogen yield was found. This is not to suggest that rangeland can

be continuously overgrazed. Many of the dwarf shrubs, such as Indigofera and Barleria, are short-lived

perennials which means that their persistence depends

on successful reproduction. Since neither reproduces

vegetatively, their reproduction depends on effective

pollination and reproduction by seed.

Some information is known about the pollination of

species within the genus Indigofera, not because of its

browse value, but because some species are cultivated

as a source of indigo dye: Indigofera arrecta A. Rich, and

Indigofera tinctoria L. var. tinctoria. In both species, the

ﬂowers are bisexual and seed is set only if visited by bees.

Extensive cross-pollination seems to result in better seed

set (Howard and Howard 1915, Howard et al. 1919).

Indigofera (Figure 20) is a species that may rapidly build

up to dominate the understory of arid woodlands, such

as the Tsavo ecosystem, in years following heavy rainfall.

In the year after the heavy rains of La Niña in Kenya

(1998), people working on Rukinga Ranch remember

vast hectares of Commiphora woodland turned pink with

Indigofera blossoms under the tree canopies.

FIGURE 20: INDIGOFERA BLOSSOMS

FIGURE 21: STINGLESS BEE NEST ENTRY TUBE

page 44

ROPS, BROWSE AND POLLINATORS IN AFRICA:

It is interesting to inquire how a spe-

cies, dependent of bees for seed set

and seed set for dispersal, can build

up so quickly under favorable condi-

tions; in particular, the pollination

community must somehow manage

to cover the resource adequately for

this to occur.

Dwarf shrub species of the genus

Indigofera have been observed at

Mpala Research Center in the Lai-

kipia Plateau of Kenya; an area of

great importance both to livestock

production and wildlife populations.

Indigofera was also observed on

Rukinga Ranch, Taita District, which

forms a critical wildlife migration

corridor between the Tsavo East and

Tsavo West. Ranches in this area are

used for fattening cattle brought from Somalia for sale in Nairobi, and thus the graze resource is of

high economic importance.

Non-Apis bees make up the vast majority of visitors. All visitors appeared to handle the ﬂowers

properly and should be considered pollinators (Table 14)

One population of stingless bees that visited Indigofera ﬂowers in Rukinga were found nesting in

a tree next to the patches of ﬂowers (Figure 21).

The average number of ﬂowers visited by pollinators to Indigofera, per 10-minute observations period

was about half a ﬂower, due to the many observation periods with no visitors. The overall visitation

rate for Indigofera is far lower than mass ﬂowering species such as Acacia, or densely ﬂowering crops

such as coffee. Visitation rates were not strongly affected by the number of ﬂowers in a patch; in

fact higher average visitation rates occurred on patches of 10 ﬂowers or less, than for patches of 10

ﬂowers or more. While this correlation is not strong, it does indicate that Indigofera is not a ﬂower

that attracts masses of generalized pollinators over short periods of time. The indigofera ﬂowers are

not strongly scented and must be tripped by an insect, and are therefore more likely to be attractive

to specialized pollinators that know how to “work” the ﬂower.

The successful reproduction of Indigofera, with its dependence upon pollinators, highlights the

critical but unseen ways in which pollination underpins ecosystem health. The importance of dwarf

shrubs such as Indigofera ripple throughout the ecosystem, ﬁxing nitrogen to improve soil fertility

and providing important browse to livestock and thus food security for people, as well as browse

and cover for wildlife in savanna ecology.

TABLE 14: FLORAL VISITORS TO INDIGOFERA SPP. ON MPALA AND

UKINGA RANCHES, AND ALSO NEAR MURANGA, SOUTH OF SAGANA

WERE:

Family Genus and species

Halictidae Nomia theryi

Lipotriches sp. 3

Lipotriches sp. 4

Lipotriches sp. 6

Lipotriches sp. 7

Pseudapis sp.1

Nomia sp.

Megachilidae Heriades sp.

Pachyanthidium sp.

Apidae Ceratina sp.

Hypotrigona sp.

Liotrigona sp.

page 45

N INITIAL STOCK-TAKING

This small sample of Indigofera pollinators highlights the importance of non-Apis bees. The diversity,

particularly of halictid bees visiting Indigofera ﬂowers is striking; taxonomic experts think there may

be new species amongst those gathered in this preliminary assessment. The ability of rather special-

ized bees such as the Lipotriches to presumably build up in number during seasons of high rainfall

to provide sufﬁcient pollination services to Indigofera so that the shrub can vastly expand its cover

remains an interesting puzzle, and one whose answer might help us to understand the resilience of

arid ecosystems. Lipotriches have been thought, at one time, to be rather specialized on harvesting

grass pollen (Immelmann and Eardley 2000), but further observations are ﬁnding that Lipotriches

species exploit a wide range of ﬂoral resources, including crops such as watermelon and groundnut.

What we do not know until more taxonomic work can be done on Lipotriches is how specialised

each individual species is on particular ﬂoral resources.

A variety of bees visit Indigofera. Their nesting habits include social nests in cavities, solitary nests

in hollow sticks and wood borer burrows in wood, and burrows in the ground. Effective pollination

management for an indigenous shrub species such as Indigofera involves maintaining a healthy,

natural ecosystem.

page 46

ROPS, BROWSE AND POLLINATORS IN AFRICA:

FIGURE 22: HONEYBEES ON COFFEE

FIGURE 23: BAGGED COFFEE INFLORESCENCES

FIGURE 24: COFFEE PLANTATION AND RIPARIAN

OREST, WITH WILD HONEYBEE HIVES

Coffee is by far the most important cash crop

throughout eastern and central Africa. It is a

commodity that provides the major source

of foreign exchange for many countries in

the region, and supports the livelihoods of

millions of smallholder farm families. More

than 80% of the coffee produced in East Af-

rica is produced by an estimated 10 million

smallholder coffee farmers. In Kenya alone,

18,000,000 farm families rely on coffee for

income, and the coffee produced amounts

to 140 million USD.

Despite its economic importance to the

region, coffee production in the region is de-

clining, from a high of 8 million bags in 1983

to the current average of 6 million bags per

year, amounting to less than 6 percent of the

global coffee market. A major factor in this

decline is the abolition of economic clauses

of the International Coffee Agreement (ICA)

and the consequent collapse in prices lead-

ing to reduced husbandry; although other

contributing factors include social, economic

and political issues. In many places, the prices

now received by growers are insufficient

even to enable them to maintain the trees.

There is a renewed interest in the region,

however, for the development of specialty

coffee markets, to obtain premium prices for

excellent quality coffee from the region, for

organically and fair-trade produced coffee,

and for biodiversity-friendly coffee grown

under shade trees.

The question of whether bees are important

for coffee production has been fairly well

resolved by recent research.

BEVERAGE CROPS

Coffee in Kenya

Wanja Kinuthia, Laban Njoroge, and

Barbara Gemmill-Herren

page 47

N INITIAL STOCK-TAKING

Traditionally, coffee was considered to be self-

pollinating, but recent research in both Costa

Rica (Roubik 2002) and in Indonesia (Klein et

al. 2003) have shown conclusively that animal

pollination contributes substantially to coffee

yields. In Costa Rica, two varieties showed over

25% fruit retention increases from pollinating

visits by bees. In one variety, coffee berries were

over 25% heavier and developed faster from

open pollination. The yield beneﬁt from open

pollination, chieﬂy by feral African bees, was

56%. In Indonesia, self pollination accounted for

only 10- 60% of the yields obtainable by open or

deliberate cross-pollination. In Costa Rica, feral

Africanised honey bees were the principal pol-

linators of coffee, making it all the more ironic

that coffee pollination has not been studied in

the centre of origin of the crop (Ethiopia-Ke-

nya). Up until the present, pollination has not

been a subject of research at institutes such as

the Coffee Research Foundation in Kenya.

Coffee ﬂowers were observed in Sasini, Twin

Rivers Farm in the Yatta region, and the Cof-

fee Research Foundation in Riuru, Kabete,

and Thika. On both of the farms in Yatta

region where information was collected on

pollination, honey bees were by far the most

numerous and thus important of pollinators for both coffee and for watermelon. Yet, the coffee

estate where observations were made does not keep bees, out of fear that the honey will be stolen.

Thus farmers in the region are relying on wild bee colonies, of which there are several. On the cof-

fee estate, bees had formed a nest in the thicket of grasses and woody plants where the land was

too swampy to farm, and also had established nests high up in riparian trees near the river. (Figure

24). One of these nests had just been attacked by a honey badger, attesting to the high on-farm

biodiversity in the area (along with buffalo said to live in the swamp).

Unfortunately, the owner of one coffee whera pollination observations were carried out was de-

termined to plant as much acreage as possible to coffee, and had labourers removing all riparian

vegetation on several streams, right to the edge of the water- in contravention to Kenyan land-use

law. It is unlikely that the farm would be managed in this way if the land managers understood the

importance of wild spaces on farm, as nesting sites for pollinators.

Another potential source of pollinators, both honeybee and non-honeybee, is the few protected

areas in the region. In this intensely cultivated region, protected areas tend to be rocky, low fertility

inselbergs or outcroppings.

IGURE 25: PERCENTAGE TYPES OF FLORAL

ISITORS TO COFFEE OVER TOTAL OBSERVATION

PERIOD OF 18.2 HOURS, MULTIPLE SITES, KENYA

FIGURE 26: AVERAGE NUMBER OF FLOWERS

VISITED BY TAXA, OVER 10-MINUTE PERIODS

page 48

ROPS, BROWSE AND POLLINATORS IN AFRICA:

While these have generally been

considered too weedy to be treated

as forest reserves, and of little or no

agricultural value, they often have a

rich and diverse ﬂora of outstanding

botanical interest. Two have been

protected in the region. About 10

kilometres away in one direction is

ol’ Donyo Sabuk, a massive inselberg

managed by Kenya Wildlife Ser-

vices. The lower slopes of the hill are

dominated by Acacia bushland and

thicket. The upper forest is a rem-

nant of a once-common montane

forest type dominated by African

Olive (Olea), Podo (Podocarpus), Fig

trees (Ficus) and Croton. About 10

kilometres in another direction is

the Mutomo Hill Plant Sanctuary,

gazetteted as a plant sanctuary in

the 1950s by the National Museum

of Kenya. Interestingly, Mutomo was identiﬁed as an important botanical area by the well-known

Swiss botanist Peter Bally, and was the ﬁrst plant, as opposed to wildlife sanctuary established in

Africa. While it is unlikely that pollinators visiting the coffee and watermelon that we observed in

the region came directly from these reserves, their presence in this largely agricultural landscape

may be providing sources of populations of pollinators to establish in agricultural ﬁelds (even if they

will often be exterminated due to soil disturbance or use of pesticides).

Even more interesting to on-farm biodiversity, however, is the previous practice, almost non-existant

in Kenya today, to grow coffee under shade trees. Historically, two indigenous species were used

in Kenya for shade-grown coffee: Erthrynia (the famous “Flame Trees of Thika” and Croton. Both of

these species are highly attractive to pollinators, as well as to birds and other taxa. The Coffee Re-

search Foundation of Kenya is interested in re-introducing research on shade-grown coffee, which

may have sustainability beneﬁts that sun coffee cannot provide. Including a pollination component

in such comparative research would be a valuable addition.

Coffea arabica, the most common coffee species in this region, has ﬂowers in groups of 2-20 in the

axils of the leaves. The stigma is receptive when a ﬂower opens at dawn, and ﬂowers are usually pol-

linated within two hours after opening. Flowers wither within 48 hours after opening if pollinated,

but persist for much longer if not visited by insects.

Coffee ﬂowers were visited by primarily by honey bees, ﬂies, and other bees, with butterﬂies,

wasps and beetles making up an insigniﬁcant contribution (Figure 25). The average number of

ﬂowers visited by each of these groups, per 10-minute observations period is given in Figure 26.

TABLE 15. FLORAL VISITORS TO COFFEE, KENYA

Family Genus and species

Collectidae Hylaeus (Nothylaeus) sp.

Hylaeus (Deranchylaeus) sp.

Halictidae Lasioglossum (Dialictus sp.)

Sphecodes sp.

Lipotriches sp.

Halictus (Seladonia) sp.

Pseudapis sp.

Apidae Braunsapis fascialis (Gerstaecker)

Braunsapis rolini (Vachal)

Braunsapis trochanterata (Gerstaecker)

Braunsapis sp.

Amegilla atrocincta (Lepeletier)

Amegilla acraensis (fabricius)

Ceratina (Ctenoceratina)

Ceratina sp.

Xylocopa inconstans (Smith)

Apis mellifera (L.)

page 49

N INITIAL STOCK-TAKING

Although ants rapidly scurried over ﬂowers and did visit a considerable number of ﬂowers per ten

minute period, they were infrequent, and did not appear to approaching the ﬂowers in ways that

ensure proper pollination. Thus, honey bees, ﬂies and other bees were observed as the most effective

pollinators (Figures 22, and 26).

Particularly numerous, among the non-Apis bee, were Lasioglossum (Dialictus sp.) and the two Bra-

unsapis species, Braunsapis fascialis and Braunsapis rolini.

TABLE 16. INSECTS BESIDES BEES VISITING COFFEE INCLUDED:

Order Family Sub-family Genus Species

Coleoptera Bruchidae Amblycerinae Spermophogus sp

Diptera Syrphidae Milesiinae Eristaliaus quinqualineatus

Diptera Syrphidae Syrphinae Allograpta Nasuta

Diptera Syrphidae Syrphinae Betasyrphus sp.

Diptera Syrphidae Milesiinae Phytomia incisa

Diptera Syrphidae Milesiinae Eristalinus sp.

Diptera Muscidae Phaoninae Atherigona sp.

Diptera Muscidae Muscinae Orthellia sp.

Diptera Conopidae - - -

Diptera Calliphoridae Chrysomyinae Chrysomyia sp.

Diptera Calliphoridae Rhiniinae Stomorhina rugosa

Diptera Calliphoridae Rhiniinae Stegosoma sp.

Diptera Calliphoridae Rhiniinae Isomyia sp.

Diptera Calliphoridae Rhiniinae Rhinia apicalis

Diptera Tipulidae - - -

Diptera Lauxaniidae Lauxaniinae Lauxania sp.

Diptera Lauxaniidae - Pahcycerina sp.

Diptera Agromizidae - - -

Diptera Sciaridae - Apeimocrengris sp.

Hemiptera Pyrrhocoridae - Dycercus sp.

Hymenoptera Formicidae Formicinae Polyrhachis sp.

Lepidoptera Heliodinidae - Eretmocera sp.

Lepidoptera Sphingidae - Cephonodes sp.

Lepidoptera Pieridae - Catopsilia ﬂorella

Lepidoptera Papilionidae - Papilio demodocus

Lepidoptera Lycaenidae - Leptptes pirithous

Lepidoptera Lycaenidae - Cupidesthes arescopa

Lepidoptera Nymphalidae - Hypolimnus misippus

page 50

ROPS, BROWSE AND POLLINATORS IN AFRICA:

It is interesting to see how pollinators cover the ﬂowering resources as coffee trees enter their peak

ﬂowering period. When ﬂowers are less abundant, at the beginning of the ﬂowering season, a typical

number of ﬂowers per meter square might be 100 ﬂowers. Over any ten-minute period, an average

of twenty may be visited, thus 20%. During peak ﬂowering, of around 3000 ﬂowers per meter square,

the total number of ﬂowers visited rises to 40, but the percentage coverage falls dramatically to 1%.

It is likely that the pollination community cannot saturate the ﬂowering resources, at peak ﬂowering

times- at least in these farms where there is no deliberate effort to enhance pollinator presence by

keeping hives of honeybees.

To determine the effectiveness of a single pollinator visit on coffee, which can self-pollinate, forty-six

coffee ﬂowers were bagged so that no visitation could occur, and the bags removed to allow a single visit

of one honeybee to one ﬂower. (Figure 23). The stigma of this ﬂower was then excised, prepared on a

slide and examined under a microscope to count pollen deposited. An equal number of open-pollinated

ﬂowers, experiencing unlimited pollination visits, and a small number of control ﬂowers, bagged so as to

experience no animal pollinator visits (except possibly ants which might have been able to manoeuvre

into the net bags) were examined in the same way. Open pollinated ﬂowers had about twice as many

pollen grains deposited on stigmas, as opposed to those ﬂowers experiencing no visits or only one visit.

The importance of insect visitation is apparent, but needs to deﬁnitively determine pollinator ef-

fectiveness, (as opposed to the rapid assessment conducted here) it is necessary to follow berry

development from pollination through to actual yield. Another interesting research question, posed

by Dr. David Roubik on the basis of his work on coffee pollination in Costa Rica, is whether pol-

lination may not only contribute to yield, but also to quality. He suggests (D. Roubik, pers. Comm..)

that ﬂowers able to widely out-cross (by being visited by far-ﬂying pollinators) may have improved

coffee ﬂavour. As coffee production and research is turning increasingly to questions of quality (and

the premium prices paid for quality), this is also an important research question for the future, to be

answered through a longer-term study that follows pollination through to harvest.

Coffee pollination in its center of origin- Eastern Africa- is a neglected subject that can contribute

substantially to coffee yields and possibly quality. Even without managing pollinators, we found

that farmers in this agricultural area were still beneﬁting from pollinators that nest in adjacent wild

habitat. Yet this wild habitat is being cleared rapidly as farmers seek to expand their agricultural area.

If coffee quality might be enhanced by having more pollinators, the farmers’ (erroneous) perceived

reduction in yield from not clearing bee-nesting habitat on farm might be made up in actual in-

creases in both yield and quality. Since the coffee tree builds up to peaks of mass ﬂowering, means

of conserving pollinators on-farm could have value in assuring that the pollinator community can

build up to meet peak ﬂowering periods.

Around the world coffee is principally self and bee pollinated (Roubik 2002 and Klein et. al. 2003.)

and Kenya is no exception. Honey bees are the principal pollinators, and much technology exists to

manage honey bees. Of the other bees there are soil nesting and above ground nesting bees. These

will both occur in natural areas, and certain practices can increase their numbers, like leaving dry

wood in place and clearing parts of the ground.

page 51

N INITIAL STOCK-TAKING

Summary and Conclusions

Most countries wishing to start a pollinator conservation program will be faced with the

challenge of assessing the role of pollinators, and knowledge on these roles, in their coun-

try. Working out the complete pollination biology of a specific crop is multi-year study,

but if pollinators are indeed being lost as agricultural development proceeds, most coun-

tries and regions will have neither the time nor resources to study each crop in depth.

As a contribution to the International Pollinator Initiative, the Food and Agriculture Organization of

the United Nations invited national partners in Ghana, Kenya and South Africa to undertake a rapid

assessment of pollination systems important to crop production in each respective country. Within the

scope of time and resources, it was possible to identify and rank the important pollinators for a range

of crops, and to identify threats and barriers to pollinator conservation in the different agroecosystems.

Farmers’ knowledge of pollination in both Kenya and Ghana was found to be widely variable, from

farmers who understood the role of pollination in seed set, to farmers who believe that bees are harm-

ful and need to be killed. Extension agents in Ghana has somewhat better knowledge of pollination

services, but did not seem to be actively passing this on to farmers. Researchers and civil society or-

ganisations tended to focus on beekeeping as a source of sustainable livelihoods, and were not directly

concerned with the conservation of pollination services. The published literature on pollination of

crops important in Africa is not small, but few of the studies have been carried out in an African context.

Methodologies are presented here that are easily replicable for a rapid assessment of the impor-

tant pollinators visiting pollinator-dependent crops. It should be noted that in a rapid assess-

ment, it is not possible to conclusively determine degree of dependence on pollinators and which

pollinators are the most effective; this would require a study carried out over one or more years

including following the pollination process through to seed set and fruit yield. Moreoever, as is

well known in pollination research, the vagility and high variability of insect abundance means

that many controlled observation samples of pollinator visitation will result in “zeros”- no visi-

tors. This vastly increases the number of observations needed to carry out statistically analyzable

data. In this rapid assesment, we have focused on characterising a number of crop-pollination

systems, rather than developing datasets for a statistically complete assessment of any one system.

Within the limitations of the present assessment, however, the ecology of pollination in up to twelve

agroecosystems was characterised. In only one of them, deciduous fruit tree farms in South Africa,

were honeybees essentially the only pollinator. In all other farming systems, from Ghana to Kenya,

a wide array of wild insects visited ﬂowers and were seen to be effective pollinators. While honeybee

visits to watermelon are known to be essential to crop production, in Kenya it was shown that two

other bees, nesting in the soil of the ﬁeld, are more effective pollinators. One does not need to be

selected over the other; good management of pollination services in agriculture will promote the

complex of beneﬁcial insects, so that if one is impacted by disease or weather, others may provide a

buffering effect, ensuring that the services are maintained. Information on managing wild ground-

nesting bees in agricultural ﬁelds is virtually non-existant, however.

page 52

ROPS, BROWSE AND POLLINATORS IN AFRICA:

Tree crops often recieve visits from a broadly diverse complex of visitors. In Ghana, the importance

of ﬂies visiting Mangoes was evident, yet proscriptions for maintaining ﬂy populations in mango

orchards are unknown. Papaya’s key pollinator, in observations in Kenya, were long-distance ﬂying

hawkmoths, whose needs and pollination services are spread across mulitple agro and wild eco-

systems. Flies and bees were both important to Avocado pollination in Kenya, although neither

are appreciated adequately or managed. Nut crops such as cashew also have a diverse range of

pollinators, including several larger bees (honeybees, carpenter bees and leafcutter bees) with good

potential as visitors that could be encouraged through pollinator-friendly practices.

Palm crops, such as oil palm and coconut, attract a wide array of small insects, some of which may

not directly pollinate, but serve to disturb male ﬂowers sufﬁciently so that the pollen becomes more

easily wind-borne and is carried to female ﬂowers. This highlights the diverse nature of pollination

services: what is needed is quite speciﬁc to each system, but the role may be carried out by a diverse

group of pollinators.

Groundnuts have traditionally thought to be self-pollinated, but in this assessment as well as in

some other observations in Africa, the ﬂowers attract insects, and the potential for yield increase in

this highly important African crop through pollinator management remains unexplored.

Browse pollinators are important, but often overlooked. Most of the important Acacia pollinators

nest in dead wood, making room for low-tech pollination management in that farmers that depend

on this resource should not denude the areas of dead wood. Browse species such as Indigofera are

shortlived and respond rapidly to changing climatic conditions through establishment by seed, mak-

ing their depedence on pollinators very important.

Coffee producers do not seem to be aware that pollination can increase yields, and are removing

habitat on farm for wild bee populations. The potential for coffee quality to be increased through

management of pollination is gaining considerable public attention, from studies in Costa Rica and

Indonesia. Yet in East Africa, in the center of origin of the domesticated coffee crop, there is no ap-

preciation of the role of pollinators, and habitat on-farm is rapidly being degraded. The reintroduc-

tion of shade-tree coffee to the region, now being discussed amongst regional research networks,

may provide an opporunity to reverse such degradation.

With respect to the taxonomic impediment, it should be noted that many crop and browse pollinator

species could only be identiﬁed to genera. This severely limits our ability to assess whether they are

shared amongst several crops, or speciﬁc to individual crops

This rapid assessment has served to bring to the attention of those involved, that pollinator biodiversity

conservation in agriculture and in natural ecosystems clearly cannot be separated. An ecosystem ap-

proach in pollinator biodiversity conservation must consider a surrounding milieu of well preserved,

natural areas, and patches of wild habitat on-farm, to be an integral part of an agro-ecosystem.

page 53

N INITIAL STOCK-TAKING

Acknowledgements

The contributors to this initial stock-taking wish to acknowledge the support and contribution of

their respective organisations, the Plant Protection Research Institute of South Africa’s Agricultural

Research Council, Environment Liaison Centre International based in Nairobi, Kenya, the Invertebrate

Zoology Department of the National Museums of Kenya ,University of Cape Coast, Ghana, and

the overall support and encouragement of the Food and Agriculture Organization of the United

Nations

Picture Credits

Front Cover; Top, Hawkmoth, Dino Martins; Bottom: Cattle in Forest, Matthew Herren

Page 15: Interview bouquet, Barbara Gemmill-Herren

Page 18: Peach trees in South Africa, Geoff Tribe

Page 24: Male ﬂowers, Watermelon, Hannah Nadel

Page 26: Inﬂoresence and immature fruits of mangoes, Wanja Kinuthia

Page 28: Male ﬂower of Papaya, Female ﬂower of Papaya, and Herse convolvuli, Dino Martins

Page 33: Cashew ﬂowers and young fruit, Peter Kwapong

Page 35: Female Coconut Flowers, Peter Kwapong

Page 37: Groundnut in ﬂower with ﬂower beetle feeding on petals, Peter Kwapong

Page 39: Female inﬂorescence, Oil Palm and Male inﬂorescence, Oil Palm, Peter Kwapong

Page 41: Acacia ﬂowers, Dino Martins

Page 47: Indigofera blossoms and Stingless bee nest entry, Barbara Gemmill-Herren

Page 50: Honeybees on Coffee, Bagged Coffee inﬂorescences, Coffee plantation and riparian forest,

with wild honeybee hives, Barbara Gemmill-Herren

Back Cover: Papaya ﬂower and cowpea ﬂower and bee, Dino Martins, Riparian area in coffee plantation,

Barbara Herren

page 54

ROPS, BROWSE AND POLLINATORS IN AFRICA:

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