Amegilla bees

Summary

Honey bees are not the only bee species that are significant for human wellbeing. Amegilla bees are a group of native bee species that do not produce honey but are important pollinators of crops and wild plants. Amegilla bees are not aggressive but can sting for defence. They have a mild sting that is much less painful than that of a honey bee. Amegilla bees, often known as banded bees because of their characteristic striped abdomens are medium-sized bees (10-12mm in length) with a golden brown head . Males rest overnight by clinging to plant stems. They live independently of others (i.e. they are solitary) and nest in burrows in the soil, soft sandstone, old mortar or even mud bricks. This fact sheet provides information about these bees to encourage farmers to understand and protect them to help ensure that their crops are effectively pollinated.

From a conservation and agricultural standpoint it is not necessary to recognise all the different bee genera. However, it is important to know that there is a large bee biodiversity. Different bee genera pollinate different plant species, although there is some overlap that acts as a buffer as bee populations wax and wane. For healthy ecosystems, including agro-ecosystems both diversity and abundance in the bee fauna is important.

Scientific Classification

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Hymenoptera

Family: Anthophoridae

Subfamily: Apinae

Tribe: Anthophorini

Genus: Amegilla Friese, 1897

Species in the Genus

About 252 species belonging to the Genus Amegilla have so far been recorded in different parts of the world (ITIS 2010).

Species in Kenya, Tanzania & Uganda

Twenty-seven Amegilla species have been reported inKenya, Tanzania and Uganda (Martins 2004; 2008; Ascher 2010, Eardley and Urban 2010). However, there is need for a thorough survey of the Amegilla bees in the region to give more accurate information on the number of species in these countries and their distributions.

Description

Amegilla bees are not well known by local people (including farmers) in East Africa as the name bee is generally thought only to apply to honey bees. However, many local people who see them at flowers will possibly know that they are bees but think that they are honeybees. Amegilla bees are about 10-12mm in length with a golden brown head, and the abdomen is striped black and pale blue. Bands may differ with the sex, males having more bands (usually 5) than females (usually 4). Males rest overnight by clinging to plant stems. The female of each species can sting but are not aggressive. Stinging may occur particularly if the bee is trapped inside clothing or caught by hand. However, these bees are not aggressive and will not attack.

Possible Causes of Confusion

To the untrained eye these bees can be confused with honey bees as they are similar in size. All species of Amegilla bee can be easily distinguished from the honey bee by observing their behaviour. Amegilla bees do not make honey that people can harvest and do not live in colonies as honey bees do. Furthermore, Amegilla bees carry their pollen between hairs on the hind legs, whereas in honey bees the hind leg has a smooth spoon-shaped area onto which the pollen is glued. Some species of Amegilla bee resemble some Xylocopa species (carpenter bees) but they differ in size with carpenter bees being larger than Amegilla bees.

Distribution in Kenya, Tanzania & Uganda

Amegilla bees are found in most districts/regions of Kenya , Tanzania and Uganda . However, thorough surveys from representative ecosystems are needed to establish what East Africa has in terms of Amegilla bee diversity. Farmers can assist in reporting the presence of these bees in their neighbourhood. This would improve our knowledge of their distribution in the region.

Habitats

Amegilla bees can be found in various habitats (land-uses) inEast Africa from lowlands and coastal lands to the highlands. They are found in forest lands, shrub lands, rangelands, farm lands, marshlands, plains and plateaus. Amegilla bees are common in farmlands, particularly those with some set-aside lands and those close to natural habitats that can provide shelter and nesting sites.

Nesting

Amegilla bees are solitary, nesting in burrows in the soil, soft sandstone, old mortar or even mud bricks. Different species nest in different soil types, which allows them to be present in most ecosystems in East Africa. They are solitary in their behaviour, with only female taking care of the young ones at the earliest stages.

Crops Visited

Amegilla bees often like blue coloured flowers. They are able to perform buzz pollination, which is very important for crops such as tomatoes, eggplants and chillies whose pollen is held firmly by the anthers (Dollin 2001; Bell et al. 2006). This makes them ideal candidates for greenhouse pollination of these crops, which is becoming an important enterprise in East Africa. Species that perform buzz pollination or sonication are able to grab onto the flower and move their wing muscles very fast (making a loud buzzing sound). This shakes the pollen free of the anthers and onto the bee’s body. Many other bees including honey bees rarely perform buzz pollination and will be less able to get the pollen of buzz pollinated plants on to their bodies, and thus cross pollinate. About 8% of the world’s flower plants are mainly pollinated using buzz pollination.

Other Plants Visited

Among the wild plants commonly visited by Amegilla bees are the bottle-brush (family Myrtaceae), grass tree (family Xanthorrhoeaceae) and the saw-edged grass tree (family Xanthorrhoeaceae), all of which are common in East Africa.

Economic / Ecological Importance

Little information exists on the usefulness of these bees to the lives of the people in East Africa. However, they are pollinators and thus they are likely to contribute to increased agricultural productivity and the conservation of the natural biological diversity of the region.

Threats

InEast Africa , Amegilla bees and other bee taxa are threatened by factors such as habitat degradation, agricultural intensification (e.g. replacing hedges with barbed wire fences, and increased use of herbicides which can affect wild flower numbers) and the misuse of insecticides. Amegilla bee populations in East Africa are likely to be affected by pests and diseases but information on this subject is lacking. The lack of knowledge of about these bees and their economic importance by people (de facto custodians of nature) is significant as their conservation and management practices implemented at the farm level will depend to a large extent upon the value that people attach to them.

Conservation and Management Practices

There are now concerted research efforts in the region to develop best practices for conservation and management of bees that are compatible with other good farm practices, to enhance crop production. Theoretically, bee conservation and management is inexpensive and adopted activities can also improve the aesthetic value of the landscape. Such practices involve setting land aside (e.g. a 1-metre strip) in the farmland to host all year round food resources for the bees, as well as safer sites for nesting, mating, resting and refuge from natural enemies. During flowering, farmers should manage pesticide usage carefully to avoid poisoning flower-visiting bees. Farmers should also minimise pesticide drift from the field to adjacent areas. Laws governing registration and use of plant protection products indirectly play a major role in the protection of pollinators. Trampling by people and livestock and tilling should be managed to conserve the nesting sites of soil-nesting species such as Amegilla bees. KARI (the Kenya Agricultural Research Institute) is developing protocols for mass rearing of different species of solitary bees. Any successful results from this research will be freely communicated to the public. In addition, KARI is collaborating with other stakeholders to ensure in situ conservation and management of bees for pollination purposes. Much of the work of conserving native bees will be underpinned by raising public awareness of the importance of these species.

Legislation (National and International)

There is not yet any legislation in East Africa that explicitly addresses pollinators. However, there is scattered legislation for the protection of biodiversity particularly that covering environmental protection, protection of wildlife and heritage sites, protection of forests and natural resources such as water catchments. In addition, laws governing registration and use of plant protection products also indirectly play a major role in the protection of pollinators Such legislation, together with market-based mechanisms such as the Good Agricultural Practices (GAPs) codes and practices may help to protect bees albeit incidentally. At the international level, the Conservation on Biological Diversity (CBD) is spearheading strategies to enforce bee management for pollination purposes within the member countries, which include Kenya, Tanzania and Uganda. Farmers should lobby their governments to develop Integrated Pest Management policies that would protect bees and other insects of importance in agriculture.

References

1. Ascher JS (2010) Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila). http://www.discoverlife.org/mp/20q?guide=Apoidea_species&flags=HAS: accessed 26 Dec 2010.

2. Bell MC, RN Spooner-Hart and AM Haigh (2006) Pollination of Greenhouse Tomatoes by the Australian Bluebanded Bee Amegilla (Zonamegilla) holmesi (Hymenoptera: Apidae). J Econ Entomol 99(2): 437-442.

3. Dollin A (2001) Blue Banded Bees: Potential Pollinators of Glasshouse Tomatoes. Australian Native Bee Research Centre. http://www.aussiebee.com.au/aussiebeeonline002.pdf, accessed on 31Dec 2010.

4. Eardley, C.D. (1994) The Genus Amegilla Friese in southern Africa (Hymenoptera: Anthophoridae). Entomology Memoir, Department of Agriculture, Republic of South Africa, No. 91, 68 pp.

5. Eardley CD. and Urban R 2010 Catalogue of Afrotropical Bees (Hymenoptera: Apoidea: Apiformes). Zootaxa 2455:1-548.

6. ITIS (2010) Amegilla  Friese, 1897: Taxonomic Serial No.: 634005. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=634005. Accessed December 2010.

7. Martins DJ (2004) Foraging patterns of managed honeybees and wild bee species in an arid African environment: ecology, biodiversity and competition. Intern J Trop Insect Sci 24(1): 105–115.

8. Martins DJ (2008) Pollination observations of the African Violet in the Taita Hills, Kenya . J EA Nat Hist 97 (1): 33-42.

9. Michener CD (1974) The social behaviour of the bees. Belknap Press, Cambridge, USA

10. Michener CD (2007) The Bees of the world, the John Hopkins University Press, Baltimore and London , pp 913.

Editors

Théodore Munyuli, Busitema University - Uganda; Muo Kasina, Kenya Agricultural Research Institute (KARI) - Kenya; Juma Lossini, Tropical Pesticides Research Institute (TPRI) – Tanzania; John Mauremootoo, BioNET-INTERNATIONAL Secretariat – UK; Connal Eardley, Plant Protection Research Institute (PPRI) – South Africa.

Acknowledgements

We recognise the support from the Kenya Agricultural Research Institute (KARI), Tropical Pesticide Research Institute (TPRI)Tanzania and Busitema University (Faculty of Natural Resources and Environmental Sciences) - Eastern Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).

Contact

BioNET-EAFRINET regional coordinator: eafrinet@africaonline.co.ke