Afranthidium bees

Summary

Honey bees are not the only bee species that are significant for human wellbeing. Afranthidium bees are a group of native bee species that do not produce honey but are likely to be important pollinators of crops and wild plants. Females have a sting, but they are not aggressive and will only sting if handled. Afranthidium nest in natural cavities and live independently of others (i.e. they are solitary). They are between 7mm and 13mm in length and have long tongues. 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: Megachilidae

Subfamily: Megachilinae

Tribe:  Anthidiini

Genus: Anthidiini Michener, 1948

Species in the Genus

The genus Afranthidium is a group of solitary bees with about 60 known species from southern Europe andAfrica.

Species in Kenya, Tanzania & Uganda

Eardley and Urban (2010) list two species of Afranthidium bees fromTanzania but it is very likely that these species also occur in Kenya and Uganda (Munyuli, in press). A comprehensive list of Afranthidium species for the region has not yet been produced.

Description

Afranthidium bees are not well known by local people (including farmers) inEast Africa. These insects are not usually recognised as bees by local people in East Africa , where the name bee is generally thought only to apply to honey bees. Afranthidium bees have long tongues and can feed on both deep and shallow flowers. Most Afranthidium bees in East Africa are pollen-collecting bees. In East Africa , they are known to visit flowers of crops but they appear to mainly visit wild flowering plants. Their importance as effective pollinators in agriculture has yet to be established. However, they may be effective pollinators of wild plant species; hence the need to protect them.

Possible Causes of Confusion

Some insect species can be mistaken for Afranthidium bees. These include other bee species in the tribe Anthidiini (which include Afranthidium and Pachyanthidium bees ). They can be distinguished by microscopic characteristics that are described in the key that accompany these fact sheets. Afranthidium bees can also be confused with some flies and wasps. Flies are different in that they have large eyes and two wings while bees have smaller eyes and four wings. In addition, most flies that may be confused with these bees do not collect pollen from flowers. Wasps have a constriction (“waist?) at the junction of their abdomen and thorax which is absent in bees.

Distribution in Kenya, Tanzania & Uganda

Afranthidium bees have been recorded in Tanzania and thus are likely to be present in Kenya and Uganda as well but their distribution needs to be determined. 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

Afranthidium bees are likely to be present in various habitats (land-uses) in East Africa such as grasslands, natural forests, marshlands, protected areas, farmlands, rangelands, woodlands, woodlots (forest plantations), along river edges (riparian areas) and in coastal areas.

Nesting

Afranthidium bees live independently of others (i.e. they are solitary). They build their nests in sheltered locations in pre-existing natural cavities such as burrows, crevices and hollow twigs that can be found in less disturbed and dry habitats.

Crops Visited

Afranthidium bees visit a variety of flowering crop species belonging to different plant families inEast Africa. In Uganda they have been seen visiting a few crops such as cowpeas and simsim (sesame).

Other Plants Visited

Afranthidium can forage on a range of wild plant species (trees, shrubs, herbs, weeds, lianas) found in different habitats. These bees preferentially visit plant species with small purple and blue, milk cream flowers.

Economic / Ecological Importance

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

Threats

InEast Africa, Afranthidium 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. Farming practices that involve over-digging of soils in any type of habitat threaten populations of these bees since they often nest in underground burrows. Trampling by people and livestock can affect nesting sites. Afranthidium 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 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 also 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 those species that nest in burrows. 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.

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. Eardley CD, Gikungu MW and Schwarz MP (2009) Bee conservation in Sub-Saharan Africa andMadagascar: diversity, status and threats. Apidologie, 40: 355–366.

2. Eardley CD, Kuhlmann M and Pauly A. (2010) The Bee Genera and Subgenera of sub-Saharan Africa. ABC Taxa vol 7: i-vi, 138 pp. http://www.abctaxa.be/volumes/vol-7-bees

3. Eardley CD and Urban R (2010) Catalogue of Afrotropical bees (Hymenoptera: Apoidea: Apiformes). Zootaxa, 2455: 1–548.

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

5. Munyuli T (in press) Pollinator biodiversity in  Uganda  and in Sub-Sahara Africa: Landscape and habitat management strategies for its conservation. International Journal of biodiversity and conservation.