Summary

Honey bees are not the only bee species that are significant for human wellbeing. Macrogalea 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. These hairy, medium sized, long-tongued bees are only found in sub-SaharaAfrica. Macrogalea bees nest in soft, dead plant stems and live independently (i.e. they are solitary). 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.

Common Name (Language)

Small carpenter bee (English). Bees of the tribe Allodapini share this common name with bees in the genus Ceratina

Scientific Classification

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Hymenoptera

Family: Apidae

Subfamily: Xylocopinae

Tribe: Allodapini

Genus: Macrogalea Cockerell, 1930

Species in the Genus

Current knowledge about Macrogalea shows that bees in this genus are restricted to sub-Saharan Africa. There are ten known species (Eardley and Urban 2010).

Species in Kenya, Tanzania & Uganda

Four species of Macrogalea have been reported fromKenya, Tanzania and Uganda (Eardley, Kuhlmann and Pauly 2010) including one species, Macrogalea mombasae, known to be social parasite (i.e. it occupies the nests of other species – in this case it occupies the nests of other Macrogalea species).

Description

Macrogalea 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. Macrogalea bees are medium-sized, mostly less than 1 cm in length with most areas of the body covered in hairs.

Possible Causes of Confusion

Macrogalea bees could be confused with Braunsapis bees . It is possible to distinguish these bees since Macrogalea bees are hairier and slightly larger.

Distribution in Kenya, Tanzania & Uganda

There is little information about their distribution in different parts of Kenya, Uganda and Tanzania . However, it is likely that they are found in most districts/regions of these countries. 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

Macrogalea bees can live in different ecological zones so long as these can support their nesting and food requirements.

Nesting

Macrogalea bees are solitary bees that construct their nests in soft, dead plant stems in which they bore tunnels.

Crops Visited

The authors could find no reported information on crops visited.

Other Plants Visited

Macrogalea bees are common on acacia trees.

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. They are common on acacia trees and presumably pollinate these trees. Acacia pods are food for livestock during dry periods.

Threats

InEast Africa, Macrogalea 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. Macrogalea 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 hiding 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. 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