The rains that have brought out the flowers around TBI have also brought out a large number of insects. Like many of the plants, the insects are active and taking opportunity of the greenery to forage and breed. And like the plants they are all under intense pressure to complete their life-cycles. For insects this often involves several stages as eggs, larvae, pupae and finally adults.
Deserts and drylands are often mistakenly thought to be places of low diversity. However, they are rich in insect life, but most of this is hidden away awaiting the brief periods of flowering. As this time is now upon us, it has been very exciting for the students to glimpse some of the incredible bee diversity in this habitat. One of the groups of insects that are more diverse in drylands, especially in Africa, are the bees. These are wild bee species. Many people are surprised to learn that there are more than just honeybees. Bee diversity in this area is largely unexplored and no doubt many exciting new species and biology remains to be discovered.
We started out watching and collecting bees on the Indigofera spinosa bushes within the TBI compound. A number of bees have been frantically visiting the tiny pink flowers. The students have collected several different bee species on the Indigofera. These include some large leafcutter bees who carry pollen on their bellies, which turns them bright yellow. Another common bee visiting the flower was a Pseudapis. Also visiting the flowers was a striking parasitic cuckoo bee species (Coelioxys) that is a brood parasite of the leafcutter bees. Just like the cuckoo bird, it lays its eggs in the nests made by the hardworking leafcutter bees!
We then travelled to a site in the open desert plains where a carpet of miniature flowers pressed close to the ground was busy with bee activity.
Here we found several different bees that we hadn’t seen nearer TBI. These included a beautiful halictid or sweat bee with a bright orange abdomen.
We also spent time catching parasitic wasps and bees that were tiny. These are so tiny that we had to use small bags and slip them quickly over the bees as they were foraging, as they could wriggle through the holes in the nets! The students worked hard and learnt a lot about bee diversity and how much work it is to study them!
The students also collected data on visitation rates to flowers on the Indigofera bushes. This species is really important as it is the main browse for goats and camels which are the livestock species that people depend on in the drylands of Turkana. We found that solitary wild bee species are both the most abundant and the most efficient pollinators as they carry pollen between many different individual plants resulting in effective cross-pollination. The Indigofera bushes establish new plants from the seeds that only come about as a result of pollination by the wild bee species. So the bees feed the goats and camels indirectly!
More from the world of bees and bugs at TBI soon…