By Dino J. Martins
One of the most wonderful things about being an entomologist in East Africa is that there is so much that is new and undiscovered.
We have made lots of discoveries, including some new species, and revealed that this part of the world is particularly rich in different kinds of bees.
Some of the most amazing bees we have been lucky to find are those in the melittidae family, commonly known as melittids.
A couple of years ago, following some brief, precious rains, I found myself out in the bush in Turkana wandering around overwhelmed. One morning I settled down by a flowering clump of the ubiquitous spiny legume that dominates in the South Turkwel region, Indigofera spinosa.
The hot, bright sun beat down, made all the more intense by the crisp, clear skies following the days of rain. The flowers before me a plethora of bees zipped in and out — making the most of this rare feast of pollen and nectar.
Several familiar bees buzzed in and out — the rotund Pseudapis overloaded with pollen on their hind legs, several different leafcutter bees, carrying pollen on their bellies and the striking black and white Coelioxys bees that are parasites of the leafcutters.
Then flying low over the sand an orange spark of colour wove its way towards the flowers.
Immediately I realised this was something special and unusual. Scrambling for my net, I took a wild swoop for it. I missed. The bee escaped and no doubt laughed at my clumsy efforts.
Disappointed, but not discouraged, we returned to the same location the next day and found that the strange bee came back to the flowers at about the same time. We only found a couple of them and despite searching for many months, none came back.
In September last year, following some rains, the bees reappeared. This time I was able to track them carefully and watch some of their behaviour as they visited the flowers.
We followed the bees carefully and studied their behaviour. This allowed us to work out what one of the most remarkable features of this genus is used for in females.
The long, curved dagger-like spurs on their hind legs appear to be involved in assisting with foraging on the flowers of legumes.
The bee grips the flower and presses down separating the wing petals. The pressure on the keel of the flower exposes the flowers’ anthers, which then are rapidly and furiously combed through the curved spur and the inner surface of the hind legs to strip them of pollen.
Being bright orange, they are easy to spot as they zip about the low-growing flowers that appear after the rains. Things dry up quickly in the Turkana heat and they only have a couple of days to gather enough pollen for their larvae.
The female of this bee nest in the ground, digging tunnels in the sand, where they make small cells that hold the stores of pollen and their young ones. Each female collects food for her own larvae and cares for her own nest individually. There is no sharing and cooperation like in the more familiar honeybees.
They lay eggs on the stored pollen, which then hatch into larvae, grow and eventually develop into pupae.
Although we still do not fully know what happens underground, it is most likely these pupae that survive the long droughts in a state of suspended animation, known as aestivation, then emerge as adult bees when the rains finally come. In the future we hope to be able to study the nests of these bees.
Once we had a few specimens, the bee then went on a worldwide journey to be described by scientists.
Working with Professor Laurence Packer of York University, one of the world’s leading experts on bee taxonomy and biology, a description was prepared and I was able to add information on the behaviour and ecology to this from field observations in Turkana.
We also sequenced the DNA of the bees — just one gene from the mitochondria, called cytochrome oxidase I (COI). This gene can be used as a marker to gauge differences between species.
We used this to work out the relationship between the new bee, Samba turkana, and its relatives — further establishing that it was indeed a new species.
One of the mysteries that still remain to be uncovered is where the males are and what exactly they look like. We haven’t found any yet. This in itself is not unusual, as in many insects males can be very rare, with highly female biased sex ratios.
The description was published in the scientific journal ZooTaxa in February 2015 and we named the new bee ‘Samba turkana’, choosing to honour the region, its cultures and biodiversity.