This funny little creature, Braula coeca (Pronounced Browler Seeker), is commonly – but mistakenly – known as the ‘bee louse’. In fact it is a type of fly, although one which can’t, being wingless.
The BBKA’s Module 3 syllabus says ‘The Candidate shall be able to give: …an outline account of the life cycle of Braula coeca, its effect on the colony and a description of the differences between adult Braula and Varroa”.
Below is an infographic on Braula coeca which I had a go at making using Prezi. Even though it’s not particularly complex, this took me ages! Respect to infographics creators.
If you have trouble reading the infographic, click on this Printer-friendly pdf version to see a larger version.
Braula is similar in size and colouring to a varroa mite. However, an adult Braula coeca has much more prominent legs than varroa (six legs compared to varroa’s eight) and more of a classic beetle shape with its head at its narrowest point, whereas a varroa mite is crab shaped, its legs protuding out slightly at its widest point.
Since beekeepers started treating against varroa with miticides, Braula coeca numbers have plummeted, but they used to be regularly observed riding the back of adult bees like little jockeys. While on the head of its host bee, B.coeca will lean forward and feed on food from the mouthparts of its host, as the bee is feeding or exchanging food with another bee.
They are particularly fond of queens, with several congregating on a queen’s back when they are present in a hive. More than 180 adults have been found on a single queen (Source: University of Florida entomology department). This is likely to be because queens are fed regularly and consume greater quantities of food than worker bees.
As they only steal a small amount of their food, rather than feeding on their haemolymph or developing larvae, Braula are not particularly harmful to honey bees. However, large numbers of them riding on a queens’ back must be a nuisance, and the developing larvae tunnelling through the wax cappings of honey cells (as described in the infographic) is a pain for beekeepers wanting to produce cut comb. Extracted honey with the cappings removed will be fine, but biting into cut comb will reveal the tiny larvae of the Braula within the cappings.
Reference: University of Florida entomology department ‘Bee louse’ page (very helpful and great microscopic photos)
The Module 3 exam is on Saturday, and I’m really not feeling confident about it. Between starting a new job and trying to find a wedding venue, I haven’t had as much time to revise as usual. I’d love to pass, but if I don’t I’ll go back to revising and retake in November.