Bombus bohemicus (Gipsy Cuckoo Bee)  

After emerging from hibernation a queen will find a nest of Bombus lucorum with a few workers. The female enters the nest, kills the host queen and takes over the egg-laying for the colony. These eggs produce only new B. bohemicus females and males, which take no part in the running of the colony, all work being done by the host workers.

Unlike other bumblebees in cuckoo species the back legs that are covered in hair, with no pollen baskets and the wings that appear dusky or dark. in B. bohemicus the females tend to have one pale yellow band on their thorax but none on the abdomen. Males may have sparse patches of yellow hair on the first segment of the abdomen. The tails are mostly white, but have yellow patches on the right and left sides. This species is very variable and it is often not possible to confirm identification in the field.