Lemon cuckoo bumblebee
Bombus citrinus is a species of bumblebee known commonly as the lemon cuckoo bumblebee due to its lemon-yellow color. It is native to eastern North America.
This is a cuckoo bumblebee, one that invades the colonies of other bumblebees, kills the resident queen, and takes control over the population of workers inside. Host bees for this species include the common eastern bumblebee (Bombus impatiens) and the half-black bumblebee (B. vagans).
Before the queen invades a nest she forages on various plants, such as asters, thistles, snakeroots, blazing-stars, mountain-mints, and goldenrods.
Like all cuckoo bumble bees, the outer tibial surface of the hind leg is convex and densely hairy, rather than adapted for pollen transport. Their heads are more teardrop shaped and the thorax is predominantly yellow including the lower sides and sometimes down to segment T4 or 5. Hair on the face is usually black with some yellow hairs, there are usually no black hairs on the thorax and would not form a band between the wing bases. Metastomal hairs are short and even and longer on T5 than the other joints and matte with dense punctures on T6. The wings are slightly opaque ranging from a reddish brown to brownish black and yellowish during pubescence. They are sometimes interspersed with black hairs. The male genitalia contain some of the most distinguishing characteristics when differentiating bumble bee species. The gonostylus are lined with long hairs, hairs on the yellow volsella are much shorter. The penis valve is long and thin and relatively straight compared to other bumble bee species.
Found in parts of the Northeastern area of North America. Their distribution includes eastern to central parts of Canada, Northeastern U.S states and parts of the mid-western and southeast regions of the U.S.
