Bombus campestris
Bombus campestris is a very common cuckoo bumblebee found in most of Europe.
Description
The bumblebee is of medium length, the queen having an average length of, and the male. The fur of the queen is quite thin on the dorsal side. The collar, and in some cases the top of the head, is orange-yellow, while the terga 3–5 have yellow sides with a black centre; the rest of the body is black. The fur of the male is more variable: A pale form exists, with a broad, pale yellow collar, yellow hairs on top of the head, pale hairs on the sides of the otherwise black first tergite, a yellow line along the posterior rim, terga 3–6 pale yellow, usually with a black, thin, centre line. As for the queen, the rest of the body is black. The dark form is entirely black except for a thin, diffuse band on the collar and yellow hairs on the sides of terga 4–6. Intermediate forms exist. Both queens and males can be melanistic. In western Scotland, the subspecies B. c. swynnertoni is found, with a queen with an almost entirely pale yellow thorax, yellow hairs on terga 1 and 2, and a yellow tail. The male has more black on the thorax, but a lot of yellow on the abdomen.Ecology
Its main hosts are bumblebees of the subgenus Thoracobombus such as Bombus pascuorum. In continental Europe, it also parasitizes nests of brown-banded carder bees and early bumblebees.Both sexes visit green alkanet, devil's-bit scabious, and thistle flowers. The queen also flies to dandelion, red clover, germander speedwell, and ground ivy, while the male feeds on bramble and knapweed.