British Insects: Bumblebees and Cuckoo-bees
Subspecies audax (Harris), syn. virginalis (Geoffroy in Fourcroy).
Subgenus. Subgenus Bombus s. str.
Biology. Social insects forming organized communities; the larvae feeding on pollen and nectar gathered and prepared by the adult females. Nesting underground.
Adult morphology. Queens unlike workers and males in appearance (with the thoracic and abdominal yellow banding is somewhat broader in the males than workers). Adults about 11–22 mm long (queens about 20–22, workers 11–17, males 14–16). Face relatively short; at least as wide as long, or wider. The facial hairs of males black; vertex black haired. The facial hairs of females black; vertex black haired. The mandibles of the females round-ended, not oblique; females with a fairly conspicuous posterior tooth. Antennae of the male with the third segment at least as long as the fifth; with the third segment considerably longer than the fourth. Thorax not predominantly ginger-haired; banded (blackish-greyish with a broad yellow anterior band in males and a narrower one in females); black posteriorly, with a pale anterior band only; the light thoracic hairs lemon-yellow, or mid-yellow, or mustard yellow, or gingerish yellow, or orange-yellow (broader, lighter and brighter in males). The outer surface of the hind tibiae of females with a conspicuous pollen basket, in the form of an elongate, shiny, hairless, area framed by stout hairs. The hind tibiae of the males having a fringe of long hairs along the outer margin. Mid basitarsus of females with the distal-posterior margin broadly rounded to narrow, but if pointed forming an angle of more than 45 degrees, not projected into a tooth or spine. Scutellum of females exclusively black-haired. Scutellum of males black- or predominantly black-haired.
The abdomen of queens black with an orange band across the middle and an off-white tail, in the less contrastingly patterned workers and males blackish-greyish with the central yellow band paler and the tail white. Abdomen conspicuously patterned; with a contrasting tail. The tail white to greyish white, or buff, or orange-red (occasionally). Abdomen conspicuously banded between the anterior of the tail and the thorax; with a pale band across the middle.
Male genitalia. The sagittae rather straight to curved inwards around the spatha; smooth to the base, neither serrate nor dentate nor hooked externally; apices slightly divergent, and laterally bidentate. The ends of the claspers not expanded; dark and horny; conspicuously emarginate and toothed; with the volsella hidden by the squama.
British representation. Recorded from England, Wales, Mainland Scotland, Channel Isles, and Ireland. Common and widespread throughout most the British Isles except the far north and Scotland. The adults abroad during February to September (females), or May to September (males).
General comments. Workers of B. lucorum and B. terrestris are probably not reliably distinguishable in the field.
Illustrations. • B. terrestris: queen and worker (photo). • Bombus soroeensis, B. terrestris and Apis mellifera: Saunders. • Male genital capsules of Bombus and Psithyrus.
To view illustrations with legends giving names in current use, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa, as well as source references and other relevant material.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: Bumblebees and Cuckoobees. Version: 1st January 2012. http://delta-intkey.com’.