| | Insects of Britain and Ireland: the bumblebees and cuckoo bees (Bombus and Psithyrus) |
Subgenus. Subgenus Kallobombus.
Biology. Social insects forming organized communities; the larvae feeding on pollen and nectar gathered and prepared by the adult females. Nesting underground.
Adult morphology. Adult queens, workers and males all similar appearance. Adults about 11–17 mm long (queens about 16 mm, workers 12 mm, males 13 mm). The ocello-ocular area of females shining and unpunctured over only about half the distance between the lateral ocellus and the compound eye, conspicuously punctured with intermixed small and large punctures towards the inner margin of the compound eye. Face 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 no posterior tooth. Antennae of the male with the third segment shorter than the fifth; with the third segment shorter than the fourth. Thorax not predominantly ginger-haired; banded (blackish, apart from a lemon-yellow anterior band); black posteriorly, with a pale anterior band only; the light thoracic hairs lemon-yellow. 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. Hind basitarsus of the male with a narrow base and fringed with long hairs on its hind edge. Scutellum of females exclusively black-haired. Scutellum of males black- or predominantly black-haired.
The abdomen medianly black and laterally yellowish adjacent to the thorax, and one or two faint narrow pale bands between it and the white tail, the males additionally with a line of gingery hairs adjoining the white tail. Abdomen conspicuously patterned; with a contrasting tail. The tail white, or buff. Abdomen conspicuously banded between the anterior of the tail and the thorax; with a pale band across the middle, or with one or two faint pale bands between the interrupted anterior black one and the tail (with the first abdominal tergite always black above but yellowish at the sides).
Male genitalia. The sagittae curved inwards around the spatha; smooth to the base, neither serrate nor dentate nor hooked externally; apices apically turned outwards, minutely hooked and apiculate. The ends of the claspers not expanded; dark and horny; conspicuously emarginate and toothed; with the volsella readily visible at their ends.
British representation. Recorded from England, Wales, and Mainland Scotland. Recorded throughout Great Britain but local, declining in the south and lacking from much of south-eastern England and Ireland. The adults abroad during June to October (females), August to October (males). Heathlands and calcareous grasslands.
Illustrations. • Bombus soroeensis, B. terrestris and Apis mellifera: Saunders. APIDAE. 1, Bombus soroeensis, female. 2 and 3, Bombus terrestris, male (2) and female. 4–6, Apis mellifera: male (4), worker (5) and female (6). 7–9, armature of males of B. soroeensis: (7), B. terrestris (8), and Apis mellifera (parts, 9, 9a and 9b). From Saunders (1896). • Male genital capsules of Bombus and Psithyrus. Male genital capsules of Bombus and Psithyrus, routinely displayed as viewed from below. 1–5, PSITHYRUS. 1, P. rupestris; 2, P. vestalis; 3, P. barbutellus; 4, P. campestris; 5, P. sylvestris. 6–17, BOMBUS. 6, B. muscorum; 7, B. humilis ssp. anglicus; 8, B. pascuorum; 9. B. hortorum; 10, B. subterraneus ssp. latreillellus; 11, B. sylvarum; 12, B. ruderarius; 13, B. pomorum; 14, B. lapidarius; 15, B. pratorum; 16, B. SOROEENSIS; 17, B. terrestris. Adapted from Saunders (1896), the nomenclature updated.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the bumblebees and cuckoo bees (Bombus and Psithyrus). Version: 27th July 2019. delta-intkey.com’.
