| | Insects of Britain and Ireland: the bumblebees and cuckoo bees (Bombus and Psithyrus) |
B. agrorum (Fabricius); subspecies floralis (Gmelin in Linnaeus), septentrionalis Vogt, and vulgo Harris
Brown-banded carder bee.
Subgenus. Subgenus Thoracobombus.
Biology. Social insects forming organized communities; the larvae feeding on pollen and nectar gathered and prepared by the adult females. Nesting on the surface of the ground, or only just below.
Adult morphology. Adult queens, workers and males all similar appearance. Adults about 10–18 mm long (queens about 16–18, workers 10–15, males 13–14). The hair coats of abdomen and thorax fairly conspicuously colour-patterned to more or less homogeneously coloured or merely shaded darker to lighter (males being variable regarding patches or bands of black hairs); predominently sandy- to gingery-brown. Face somewhat longer than wide. The facial hairs of males gingery brown; vertex gingery-brown haired. The facial hairs of females gingery brown to yellow and black. The clypeus of females with scattered large to medium punctures over most of its surface, including much of the central area. The mandibles of the females round-ended, not oblique. The mid antennal segments of the male each noticeably swollen only apically underneath. Thorax dark predominantly ginger-haired (but with a few black hairs intermingled); not banded. 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 extended to form a sharp angle of less than 45 degrees, or produced into a narrow tooth or spine.
The abdomen ginger, but the hairs somewat paler than those of the thorax and with variable intermingling or patches of black hairs. Abdomen fairly conspicuously patterned (with black zones in some males), or not conspicuously patterned; predominently ginger haired; without a contrasting tail. The abdomen of females exhibiting some black hairs laterally, at least on the sides of tergites 2–4. Abdomen with black hairs intermixed among the ginger ones. Abdominal pubescence relatively long, uneven and somewhat ragged. Sternite 2 of females with a weak rounded transverse ridge between the anterior and posterior margins.
Male genitalia. The sagittae curved inwards around the spatha; smooth to the base, neither serrate nor dentate nor hooked externally; apices apically minutely punctate, not hooked. The ends of the claspers much expanded; dark and horny; conspicuously emarginate and toothed; with the volsella hidden by the squama.
British representation. Recorded from England, Wales, Mainland Scotland, Orkney, Channel Isles, and Ireland. Widespread throughout the British Isles. The adults abroad during March to October (females), June to October (males). In divers habitats, common in gardens.
General comments. The commonest of the British ginger bumblebees.
Illustrations. • B. pascuorum: queen and male (photo). • British Bombus species (4): Saunders. APIDAE. 1 and 2, Bombus liepeterseni (= muscorum ssp. liepeterseni) male (1) and female. 3, B. anglicus (= humilis ssp. anglicus), female. 4–6, B. pascuorum: male (4), female (5), and a variety of the female (6). 7–9, male armature of B. liepeterseni (7), B. anglicus (humilis ssp. anglicus) (8), and B. pascuorum (9). From Saunders (1896). • cf. Bombus pascuorum (Carder Bee): as Bombus cognatus, Stephens 1846. • Comparing females of B. pascuorum and B. lapidarius with associated Cuckoo-bees (P. campestris and P. rupestris). Comparing female Cuckoo-bees with females of the host Bumblebees. At left, Psithyrus campestris (above) and Bombus pascuorum (below); at right, Psithyrus rupestris (above) and Bombus lapidarius (below). 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’.
