| | Insects of Britain and Ireland: the bumblebees and cuckoo bees (Bombus and Psithyrus) |
Humble- or Bumble-bees.
Biology. Social insects forming organized communities; the adult populations including specialised, sterile females constituting ‘workers’; the larvae feeding on pollen and nectar gathered and prepared by the adult females. Nesting underground, or on the surface of the ground, or only just below (also in locations provided by humans, such as coat pockets, lawn mowers, furniture drawers, etc.).
Adult morphology. Adults about 10–22 mm long. The mandibles of the females round-ended, not oblique. Antennal segments 12 (females), or 13 (males). Thorax banded, or not banded (unpatterned black or ginger, or conspicuously patterned with black and grey, whitish, pale brownish, yellowish or gingerish). Closed fore-wing cells 6–10. 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.
The abdomen when concolorous, black, dark brown, reddish brown, ginger or rarely yellow; when patterned, black-and-orange or reddish orange, black-and-brown or reddish brown, black-and-yellow, black-and-white, black and grey and yellow, or black and yellow and white. Dorsally visible abdominal segments 6 (females), or 7 (males). Abdomen not conspicuously patterned, or conspicuously patterned. Sternite 6 of females without ventro-lateral keels.
Male genitalia. The ends of the claspers dark and horny.
British representation. About 20 species in the British Isles (with over twenty subspecies); recorded from England, Wales, Mainland Scotland, Hebrides, Orkney, Shetland, Channel Isles, and Ireland. Throughout the British Isles.
General comments. The adult males have no sting and bigger eyes than the females, as well as 13-segmented antennae that are longer than the 12-segmented ones of females. In addition to details of the hind tibiae (q.v.), Bombus adults differ from those of Psithyrus in the often less pigmented wings; the female abdomen is hairier, less pointed and softer, exuding wax between its segments, and the mandibles are more toothed (for moulding wax) than pointed..
Illustrations. • Bombus lapidarius (Red-tailed Bumble-bee: Shaw and Nodder, about 1800). • British Bombus spp. (1): Saunders. APIDAE: 1–6, British Bombus species. 1, Bombus sylvarum (female). 2 and 3, B. rudarius (male and female, respectively). 4, B. pomorum (female). 5 & 6, B, lapidarius (male and female, respectively. 7–10, armature of males: 7, B, sylvarum; 8, B. rudarius; 9, B. pomorum; 10, B. lapidarius. From Saunders (1896). • British Bombus spp. (2): Saunders. APIDAE. 1 and 2, Bombus jonellus, male (1) and female. 3 and 4, B. monticola, male (3) and female. 5, B. pratorum, female. 6, B. cullumanus, female. 7, armature of male B. pratorum. From Saunders (1896). • British Bombus species (3): Saunders. APIDAE. 1–2, Bombus hortorum, male (1), female (2). 3, female Bombus ruderatus subspecies perniger (as B. hortorum var. harrisellus). 4 and 5, B. subterraneus ssp. latreillellus, male (4) and female. 6, B. distinguendus, female. 7 and 8, armature of the males of B. hortorum (7) and B. subterraneus ssp. latreillellus. From Saunders (1896). • 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). • 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). • cf. Bombus pascuorum (Carder Bee): as Bombus cognatus, Stephens 1846. • Bombus ericetorum Panzer (Heath Humble-bee), cf. male B. subterraneus: B. Ent. 564. • Bombus ericetorum: B. Ent. 564, legend+text. • Bombus ericetorum: B. Ent. 564, text cont.. • 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’.
