13
Psithyrus rupestris (Fabricius)
This species is both nationally and in Essex our rarest species. There are a few recent records
from the Thames estuary, and from the north east of the county. It is a parasite of Bombus
lapidarius, which it resembles closely in colouration.
Psithyrus barbutellus (Kirby)
This species is parasitic on Bombus hortorum, and, like its host, is widespread and relatively
common in the county. The 'tail' of the male is white, with black hairs at the tip.
Psithyrus campestris (Panzer)
This species is parasitic on Bombus pascuorum, but is by no means as widespread. It appears to
be rather local in Essex, with populations concentrated in the south west, north east, and along
the Thames estuary. The females usually have a distinctive yellowish 'tail', whilst the males
have two more-or-less equally common colour forms. In one, the groimd colour is black, with
some white hairs on the hind segments of the abdomen. In the other, there are two yellow bands
on the thorax, and the 'tail' is yellow.
Psithyrus sylvestris (Lepeletier)
This species is parasitic on Bombus pratorum, and is similarly common and widely distributed
in the county. The males have white tails (although as in campestris there are melanic forms),
but can be distinguished from the males of barbutellus by the presence of ginger hairs at the
extreme tip of the white 'tail'.
Acknowledgements
I am very much indebted to the following, for specimens, records, advice and oilier help:
M. P. Attwood. K. M. Black. I. P. Bowdrey, S. Burden, D. Corke, D. E. Deacon, G. Else,
M. Edwards, M. A. Fremlin, M. J. Gregory, M. W. Hanson, J. J. Heath, Neil Harvey,
P. R. Harvey, K. Hill, P. Kent, R. D. Kent, G. J. Lucas, S. Massey, G. Moore. E. Parsons,
R. G. Payne, S. L. Pennington. H. F. Perry. C. W. Plant, J. Rose, K. M. Rowland. R. D. Ruffell,
D. A. Smith, G. Smith, G. Wilkinson.
References
ALFORD, I). V., 1975. Bumblebees. London: Davis-Poynter
BKNTON, T., 1995. 'Bumblebees (Hymenoptera: Apidae) in north east Essex'. Nature in North East Essex
1993, 35-44. Colchester: CNHS
EDWARDS. M.. 1997. Bumblebee Working Group Report for 1997. West Sussex: M. Edwards.
EDWARDS. M.. 1998. U.K. B.A.P. Bumblebee Working Group Report, 1998. West Sussex: M. Edwards.
FALK, S., 1991. A Review of the Scarce and Threatened Bees, Wasps and Ants of Great Britain.
Peterborough: N. C. C.
HARVEY. P.R., 1997. Interesting Hymenoptera Records for 1996 and 1997. Essex Naturalist (New Series)
14:
HARVEY, P.R., 1998. Aculeate Hymenoptera in Essex: Provisional Distribution Maps. P.R. Harvey.
Essex
INSTITUTE OF TERRESTRIAL ECOLOGY, 1980. Atlas of the Bumblebees of the British Isles.
Cambridge: ITE
PRYS-JONES, O. E. and Corbet. S. A. 1987 Bumblebees. Cambridge: Cambridge University.
Essex Naturalist (New Series) 16 (1999)