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A report on the status of the Shrill carder bee Bombus sylvarum in Essex
P.R. HARVEY
32 Lodge Lane, Grays, Essex RM16 2YP
Abstract
Bombus sylvarum is a priority National of the species in Essex is reviewed and
Biodiversity Action Plan species that the results of fieldwork and
has undergone a dramatic national observations on its ecology during 1998
decline this century. The current status are discussed.
Introduction
The dramatic national decline of the Shrill carder bee this century has been to so great that in
1997, despite very great efforts and many hours in the field by members of the Bumblebee BAP
Group, it was recorded from only two localities in south-east England and one in South Wales,
and the species may be in danger of becoming extinct in the British Isles (Philp 1998).
There are old records from north-east Essex but in 1993 and 1994 the author discovered the
species at Wat Tyler Country Park and Ferry Fields (Tilbury) in south Essex. This was followed
by a sighting of two workers at Broom Hill (West Tilbury) in 1996 by Prof. Ted Benton.
Unfortunately despite the presence at the Ferry Fields site of populations of two priority
Nalional Biodiversity Action Plan species, the Shrill carder bee and the Hornet robber fly and an
important fauna comparable to that of SSSIs in the east Thames region. English Nature would
not commit themselves to making an objection to a Port of Tilbury planning application to
develop the site. Outline planning permission was granted in December 1996 without an impact
assessment on the effect of development on the status of these two species in Essex or any
requirement for mitigation. The future of both BAP species at the site is doomed and it is not at
all clear that the other south Essex populations will be able to survive in the long term. Large
scale loss and fragmentation of habitats seems to be the major cause of decline of much of our
national flora and fauna and there is increasing evidence that long-tongued bumblebees require
areas of 10-20 sq. km. containing a complex of suitable habitat to sustain viable populations (M.
Edwards pers. comm.). Grazing regimes and their levels and timing are critical for both the
Shrill carder bee and the Hornet robber fly and the availability of a network of suitable habitats
within a relatively large area is almost certainly essential if either species is to survive local
extinctions.
The 1998 fieldwork
The author visited fourteen sites in Essex to search for Bombus sylvarum including potential
sites in North Essex where there are old records for the species (ITE 1980). Bombus sylvarum
was only found at two sites both in south Essex, Wat Tyler C.P. where it was recorded in 1993
and a new site at Benfleet Downs. Most of the other sites visited were either too heavily grazed,
grazed throughout the summer, cut for hay or as management (e.g. the sea walls) or simply not
flower-rich enough.
At Wat Tyler two workers and one male were seen on the 9thAugust 1998 and then over 20
workers were seen on the 12th August by the author and attendees to a meeting held to
Essex Naturalist (New Series) 16 (1999)