Some interesting aculeate Hymenoptera records for 1999-2000
Mike Edwards also recorded the species along the old rifle butts at Wennington Marshes on 12
August 2000. Nomada rufipes and its probable host in Essex, Andrena denticulata, are both very
rare in the county, and must be considered vulnerable. The Nomada was fairly frequent at Mill
Wood Pit site, but otherwise the only other modern county records are for Broom Hill at West
Tilbury, a single female collected by Jerry Bowdrey at Colchester Cemetery (TM0023) on 10 July
1996 and another female collected by the author at Barking (TQ4682) on 27 July 2000.
Epeolus cruciger is also very rare in the county, although often common on heathlands. It is a
cleptoparasite of Colletes succinctus, almost always a heathland species associated with heather
flowers, and Colletes marginatus, a rare coastal dune species. Epeolus has previously been recorded
in Essex from Barking Reach (TQ4782), where L. Clemons collected it with Colletes succinctus on
12 August 1990 and East Tilbury silt lagoons (TQ6977), where the author collected one female on
7 July 1995 and Mike Edwards recorded it again on 20 August 2000. The colony of the host Colletes
succinctus at Barking Reach, where the author also collected males and females on 21 and 27 August
1996, is unlikely to survive the extensive housing developments. This is unfortunate since the bees
are clearly not using heather as a pollen source, and it would be extremely interesting to establish
exactly which plant species are being used. At East Tilbury the host is evidently Colletes marginatus,
and the same appears to be true at Northwick, Canvey (TQ7386), where one female E. cruciger was
collected by the author between 17 August and 1 September 2000.
The Nationally Rare (RDB3) Blue Carpenter-bee Ceratina cyanea had what must have been one of its
largest British populations at the Mill Wood Pit site, now a housing development. It has otherwise
occurred in numbers in the county only at St Clements Church tract (TQ5977), where much of the
habitat will be destroyed by a car park and staff canteen development by Procter & Gamble, and at
Wennington riverside where the habitat is likely to be lost to landfill and restoration work. Fortunately
the bee seems to be present at very low population levels in the vicinity of these sites, with one male and
two females collected by the author at Aveley Bay (TQ5379J on 13 June and 6 July 2000, a record by
Mike Edwards on 12 August 2000 along flie old rifle butts at Wennington Marshes (TQ5479), one
female collected by the author near Arena Essex (TQ5879) between 27 August and 27 September 1999
and one male collected by Adrian Knowles at the Tilbury EWT Centre (TQ6576) on 25 August 2000.
The bee was noted as fairly common in the Colchester area by Nicholson (1928) and survives today,
with records by Adrian Knowles of one male and female at Middlewick Ranges (TM0022) on 25 August
1999 and one male at Old Heath Cliff Paddock (TM0123) on 7 August 2000.
The much declined national Biodiversity Action Plan bumblebee species Bombus humilis and B.
sylvarum both have nationally important populations in Essex. B. humilis is currently numerous at
various sites in south Essex along the East Thames Corridor from as far west as the Isle of Dogs just
in Middlesex to as far east as Benfleet and Leigh. However it is found in open flower-rich grasslands,
especially those found on 'brownfield' sites, and many of its sites arc being developed or will be lost
within a few years. The dramatic declines of the Shrill Carder-bee B. sylvarum mean that it now
survives in Britain only in south Essex and north Kent, Salisbury Plain, the Somerset Levels (where
it may be on the point of extinction) and two parts of south Wales. Work during 2000 confirmed that
Northwick, Canvey contains one of the most numerous populations remaining in the UK. However
government determination to redevelop 'brownfield' sites at any cost and the development pressures
on the East Thames Corridor from the Thames Gateway mean that the long-term prospects for both
bumblebees arc not good. It is ironic that post-industrial sites are viewed as 'brownfield' when large
areas of the modem countryside, with their fertilized and 'improved' species-poor grasslands and
pesticide-drenched arable fields, are in fact far more a wildlife desert and 'brownfield' than any
wasteland.
Essex Naturalist (New Series) 18 (2001)
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