The Essex Naturalist
35
after a period of decline. Mr S. Wilkinson has recorded it at a number of localities
near Writtle between 1992 and 1997, in his own garden at Chelmsford before
1989 raiding his Victoria plum tree, at Great Leighs in 1993 and Hanningfield
Reservoir in 1996. David Scott has recently sent me a specimen from his garden
at Little Leighs where four were seen flying in an apple tree and reports that
several were seen last year at a nest in a nearby hedge also recording a nest in his
garage roof three years ago. It is possible to confuse Hornet workers with queens
of the social wasp Dolichovespula media which has undergone a remarkable
expansion in its range in the past few years and is now widespread in southern
England as far north as Yorkshire. I would therefore urge recorders, especially
non-specialists, to take voucher specimens so that the scientific validity of their
records can be established. The taking of a voucher specimen will not harm a
colony and despite their size Hornets are relatively docile.
Solitary wasps (Family Sphecidae)
Astata pinguis has been recorded sparingly at further sites in both north and
south Essex during 1996 at Alsa Sand Pit, Alphamstone and West Thurrock
PFA lagoons. Its chrysid parasitoid Hedychridium cupreum has yet to be recorded
in Essex, although it was found at Thamesmead on the Kent side of the East
Thames Corridor this year by Colin Plant and myself where the host was
common on extensive areas of sparsely vegetated shelly sand.
Raymond Uffen has provided a record of the local species Crossocerus cetratus
taken at Hainault Forest on 14th June 1996. This seems to be new for Essex. The
Nationally Scarce (Notable A) Crossocerus distinguendus may be increasing and
has now been recorded from widely scattered sites in the county. New records
come from Barking Levels in South Essex and Alphamstone in North Essex. The
species could occur in many other sites including gardens in the county.
Some local Ectemnius species seem very local in the county. One female
Ectemnius lapidarius was taken at Sawbridgeworth Marsh by Charles Watson on
6th August 1996. The only other records seem to be from the same site and the
nearby Rushey Mead N. R. in 1995 (Harvey & Plant, 1996). Ectemnius lituratus
has heen recorded in recent years at Grays in the East Thames Corridor but new
records for North Essex were made in August 1996 at Alphamstone and Broaks
Wood.
One female of the Nationally Scarce (Notable A) Psenulus schencki was taken at
Barking Levels on 25th July 1996. The specimen was flying around Japanese
Knotweed growing on PFA substrate from the old power station. The foliage of
this same patch of Japanese Knotweed was in favour with a number of other
interesting sphecid aculeates - the plant may have some good points after all!
Females of Pemphredon morio (Notable B) were taken in July 1996 at
Alphamstone in North Essex and in August at West Thurrock PFA lagoons in
South Essex. The Alphamstone specimen would key to P. clypealis using
Richards 1980, but recent work suggests that the species are a single highly
variable species (Falk 1991).