previously been found in Kent, West Sussex, Surrey and Hampshire,
three specimens being taken in consecutive years on a dead tree near
Winchester (George Else, personal communication). The species is a
parasitoid of the larvae of other aculeates, possibly of the Sphecid
genus Trypoxylon, which is quite frequent at the Chadwell site. It is,
like these wasps, a long thin species.
The rare (RDB3) Hedychrum niemelai Linsenmaier is a parasitoid of the
larvae of the rare (RDB3) solitary wasp Cerceris quinquefasciata and
possibly other Cerceris species. Both John Felton and myself recorded
the Chrysid and its host at the Chadwell site in 1992 and both species
have also turned up in 1993 at an old sand pit at Linford (TQ6680) and
at Mill Wood Pit (TQ5978) near "Lakeside" in Thurrock.
I took one female of the nationally notable (Notable A) Chrysis schencki
Linsenmaier (det. J. Felton) at Grays Chalk Quarry (TQ6079) in late
August 1993. The species is apparently scarce with poorly known
requirements. It was described as new to science in 1968 and may
prove to be under-recorded. Post-1970 information is known for seven
widely scattered localities. It is thought to be a parasitoid of the larvae
of other aculeates but the host(s) is far from clear (Falk, 1991).
Solitary Wasps
Family Sapygidae
I took a single male of the Club-horned Sapyga Sapyga clavicornis (L.)
(Notable B) at Chadwell in 1993. The wasp is a cleptoparasite of
megachilid bees of the genera Chelostoma and Osmia, Chelostoma
florisomne featuring commonly in British records. It is associated with
dead wood in situations fully exposed to the sun (Falk, 1991). The
Sapyga was taken inside an old sand pit at the top of the site which has
a number of old fence posts exposed to the sun. A large rotten log that
was also present has since been vandalised and kicked to pieces.
Osmia caerulescens, 0. ventralis and 0. rufa all occur in this same area
but Chelostoma has not been recorded at the site.
Family Mutillidae
The Large Velvet ant Mutilla europaea Linnaeus (Notable B) is a
parasitoid of bumble bees Bombus, with occasional reports of attacks
on honey bees. There are widely scattered records throughout England
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