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The Essex Naturalist
Interesting Hymenoptera records for 1997-1998
P.R. Harvey
32 Lodge Lane, Grays, Essex RM16 2YP.
Hymenoptera records of particular interest for 1997 and 1998 together with
several other additional records are briefly described below and update the
provisional list published in Harvey & Plant (1996) and my Recorder Report for
1996/7 in last year's Essex Naturalist. There are several new county records and
other species are recorded for the first time since Harwood (1902). Unattributed
records have been made by the author.
Habitats in the East Thames Corridor and around the Colchester area
continue to demonstrate the remarkable biodiversity of rare and scarce species
to be found in parts of Essex. The best habitats for aculeate Hymenoptera
include various 'brown field' sites such as old sand pits, brick pits, silt lagoons
and PFA (pulverised fuel ash) lagoons, especially where these are associated
with adjacent areas of unimproved or remnant old habitats. Work this year has
reinforced the recognition of Barking PFA lagoons as an exceptional
invertebrate site. Survey at old sand pits in the Stanway area of Colchester and
the Rainham Marshes silt lagoons also indicates their importance.
Unfortunately all these brown field sites are under development threat. At
Barking PFA lagoons the Invertebrate Index and Species Quality Index
(measures of the national rarity and diversity of the fauna) for the species of
aculeate Hymenoptera, Diptera and Arachnida recorded from the PFA lagoon
area totals at least 2380 and 12.9 respectively, very high figures which compare
favourably with some of the best sites in the East Thames Corridor. This
includes 6 Red data Book (RDB) species, 17 Nationally Scarce and 52 Nationally
Local species. Apart from the very high biodiversity of other rare species present
there is the RDB category 1 (Endangered) Tachinid fly Gymnosoma nitens which
is parasitic on the Nationally Scarce bug Sciocoris cursitans, and a very large
population of the Silvery leaf-cutter bee Megachile leachella, nesting in the
weathered desert-like areas of PFA and foraging on Birds foot trefoil Lotus
corniculatus.
Part of the Barking PFA area has been a London Wildlife Trust reserve, but
apparently the whole site will soon be cleared and developed for a massive
housing complex, planning permissions having been in place since the 1980s.
The Barking Levels to the east of the power station have already largely been
developed for housing and soon little natural or semi-natural habitat will
remain.
Ruby-tailed wasps (Family Chrysididae)
Charles Watson took the Nationally Scarce (Na) ruby-tailed wasp Omalus
puncticollis on the 28th July 1997 at Chrishill and this appears to be new to