24
The Essex Naturalist
recent records but most of the remaining areas of interest are under threat from
development and it is to be hoped that sufficient mosaic of habitat can be saved
to maintain the national importance of this undervalued area.
Ruby-tailed wasps (Family Chrysididae)
The Nationally Rare (RDB3) Hedychridium coriaceum was found in numbers
flying around patches of bare ground in grassland at Curtismill Green on 28th
June 1995. It is a parasitoid of the common sphecid wasp Lindenius albilabris
which was nesting in the areas of bare ground. Colin Plant took one individual
at Dolphin Pit, Thurrock on the 5th July 1995. The Nationally Rare (RDB3)
Hedychrum niemelai, a parasitoid of the RDB3 sphecid Cerceris quinquefasciata,
was found in numbers with its host at East Tilbury silt lagoons and also at the
Dolphin Pit in July and August. One individual of the local Spinolia neglectus was
found at Mill Wood Pit, Thurrock on 4th May 1995. I know of no other records
for the county.
Family Tiphiidae
One male of the Nationally Scarce (Notable B) wasp Tiphia minuta was taken at
Ferry Fields, Thurrock on the 25th June 1995. The larvae are probable
parasitoids of dung beetle larvae. A number of species of dung beetle have been
found at the site including the Nationally Rare (RDB3) Aphodius consputus.
Recording at Ferry Fields in 1994 and 1995 has shown the site to have an
important invertebrate fauna including two species represented on the "top one
hundred priority species" for target action plans for Great Britain drawn up by
The Biodiversity Challenge Group. These are the large and impressive Robber
fly Asilus crabroniformis and the bumblebee Bombus sylvarum. The site is
currently zoned as primary land for industrial development although a
Railfreight planning application was recently rejected by Thurrock Council. It
remains to be seen if the outcome of the public inquiry into the Draft Local Plan
will affect the status of the site, identified by Essex Wildlife Trust as a SINC
(Site of Importance for Nature Conservation).
Velvet ants (Family Mutillidae)
One female of the Nationally Scarce (Notable B) Large Velvet Ant Mutilla
europaea, a parasitoid of bumblebees, was taken at Ferry Fields on 29th June
1995 and a male was found at East Tilbury on 1st August.
Family Sapygidae
One male and two females of the Nationally Scarce (Notable B) Club-horned
Sapyga Sapyga clavicornis were taken at Fobbing Hill, South Essex on the 16th
and 21st June 1995 flying around Stellaria flowers.
Spider wasps (Family Pompilidae)
One female of the Nationally Scarce (Notable A) Aporus unicolor, a parasitoid
of the Purse web spider Atypus affinis was collected at Mill Wood Pit, Thurrock
on the 19th July 1995 by Colin Plant. This appears to be the only recent record