The Essex Naturalist
69
T. figulus L.
Said to nest in a variety of cavities, including woodworm Anobium holes, cut
stems, hollow roots, etc. provisioning the nest with spiders. It probably has a
greater tendency towards using banks and walls as nest sites, unlike T.
medium.
Listed for the Colchester area by Harwood (1884) without further detail.
However, at that time, the following species, T. medium was regarded as a mere
form of figulus and so it is not entirely clear to which species Harwood was
referring. Our only recent records, certainly of this species, are from East Ham
N.R. in 1984 (P Kirby), Fingringhoe Wick in 1986 (M Edwards) and from Mill
Wood Pit, Grays, where both sexes were recorded in 1995.
T. medium Beaumont
Nests in a variety of cavities, including woodworm Anobium holes, cut stems,
hollow roots, etc. provisioning the nest with spiders.
Recorded from Broom Hill (West Tilbury), Mill Wood Pit, Grays and Heybridge
Gravel Pit. This wide spread of records suggests under-recording.
SUBFAMILY CRABRONINAE
Crabro cribrarius (L.)
The enlarged front legs of the male - a feature of the genus - are diagnostic.
This large sphecid preys on flies including Asilidae, Therevidae, Empididae,
Syrphidae and various Muscoidea.
Listed for the Colchester area hy Harwood (1884) without further detail.
Recorded at Fingtinghoe Wick in 1963 (Stebbing 1965). Mucking Heath at
Orsett, the Rodbridge Valley Walk in the extreme north of the county and
Broom Hill at Chadwell are the three known sites for this species at present.
Crossocerus (Crossocerus) distinguendus (Morawitz) -Notable A
Nests in the ground on sandy/gravely slopes fully exposed to the sun. Only
recently (1981) added to the British list and currently known from less than 50
sites.
Listed for South Essex by Falk (1991) who refers to a 1989 record made by M W
Hanson; this is in fact the first county record which Hanson made at Yardley
Hill, Epping Forest (Hanson 1992). The widely spread recent records from the
Dunmow Railway Line, Dolphin Quarry, Curtismill Green, Grays town and
Foulness Point seem to suggest that Essex is well blessed with this uncommon
species.
C. (Crossocerus) elongatulus (Van der Linden)
Nests in the ground or in old tunnels in timber. Preys on assorted small flies.
Widely spread at a number of sites in the Purfleet-Grays-Tilbury area of South
Essex. Away from this area it is only recorded from Hainault in 1989 (M
Hanson) though it is very probably under-recorded.