The Essex Naturalist
59
Evagetes crassicornis (Shuckard)
Unlike most Pompilidae, those in the genus Evagetes are cleptoparasitic on other
pompilid wasps, the female eating the host pompilid egg and substituting her
own which then feeds on the prey provided by the original pompilid host. E.
crassicornis is probably parasitic on Arachnospila anceps and Anoplius nigerrimus
and other species.
Our three recent records, from Mucking Heath, Mill Wood Pit and West Mersea
are indicative of a species likely to be found in other areas with diligent searching.
Aporus unicolor Spinola - Notable A
Listed for South Essex by Falk (1991) without details.
This pompilid is restricted to preying on the trap-door spider Atypus affinis - the
only British mygalomorph species. The spider attacks insects by biting them
through its silken tube then cutting a hole to draw them in; the wasp must
somehow evade being killed in this way whilst still gaining access to the tube to
sting the spider.
Our only record is from Mill Wood Pit at Grays, where a female was taken on
19th July 1995.
SUBFAMILY CEROPALINAE
Ceropales maculata (Fabr.)
Female Ceropales wasps seek out other pompilids in the act of carrying away
their spider prey, drive them away and using the modified ovipositor insert an
egg into a lung-book of the spider. She then flies away, leaving the spider where
it is whereupon the original captor normally returns and carries the spider to its
burrow. The Ceropales egg hatches first and the larva immediately seeks out the
egg of the original pompilid, eats it, and then continues to devour the paralysed
spider. Several pompilid "host" species are listed.
Angelica flowers, St Osyth (Harwood 1884). We have no other records than this.
Unknown species
Pompilus chalybeatus Schiodte
This species was not rare one sunny morning last autumn, on a small sandy
hillock among clay cliffs at Walton-on-Naze, but was exceedingly active and
difficult to capture (Harwood 1884). We are uncertain to which species the
author is referring.
SCOLIOIDEA
Although included in the Aculeata, the Scolioids are entirely parasitic in habit
and have close affinities with the Parasitica, especially the Bethyloidea. British
species parasitise various bees and wasps and number only eight, none of them
particularly widespread or common, distributed in three families (two in
Sapygidae, 4 in Tiphiidae, and 2 in Mutillidae). All are recorded for Essex.
Ecological notes are taken from Richards (1980).