Crossocerus aphidum LEPELETIER & BRULLÉ 1835
One of the smallest of a genus of small, predominately black, wasps. It seems to be genuinely scarce throughout its world range, but is very widespread. The female is very similar to that of Crossocerus wesmaeli, which can be abundant on light sands, but the male has a very distinctive peg on the underneath of the 7th antennal segment. For more comment on the separation of females see Edwards (1982).
Known from South-eastern England only:West Kent, Surrey and West Sussex. This species has not shown any great increase in range over the past twenty years, unlike many other species which are presumed to be highly thermophilic. However, a record made at Ambersham Common, a very well recorded site, in 2005 represents the first record for W. Sussex north of the Downs. Overseas, sporadic and rarely found, but distributed across central and southern Europe and Asia to Manchuria.