Passaloecus clypealis Faester,1947
Synonyms
Passaloecus angustus GUSSAKOVSKIJ 1952
Description and notes
Passaloecus species are small to very small, elongate, black wasps which nest particularly in beetle borings in posts and other cavities, and prey on aphids. The biology of this species is described by Merisuo (1973), and keys to the European species groups of the genus Passaloecus are in Merisuo (1974).
Distribution
Entirely restricted to south-eastern England, with most modern records from east Norfolk, the Thames corridor and Dungeness.
Abroad, this species is widely distributed throughout central and northern Europe, but found only rarely. Also occurs in western Russia, eastwards to Uzbekistan (Lomholdt 1975-76).
Status (in Britain only)
Listed in Shirt (1987) as Vulnerable (RDB2), and in Falk (1991) as Rare (pRDB3).
Habitat
Found around reed beds in brackish and fresh water.
Flight period
June to August.
Prey collected
The prey is unknown but may be aphids, in common with other species of its genus.
Nesting biology
The species has been reared by G H L Dicker from Lipara lucens (Diptera, Chloropidae) galls in common reed and also from the cut, hollow stems of the reed itself (Dicker 1978). Abroad, honeysuckle stems are also used as nesting sites (Lomholdt 1975-76). Nest construction has not been observed, but as in all other Passaloecus, the cell partitions and nest closure are probably made from a mixture of resin and small pebbles.
Flowers visited
Not known to visit flowers; adults of the wasp are seldom encountered in the field.
Parasites
Abroad, Trichrysis cyanea is recorded as a parasitoid (Lomholdt 1975-76).
Year profile last updated
2002