Arachnospila wesmaeli (Thomson,1870)
Description and notes
A medium-sized red and black species. Arachnospila wesmaeli belongs to the subgenus Ammosphex, in which the females have a tarsal comb to assist digging the burrow. Females are difficult to identify and require critical examination, the males have a distinct subgenital plate. Identification keys are given in Day (1988).
Distribution
A very local species restricted to coastal sand dunes in England and Wales and inland heaths in the south of England. It is absent from Scotland, Ireland and the Channel Islands.
Occurs in northern and central Europe across to central Asia (Wolf 1972).
Status (in Britain only)
Listed as Rare (RDB3) in Shirt (1987); revised to Notable A (now known as Nationally Scarce (Na) by Falk (1991). Records for this atlas suggest that the latter designation is justified.
Identification
Day, 1988 is the standard work for identifying British Pompilidae. Wiśniowski, B., 2009 is also useful.
Habitat
Arachnospila wesmaeli is a species restricted to very sandy soils with an apparent preference for loose, wind-blown sand.
Flight period
May to September, but most records are for July and August.
Prey collected
There appears to be no data available for Britain. Elsewhere in Europe it has been recorded taking a range of spiders of the families Lycosidae, Gnaphosidae and Salticidae. However, as Richards and Hamm (1939) point out, “records of its habits are of doubtful value, in view of the difficulty of identifying the female.”
Nesting biology
There is little data available.Wasps of this subgenus dig burrows in loose soil having first caught a spider which is left concealed in nearby vegetation.
Flowers visited
No data is available.
Parasites
No data is available.