A scarce and little known species in Britain, only recently added to the British list (Guichard 2002). It is very similar to the common P. gracilis and great care must be taken with determination as the characters are subtle. Ecological differences between the two species have been reported by Westrich & Schmidt (1983), who found that P. gracilis was foraging for aphids on herbaceous plants, whilst P. turionum was foraging for aphids associated with trees.
South-east England, including Surrey, Berkshire, North Hants, West Sussex, East Sussex, West Kent and East Kent.
Probably a boreo-alpine species in Europe; it is common in Finland, for example (Lomholdt 1975-76). The species is adventive in North America, being found from Pennsylvania and New Jersey to Texas along the coast, and inland in Michigan, Indiana and Ohio. It was first collected in the 1940's but not identified until 1961 (Krombein 1961).
Not listed in Shirt (1987) or by Falk (1991) but its status clearly needs to be assessed.
The few known British localities are mainly sandy heaths or mixed woodlands. The species is sparsely distributed in coniferous plantations in Denmark (Lomholdt 1975-76).
Late May to early September.
Arboreal aphids are reported as prey by Westrich & Schmidt (1983).
Falk has reared this wasp from beetle burrows in old Scots pine bark from Ambersham Common in West Sussex, and M Edwards collected one entering old beetle burrows in Scots pine bark in Rewell Wood, West Sussex (pers. comm.). Abroad, nests have been found in the galls of the moth Petrova resinella (Lepidoptera, Tortricidae) on Pinus species, including P. contorta and P. sylvestris (Lomholdt 1975-76). This moth also occurs in Britian and its galls may harbour P. turionum. Nest closures and an adult female are illustrated by Blösch (2000).
No information available.
The chrysidid wasps, Omalus biaccinctus (not British) and O. aeneus have been found as parasites/parasitoids in Europe (Lomholdt 1975-76).
2002
Proofed: June 2012