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).