HOST RANGES OF PARASITOIDS (HYMENOPTERA, BRACONIDAE AND ICHNEUMONIDAE) REARED FROM EPERMENIA-CHAEROPHYLLELLA (GOEZE) (LEPIDOPTERA, EPERMENIIDAE) IN BRITAIN, WITH DESCRIPTION OF A NEW SPECIES OF TRICLISTUS (ICHNEUMONIDAE)

The complex of parasitoids attacking larval stages of Epermenia chaero phyllella in Britain is outlined, and the host range of each of the sp ecies recorded (three braconids and four ichneumonids) is discussed. ' Ecological' factors, such as die behavioural similarity of unrelated h osts during the vulnerable parts of their life histories, seem to have been important in the evolution of the host associations of several o f these parasitoids, even though they are koinobionts. A new species, Triclistus epermeniae Shaw and Aeschlimann, is described.