none Milk Parsley, Peucedanum palustre (L.) Moench, is best known to British entomologists as the foodplant of Papilio machaon L. However, it is also the host for more delicate insects such as leaf-miners. On 12. vii. 1983 the author collected several mines from plants beside a dyke at Upton Fen, E. Norfolk (NGR 63/3813). In the following week several larvae left the mines to form puparia. On 29-31. vii. 1983, two male and one female Phytomyza thysselini Hendel emerged, as well as two braconids. Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Land and freshwater zones; Palaearctic region; Europe; United Kingdom Phytomyza thysselini (Agromyzidae); Hymenopteran parasites; Exotela cyclogaster & Opius; Plant hosts; Peucedanum & Selinum; Records; Europe; Distribution range; England; Norfolk; First record for England, plant hosts & hymenopteran parasite records Exotela cyclogaster; Opius (Braconidae ); Dipteran hosts; Phytomyza thysselini; Records; England; Norfolk; Records from dipteran host