A survey to inventory the natural enemies of the horse-chestnut leafmining moth, Cameraria ohridella Deschka and Dimic (Lepidoptera, Gracillariidae) and to evaluate their relative abundance, was conducted from 2001 through 2003 in Lombardy, northern Italy. Two predators and 10 parasitoids were found during the 3-year survey. An increasing number of parasitoid species associated with the leafminer was detected (4 species in 2001, 5 in the 2002 and 10 in 2003). Eulophidae (Hymenoptera: Chalcidoidea) were most represented: Mina tetrastichus frontalis Nees, Closterocerus trifasciatus Westwood, Pnigalio pectinicornis L., Pnigalio agraules Walker, Pediobius saulius Walker, Chrysocharis pentheus Walker, Cirrospilus talitzkii Boucek, Sympiesis sericeicornis Nees, Baryscapus nigroviolaceus (Nees). Only one Ichneurnonidae (Hymenoptera: Ichneumonoidea) was found during 2003: Itoplectis alternans (Grav.). Haplothrips (Thysanoptera) : Predator Cameraria ohridella (Gracillariidae) : Host, Prey Itoplectis alternans (Ichneumonidae) : Parasite Eulophidae (Chalcidoidea) : Parasite Campyloneura virgula (Miridae) : Predator Nutrition; Diet; Prey; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Predators; Land zones; Palaearctic region; Eurasia; Europe Cameraria ohridella; Food plants; Aesculus hippocastanum; Hymenopteran parasites; Natural enemies survey; biocontrol limplications; long-term study; Eulophidae & Itoplectis alternans; Insect predators; Tubuliphera (Thysanoptera) & Miridae (Hemiptera); Italy; Lombardy Campyloneura virgula; Haplothrips; Insect prey; Predator survey; biocontrol implications; long-term study; Cameraria ohridella (Lepidoptera); Italy; Lombardy Eulophidae; Itoplectis alternans; Lepidopteran hosts; Parasitoid survey; biocontrol implications; long-term study; Cameraria ohridella; Italy; Lombardy none