none A preliminary survey of insects damaging larch cones in 35 stands located throughout Switzerland pointed out the occurrence of six specialized species, mainly Diptera. Five associated parasites and predators have been observed. The attack rate may reach 100% of the cones in some cases but the qualitative and quantitative composition of the insect fauna largely vary among stands in relation to the natural range of european larch. The Anthomyiid flies, Strobilomyia spp., are dominant within the intra-alpine area, where cones are seriously injured. This insect fauna appears directly connected to the one observed in the French Alps. Conversely, the Swiss plateau showed more limited damage due to a reduced fauna that is characterized by the relative importance of Cecidomyiid flies. However, planting practices are assumed to favour the rapid spreading of alpine insects towards lower altitude stands. Nutrition; Diet; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Habitat; Terrestrial habitat; Land and freshwater zones; Palaearctic region; Europe Asynapta aricis (Cecidomyiidae); Switzerland; Pest status on larch & natural enemies Asynapta laricis (Cecidomyiidae); Plant hosts; Population dynamics; Pest status on larch; Forest; Larix decidua (larch), pest status; Switzerland Resseliella skuhravyorum (Cecidomyiidae); Plant hosts; Population dynamics; Pest status on larch; Forest; Larix decidua (larch), pest status; Switzerland; Pest status on larch & natural enemies Strobilomyia (Anthomyiidae); Food plants; Hymenopteran parasites; Records; Population dynamics; Pest status on larch; Predators; Earomyia viridana; Recorded; Forest; Larix decidua (larch), pest status; Switzerland; Pest status on larch & natural enemies Earomyia viridana (Lonchaeidae); Prey; Strobilomyia; Recorded; Switzerland Rhyacionia perangustana (Tortricidae); Food plants; Population dynamics; Forest; Larix decidua (larch), pest status; Switzerland; Pest status on larch Phaenocarpa seitneri (Braconidae ); Ichneumonidae; Figites austriaca (Figitidae ); Dipteran hosts; Strobilomyia; Records; Switzerland; Dipteran host records