Observations on the parasitoid complexes of budmoths (Lepidoptera: Tortricoidea) on larch in Europe

Abstract

AbstractThis paper reports the results of a survey of parasitism of budmoths on larch in Europe as part of a programme to determine the potential of European parasitoids for the classical biological control of the North American defoliator, Zeiraphera canadensis Mutuura & Freeman. The parasitoid complexes of Zeiraphera diniana (Guenée), Exapate duratella (Heyden), Ptycholomoides aeriferanus (Herrich-Schäffer) and Spilonota laricana (Heinemann) are determined from field-collected samples of host larvae and pupae. The parasitoid complexes are characterized by their component guilds and the mean apparent parasitism of the individual species. Host phenology appears to affect the parasitoid complex of the larch budmoths. Parasitoids that attack the young larval instars are better represented from hosts that overwinter as larvae, while parasitism is dominated by the guilds that attack the late larval instars in hosts that overwinter as eggs. The study identifies the ichneumonids, Phytodietus spp., Chorinaeus cristator (Gravenhorst) and Phaeogenes osculator (Thunberg) for further experimental investigation as potential candidates for the biological control of Z. canadensis.