Distribution and Prolonged Diapause of the Rowan Seed Predators Argyresthia conjugella (Lepidoptera: Yponomeutidae) and Megastigmus brevicaudis (Hymenoptera: Torymidae) and their Parasitoids in Norway

The seed predator Argyresthia conjugella Zeller has rowan as its preferred host plant; in years of poor fruiting rowan, it oviposits on apples. To improve the knowledge this apple pest, rowanberries were collected from localities all over Norway 1971 to 1985, and predators their parasitoids allowed emerge for up five years. Two species predators, A. Megastimus brevicaudis Ratzeburg, seven parasitic Hymenoptera common. distribution these is shown EIS (European Invertebrate Survey) maps Norway. biology summarized based published literature behavior during emergence. tendency delayed emergence, which an indication prolonged diapause, was more pronounced M. than conjugella, former appearing Five also three them a high degree, Prolonged diapause must be taken into account studies rowanberry insect guilds.