Gergely Várkonyi & Matti Ahola: Notes on the larval biology of Xestia borealis (Lepidoptera, Noctuidae). - Entomol. Fennica 12: 78-80.
Observations on a larva of Xestia borealis found in nature are presented. Our findings support the view that the species has a two-year life cycle with two obligatory winter diapauses. Like Xestia sincera, X. borealis seems to prefer buds and fresh shoots of spruce in its diet. Both species overwinter for the first time as large III–IV instar larvae, after overwintering rapidly complete their larval development, and subsequently fall into a long summer diapause. We also discuss some features of larval biology of other boreal Xestia species with a two-year life cycle.