Induction of Diapause in Erioischia Brassicae Bouche (Dipt., Anthomyiidae)

Abstract

1. The overwintering resting stage of the cabbage rootfly (Erioischia brassicae) is a facultative diapause in the pupal instar. 2. The induction of the diapause takes place during larval development and appears to be governed by changes in the daylength operating through the host plant. 3. It is suggested that the daylength stimulus is passed on to the insect by way of a change in the composition of its food, and this hypothesis is supported by the finding that a long-day stimulus remains apparent to feeding insects after the host plant has been removed to short-day treatments.