The Influence of Photoperiod and Temperature on the Induction of Diapause in Diataraxia Oleracea L. (Lepidoptera)

Abstract

The induction of diapause in the pupa of Diataraxia oleracea is influenced by temperature and photoperiod during the larval stage. Low temperatures and short photoperiods tend to induce diapause while high temperatures and long photoperiods tend to prevent diapause. Diapause is not influenced by light intensity during the larval stage providing the intensity is above a certain minimum. Diapause is prevented at high temperatures (30-34° C.) if the larvae are reared in darkness. The photoperiod is operative as a factor influencing diapause only between the beginning of the moulting sleep prior to ecdysis to the last instar and the 3rd-5th day of the last instar. A single diapause-preventing photo-period during the moulting sleep is probably sufficient to prevent diapause. Diapause in D. oleracea is not influenced by photoperiodically controlled substances in the larval food plant.