Diapause Initiation and Alterations in the Life Cycle of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) as Induced by Photoperiodic Conditions

摘要

Grapholita molesta (Busck) is one of the major pests of Rosaceae, causing significant damage to buds and fruits. In Southern Brazil, its population density is reduced during Rosaceae dormancy months. The present study evaluated the influence of different photoperiods (L:D) (10:14, 11:13,12:12,13:11,14:10 and 16:8) at 25 ± 1°C and 60 ± 10% RH on diapause induction of G. molesta eggs, larvae, prepupae, and pupae. The effects of the photoperiod on the life cycle of non-diapausing insects and on the second generation were also assessed. Prepupal diapause was observed only when eggs and neonates (< 12h-old larvae) were exposed to photophases from lOh to 14h long. Development of non-diapausing individuals and those from the second generation tended tobe longer in photophases between lOh and 14h long.