Reproductive diapause in Speyeria (Lepidoptera: Nymphalidae)

Abstract

A delay in ovarian development (reproductive diapause) occurs in adult females of S. coronis (Behr) and S. zerene (Boisduval) from California [USA] during the warm-dry weather of the summer flight period. Females copulate soon afte emergence; males show little evidence for a delay in spermatogenesis. Termination of the female diapause is hastened by injection of juvenile hormone and by exposure to short-day photoperiods. Diapause delays the onset of oviposition until later summer or early fall and thus decreases the exposure time of overwintering 1st instar larvae to desiccating conditions.