DIAPAUSE IN CHRYSOPA CARNEA (NEUROPTERA: CHRYSOPIDAE): I. EFFECT OF PHOTOPERIOD ON REPRODUCTIVELY ACTIVE ADULTS

Abstract

Upon transfer to a photoperiod of LD 12:12 all young, reproductively active Chrysopa carnea Stephens, reared and maintained under LD 16:8, showed a rapid decline in fecundity. One group entered diapause, as shown by the cessation of oviposition within 22 to 34 days, fat body accumulation, and an associated colour change. The females in this group resumed oviposition within 3 to 7 days after being returned to LD 16:8. Females in the other group under short-day conditions continued to oviposit, but at a lower rate than those kept under constant LD 16:8. Our data indicate that the imago is sensitive to both long-day and short-day photoperiods and that some males and females enter a facultative reproductive diapause which is induced and terminated in this stage solely by manipulating the adult lighting regimen.