Photoperiodic induction of adult reproductive diapause in the ladybird beetle Cycloneda munda (Coleoptera: Coccinellidae)

The developmental response and the induction and duration of adult hibernal diapause in a North American population of Cycloneda munda (Say) (collected at 38 degrees N, 84.5 degrees W) was determined by rearing individuals at four photoperiods (L : D 16 : 8, 14 : 10, 12 : 12, and 10 : 14) at 22 degrees C. Preimaginal development of C. munda individuals was slower at L : D 10 : 14 than at three longer photoperiods. No C. munda females reared at L : D 16 : 8 entered diapause, 5% of females at L : D 14 : 10 were in diapause, whereas shorter photoperiods (L : D 12 : 12 and 10 : 14) induced diapause in 84% and 100% of females. Cycloneda munda females demonstrated a long-day response to photoperiod, similar to that observed in several other species of predaceous Coccinellidae that diapause as adults.