Effect of photoperiod on developmental fitness in Ophraella communa (Coleoptera: Chrysomelidae)

Abstract

Ophraella communa LeSage (Coleoptera: Chrysomelidae) is an important biological control agent of the common ragweed, Ambrosia artemisiifolia L., in China. Development and fecundity of O. communa, and hatch rate of progeny eggs were studied at five photoperiods (8:16, 10:14, 12:12, 14:10, and 16:8 [L:D] h). The highest survival rate of eggs was 92% at the photoperiod of 16:8 (L:D) h, and those of both larvae and pupae were observed at the photoperiod of 14:10 (L:D) h (85 and 96%). The shortest developmental durations of larvae and pupae were observed at photoperiods of 14:10 and 16:8 (L:D) h. Fecundity was 1,159-1,976 eggs per female from photoperiods of 8:16 to 16:8 (L:D) h. The hatch rates of progeny eggs were 67-92% from photoperiods of 8:16 to 16:8 (L:D) h, and photoperiods did not affect developmental duration of progeny eggs. The intrinsic rate for increase (r), the net reproductive rate (r0), and the finite rate of increase (λ) reached the maximum values at 16:8 (L:D) h (0.2219 d(-1), 721 hatched eggs and 1.2484 d(-1), respectively) and 14:10 (L:D) h (0.2133 d(-1), 605.6 hatched eggs and 1.2378 d(-1), respectively). Their minimum values were observed at the photoperiod of 8:16 (L:D) h, which were 0.1731 d(-1), 212.2 hatched eggs and 0.1890 d(-1), respectively. The shortest T value was 29.7 d at a photoperiod of 16:8 (L:D) h and the longest was 31.4 d at a photoperiod of 12:12 (L:D) h. Our study shows that O. communa could survive and reproduce successfully at different photoperiods, thus may expand its distribution to regions with different photoperiods.