Physiological Entomology (2012) 37, 185–191 DOI: 10.1111/j.1365-3032.2011.00810.x Inheritance of photoperiodic induction of larval diapause in the Asian corn borer Ostrinia furnacalis QIN-WEN XIA 1 , CHAO CHEN 1 , XIAO-YUN TU 2 ,HUI-ZHONG YANG 1 and F A N G - S E N X U E 1 1 Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Jiangxi Province; Key Laboratory of Physiology, Ecology and Cultivation of Double Cropping Rice, Ministry of Agriculture; Institute of Entomology, Jiangxi Agricultural University Nanchang, Nanchang, China and 2 College of Life Sciences, Jiangxi Normal University, Nanchang, China Abstract. The Asian corn borer Ostrinia furnacalis (Guen´ ee) enters facultative diapause as fully-developed larvae in response to short-day conditions. As a consequence of geographical variation in photoperiodic response, moths from Nanchang (28 ◦ 46 ′ N, 115 ◦ 50 ′ E) enter diapause in response to short day-lengths (D strain), even at the high temperatures whereas moths from Ledong (18 ◦ 47 ′ N, 108 ◦ 89 ′ E) exhibit almost no diapause under the same conditions (N strain). In the present study, crosses between the two strains are used to evaluate the inheritance of diapause under different photoperiods at temperatures of 22, 25 and 28 ◦ C. The moths, both reciprocal crosses and backcrosses, show a clear long-day response, similar to that of the D strain, suggesting that the photoperiodic response controlling diapause in this moth is heritable. However, the critical day-length for induction of diapause is shorter in hybrids than in the D strain. The N strain also shows a short-day photoperiodic response at the lower temperature of 22 ◦ C, indicating that the N strain still has the capacity to enter a photoperiodically-induced diapause, depending on the rearing temperature. The incidence of diapause in all crosses is highest with D strain fathers or grandfathers and lowest with N strain fathers or grandfathers, indicating that the male parent has significantly more influence on the incidence of diapause of subsequent progeny than the female. The results obtained from all crosses under LD 12 : 12 h or LD 13 : 11 h photocycles at 25 ◦ C show that inheritance of diapause in O. furnacalis does not fit an additive hypothesis and that the capacity for diapause is transmitted genetically in the manner of incomplete dominance. Key words. Diapause, inheritance, Ostrinia furnacalis, photoperiodic response. Introduction Diapause is a genetically-determined and environmentally- controlled developmental arrest that allows insects to survive harsh seasonal conditions. The expression of diapause is subject to both genetic and environmental factors (Beck, 1980; Tauber et al., 1986). It is known that most insects enter diapause in response to photoperiod, and many insects show clinal geographical variation of the critical photoperiod for diapause induction within the same species: the higher Correspondence: Fang-Sen Xue, Institute of Entomology, Jiangxi Agricultural University Nanchang, Nanchang 330045, China. Tel.: +86 79 1382 8081; e-mail: xue_fangsen@hotmail.com the latitude, the longer the critical photoperiod (Danilevskii, 1965; Bradshaw, 1976; Beck, 1980; Tauber et al., 1986; Danks, 1987; Saunders, 2002). Cross-mating of strains from different geographical areas reveals that there are various modes of inheritance of diapause in different species. Crosses made between geographical strains for the knot-grass moth Acronycta rumicis, the arctiid moth Spilosoma menthastri, the cabbage butterfly Pieris brassicae and the satin moth Leucoma salicis show diapause tendency characteristics for all F 1 hybrids that are intermediate between those of their parents (Danilevskii, 1965), indicating that the genetic control of the photoperiodic response is polygenic for these species. Crosses between the Kuopio population of the fruit fly Drosophila littoralis from Finland (62 ◦ 55 ′ N) and the Ticino population  2011 The Authors Physiological Entomology  2011 The Royal Entomological Society 185