| Abstrakt: |
Abstract: Seasonal variations in adult body size in Harmonia axyridis (Palls，1773) were analysed over four consecutive generations according to sex and state of melanism. In males there was a difference in body size in the four generations. The difference was significant in melanics and marginally significant in nonmelanics. However，in females，a significant difference in body size was observed only in melanics. Males in summer 1987 were significantly larger than those in 1988 in both melanics and non-melanics. Males in spring were significantly larger than those in summer only in melanics in 1988 and males in summer were significantly larger than those in spring only in non-melanics in 1987. On the contrary, in females in 1987，melanics in spring were significantly smaller than those in summer. Furthermore. no significant difference was observed in non-melanic females in the four generations. The sex ratio in melanics was significantly female biased in spring 1988. While, the sex ratio in non-melanics was significantly female-biased in spring 1987 and summer 1988. The mean temperature during the hibenation period before spring 1988 was lower than that before spring 1987 and for the average for the same period for 1966 to 1995, and the difference between the minimum and maximum temperatures before spring 1988 was larger than that in 1987 and the long term average for this period (1966 to 1995). These results suggested that sex- and morph-related difference in cold tolerance during hibernation may affected the variations in body size and the sex ratio of the spring generation of H. αxyridis. |
