The effect of feeding and mating on the development of flight muscle in Agrotis ypsilon
Author of the article:WANG WeiYIN JiaoCAO YaZhongLI KeBin
Author's Workplace：State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing100193, China
Key Words：Agrotis ypsilon, unfeeding, mating, ultrastructure of flight muscle, degeneration of flight muscle
Abstract：The development of flight muscles in adult Agrotis ypsilon ( Rottemburg ) can be influenced by a number of factors. The effects of feeding and mating behavior on the development of flight muscles, the structure of muscle fibres and mitochondria in flight muscles (dorsal longitudinal flight muscles) were observed using electron microscopy. By day 4 of the adult stage, the myofibrillar diameter, sarcomere length and myofibrillar volume fractions of hungry females were significantly less than those of feeding females. The myofibrillar diameter, sarcomere length and myofibrillar volume fractions of 7-day-old females without food were not significantly different from those of 4-day-old feeding females, but their myofibrillar diameter was significantly longer than those of 7-day-old females with food. 10 days after emergence, the sarcomere length of hungry females was significantly different from that of feeding females, and myofibrillar volume fractions and mitochondria volume fractions were both significantly lower than those of feeding females. Myofibrillar diameters of mating females 7, 10 and 13 days, respectively, after emergence were significantly smaller than those of unmated moths of the same ages. Myofibrillar volume fractions of mating females 7, 10 and 13 days after emergence were significantly less than those of unmated moths. Although mitochondria volume fractions showed no differences between these two groups at these ages, those of mating moths were significantly lower as early as 4 days after emergence. These results show that flight muscles of feeding females begin to degenerate after 4 days, and that hunger affects the development of flight muscles, preventing their degeneration in more mature moths but promotes their degeneration at the end of adult life. Mating also promotes degeneration of flight muscles.