Rapid postembryonic development of a cricket flight muscle

The metathoracic dorsal longitudinal muscle (DLM) of the cricket Teleogryllus oceanicus differentiated and developed rapidly over the last nymphal instar. Within eight days, the muscle mass increased by a factor of 15 and the relative volume of mitochondria quadrupled, while the relative amounts of myofibril and sarcoplasmic reticulum decreased. Tracheoblasts began to invade the muscle fibers immediately before the adult molt. Muscle mass continued to increase until four days after the adult molt, but the relative volumes of the ultrastructural components did not change. Within two weeks following the adult molt, the muscles in some of the animals began to degenerate.