Abstract
Nymphs and adults of Anomoneura mori harbor two kinds of symbiotic microorganisms in their mycetome. Vegetative forms of symbionts are enveloped by a triple-layered membrane and contain many ribosomes and dense granular masses which could be some genetical material, but have no filamentous nucleoid structure as in the usual bacteria. They proliferate rapidly during nymphal development of the host insect, then decrease in number during the abeyance period of the ovarian development in the female adult ranging from early summer to winter, and again resume their proliferation during the postwinter developing period of the ovary. Then they leave the mycetome for hemocoel as infectious forms, reaching the calyx region of the ovariole. There they are engulfed by the phagocytic action of the ovarian follicle cells and gather to form a spherical aggregation at the basal end of the ovum, thus being transmitted transovarially to the next generation of the host insect.
