Histological and Histochemical Observation of Intracellular Yeastlike Symbiotes in the Fat Body of the Smaller Brown Planthopper, Laodelphax striatellus (Homoptera : Delphacidae)

Abstract

Yeastlike symbiotes were observed in some cells (mycetocytes) of the fat body in the smaller brown planthopper, Laodelphax striatellus. The symbiotes were oval-shaped, about 13μ in length and seemed to propagate by budding. They had a FEULGEN positive nucleus, and were positive to RNA and protein reactions and were strongly stained by PAS reaction. They increased in the mycetocytes with nymphal development, and large number of them was observed in female adults while the male adults did not possess so many of them. They yeastlike symbiotes moved into the primary oocyte from the posterior pole through the epithelial plug of the ovary in female adult. At the late stage of embryonic development of the next generation, the symbiotes entered the fat body of the abdomen. The mycetocytes had no proteinaceous spheres and had less lipid droplets than the fat body cells.