Ultrastructure of the yeast-like endocytobiont in the brown planthopper, Nilaparvata lugens (Stal) (Homoptera: Delphacidae)

Ultrastructure of the endocytobiont in the brown planthopper, Nilaparvata lugens (Stal), was observed by scanning and transmission electron microscopies. The symbiote is bacilliform, ca. 2.5 x 8-10 mu m in size and has a two-layered cell wall, the outer layer 33 nm and the inner 120 nm. It reproduced by budding, forming a convexity at the budding site. Transmission electron micrographs showed a large nucleus, ribosomes, rough endoplasmic reticulum, Golgi apparatus, and many mitochondria in cytoplasm. The degenerated symbiote had loose cytoplasm and dissociated cell wall. The present evidence verified that the symbiote in N. lugens resembles yeast.