ULTRASTRUCTURE OF THE YEAST-LIKE ENDOCYTOBIONT IN THE BROWN PLANTHOPPER, NILAPARVATA-LUGENS (STAL) (HOMOPTERA, DELPHACIDAE)

Ultrastructure of the endocytobiont in the brown planthopper, Nilaparv ata 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 s ite. Transmission electron micrographs showed a large nucleus, ribosom es, rough endoplasmic reticulum, Golgi apparatus, and many mitochondri a in cytoplasm. The degenerated symbiote had loose cytoplasm and disso ciated cell wall. The present evidence verified that the symbiote in N . lugens resembles yeast.