Ultrastructure of salivary glands in Psammotettix alienus Dahlbom (Homoptera: Cicadellidae) infected with Taastrup virus

Taastrup virus (TV) is a novel virus belonging to Mononegavirales and with filovirus-like morphology. In adult Psammotettix alienus infected with TV, the highest concentration of virus particles was found in salivary glands, consisting of a principal gland (type I-VI-cells) and an accessory gland. Examination of thin sections revealed enveloped particles, about 1300 nm long and 62 nm in diameter, located singly or in paracrystalline arrays in canaliculi of type III- and IV-cells. In gland cells with TV particles in canaliculi, granular masses up to 15 micrometer in diameter are present in the cytoplasm. These masses are believed to be viroplasms, the sites for viral replication. TV particles were observed at the connection between a canaliculus and the salivary duct system.