The search for insect vectors of phytoplasma diseases in Northern Australian grasses

The discovery of phytoplasmas in three native grass species in wet dry tropical regions of the Northern Territory and Western Australia poses a potential threat to the Australian sugarcane industry. In Asia leafhoppers (Matsumuratettix hiroglyphicus and Proutista moesta) are known to transmit the phytoplasmas to sugarcane but to date those species of leafhopper have not been recorded in Australia. The results of a search for possible insect vectors of the diseases in northern Australian grasses are described. One leafhopper species, Chiasmus varicolor, collected from couch infected with white leaf disease tested positive for the associated phytoplasma and trials are being conducted to determine whether C. varicolor merely feeds on infected grass or is a possible vector (A).