Host range and geographic distribution of pangola stunt virus and its planthopper vectors in Australia

Abstract

Natural hosts of pangola stunt virus (PaSV) in eastern Austalia were found to be Digitaria eriantha ssp. pentzii (pangola grass), D. ciliaris (summer grass) and D. milanjiana. Transmission tests using the planthopper vector, Sogatella kolophon, showed that D. polevansii, D. eriantha ssp. eriantha, D. swazilandensis and the Australian native, D. divaricatissima were also susceptible, whereas D. didactyla was not infected. In tests of 22 species in 15 other genera, only Urochloa panicoides (annual urochloa grass) was infected. In field surveys, PaSV was commonly found in pangola grass in near-coastal districts from Grafton, N.S.W. to Walkamin, N. Qld and was detected up to 100 km inland at Toowoomba. The virus was not detected in either pangola grass or D. eriantha ssp. eriantha in subhumid areas west of Toowoomba or at Gayndah. Sogatella kolophon was collected from Bamaga, N. Qld to Murwillumbah, N.S.W. It was commonly associated with both PaSV-infected and PaSV-free digitgrass pastures. It is concluded that PaSV poses a threat to many digitgrasses in near-coastal districts of Qld and subtropical N.S.W., but so far is unknown in inland Australia.