Abstract

Anguina australis Steiner, a leaf gall nematode of Ehrharta longiflora Smith (annual veldtgrass) common in Western Australia (WA), was examined for its ability to act as a vector for Rathayibacter toxicus (Riley & Ophel) Sasaki et al., the bacterium responsible for various grass toxicities, including annual ryegrass toxicity in WA. The receptiveness of juveniles of A. australis, Anguina microlaenae and Anguina tritici to adhesion by a range of strains of R. toxicus and related species was tested in vitro. R. toxicus was the only species to adhere to A. australis juveniles. Inoculation of E. longiflora plants with A. australis and R. toxicus-infected galls from Lolium rigidum Gaudin resulted in bacterial colonisation of a proportion of galls formed. R. toxicus was isolated from these galls and bacterial inhibition assays indicated that toxins had been produced. It is concluded that A. australis is a vector for R. toxicus and that infested E. longiflora in WA may pose a risk to livestock.