The distribution of wheat curl mite (Aceria tosichella) lineages in Australia and their potential to transmit wheat streak mosaic virus

The wheat curl mite (WCM), Aceria tosichella, is an eriophyid pest of cereals, and the vector responsible for the transmission of wheat streak mosaic virus (WSMV). In a previous study, the taxonomic status of A. tosichella in Australia was assessed using molecular markers. A. tosichella was shown to consist of two genetically distinct lineages likely to represent different species. Here we show that both lineages occupy similar distributions, occurring throughout the entire Australian wheat belt, and that the lineages are often found in sympatry. CLIMEX analysis suggests that tolerance to heat and desiccation limit the distribution of A. tosichella. In the laboratory, only one WCM lineage transmitted WSMV virus under controlled conditions. These results have implications for the management of WCM and WSMV within Australia.