Summary

Bluegreen aphids (BGA; Acyrthosiphon kondoi) are a major pest of lucerne and other legume crops. Traditionally, growers have successfully used insecticides to control BGA populations. However, multiple growers have recently reported insecticides failing to control BGA populations. Our preliminary testing suggests these populations may have evolved resistance to at least one organophosphate insecticide. Here, our project will examine whether multiple BGA populations have evolved insecticide resistance and communicate our results to growers and other industry stakeholders. To do so, we will leverage three BGA populations (one from NSW and two from SA) that we have recently received from lucerne crops following insecticide control failures and a historically collected BGA population that we know lacks resistance. Through multiple laboratory bioassays, we will examine the dose-response of field populations to organophosphates and carbamates and compare this to our reference susceptible population. We will also explore whether gamma-cyhalothrin – a synthetic pyrethroid registered for other aphid species – can provide an alternative insecticide to control BGA. Should we detect resistance in BGA populations, we will undertake preliminary investigations of mutations in the target gene of organophosphates (acetylcholinesterase – ace) within populations as a way to explore the heritability of resistance. Based on our findings, we will provide AgriFutures with recommendations on how growers can manage insecticide-resistant BGA and future RD&E to enhance long-term BGA management. We will communicate our findings and recommendations with growers and other industry stakeholders through the wide-reaching networks of Lucerne Australia.

Program

Pasture Seeds

Research Organisation

Cesar Pty Ltd