Pest mites are a significant threat to the establishment of grain crops. Some species have become more problematic over the last decade as farming practices have changed, while others are proving difficult to control due to tolerance and insecticide resistance issues. The recent emergence of resistance to synthetic pyrethroids and organophosphates in the redlegged earth mite (RLEM) is of particular concern to the Australian grains industry.
This project will lead to recommendations about insecticide resistance management and improved chemical control methods for RLEM. A key component of the work is the integration of field diagnostics made available to growers, broad-scale field surveillance and fitness studies, which will enable long-term management and monitoring guidelines to be implemented across western and southern Australia. This information will feed into Resistance Management Strategies that will include recommendations such as rotations of chemical classes, timing of pesticide application(s), controlling weed hosts and the use of insecticide seed treatments in order to minimize resistance development through the over reliance and ad hoc applications of insecticides.
The project will also investigate emerging resistance concerns in the lucerne flea and Bryobia mites. There appears to be a growing number of control difficulties in the field involving these pests, which in part is due to their inherent tolerance to certain chemicals. This project will optimize insecticide-testing methodologies, develop baseline sensitivity data and test field populations across Australia if/when chemical control failures are reported.