Free screening service to test for insecticide resistance in the redlegged earth mite continues for Spring 2023

Growers and advisors across Australia are being called on to send in samples of redlegged earthmite (RLEM) to help detect the spread of insecticide-resistant populations.

Cesar Australia is offering a free screening service to test for insecticide resistance in the RLEM within South Australia, Victoria, New South Wales and Tasmania. The screening service is at no cost for Australian pasture seed growers and advisers, thanks to co-investment by AgriFutures Pasture Seeds Program. This investment adds to a larger program funded by Grains Research Development Corporation (GRDC), enabling some research activities in grains systems to be extended to pasture seed producers.

The RLEM (Halotydeus destructor) is a major pest affecting the pasture seed industry, as well as many other pastures and cropping industries. The chemical insecticides that are available for RLEM control are becoming less effective due to the evolution of resistance. This is because of the heavy reliance on the three registered chemical groups to control the RLEM – synthetic pyrethroids (SPs), organophosphates OPs, and neonicotinoids.

Insecticide resistance in the RLEM is increasing across southern Australia. Resistance to both SPs and OPs is now widespread across Western Australia, and is present in several areas within South Australia, and Victoria. In the last year, the research team have detected a significant increase in insecticide-resistance in pasture seed paddocks within the south-eastern region of South Australia.

The project team are particularly interested in hearing from growers or advisors who have experienced recent, or past failures or have paddocks that are frequently impacted by the mites and often require spraying, or where mites are not being controlled by seed treatments.

This project will not only help detect any resistance before it becomes more widespread, but will also help identify the best control options for growers.

Cesar Australia will be undertaking field trips in the coming months to collect RLEM for resistance screening, so get in touch if you would like to discuss RLEM collection from your area. The target areas for this year’s resistance screening are New South Wales, the mid-north and south-east regions of South Australia and the Eyre Peninsula. A collection kit can also be provided containing the necessary equipment to collect and send mites in for screening if required.

For further information or to access the resistance testing service, please contact:
Dr Aston Arthur, Cesar Australia
0427 875 040