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

Insecticide resistance in RLEM

RLEM is a major pest affecting crops and pastures across southern Australia. Chemical pesticides available for their control are decreasingly effective due to the evolution of resistance. Insecticide resistance in RLEM is increasing across southern Australia and resistance to both pyrethroids (SPs) and organophosphates (OPs). It is now widespread across Western Australia and since 2016 has been confirmed in multiple populations from South Australia and in Victoria.

Free resistance screening service

Cesar Australia is offering a screening service to test for insecticide resistance in RLEM within South Australia, Victoria, NSW and Tasmania. The screening is at no-cost for Australian grain and pasture seed growers and advisers, thanks to funding by the Grains Research and Development Corporation (GRDC) and additional co-investment from AgriFutures Pasture Seeds Program.

Cesar Australia is particularly interested in hearing from growers or advisors who have had noted recent or past failures or have paddocks that are frequently impacted by the mites, and often require spraying.

The service will not only help detect any resistance before it becomes 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. If required, a collection kit is also available with the necessary equipment to send mites in for screening.

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

For more information on redlegged earth mite see Pestnotes and RLEM management tools webinar