This season, grain growers in the southern cropping region can access a free-of-charge service to determine whether redlegged earth mite (RLEM) populations within their crops are resistant to insecticides.
Knowing the resistance status of RLEM populations will assist growers in implementing appropriate and effective insect management strategies.
The RLEM insecticide-resistance testing service is being made available to growers and their advisers through a national Grains Research and Development Corporation-funded project led by the University of Melbourne in collaboration with cesar, the Department of Agriculture and Food, Western Australia (DAFWA), CSIRO and the University of WA.
The resistance testing service is part of a three-year GRDC-funded investigation into resistance in RLEM, which has already led to recommendations about insecticide resistance management and improved chemical control methods.
While there are no confirmed cases of resistance in south-east Australia as yet, resistance to synthetic pyrethroids (SPs) has been confirmed in large populations of RLEM in WA, where some populations have also developed resistance to organophosphates (OPs).
The overuse of chemicals is fast-tracking resistance in RLEM, according to Dr Paul Umina, from cesar and the University of Melbourne.
Dr Umina says insecticides should be used in a responsible manner to avoid resistance occurring in the southern cropping region (Victoria, South Australia, Tasmania and southern and central New South Wales). In addition to resistance developing, there is also a genuine possibility of resistance spreading from WA into eastern states.
Identification of the gene mutation responsible for pyrethroid resistance has enabled researchers to devise a high-throughput, DNA-based test for SP resistance in RLEM. Mites can also be tested for resistance to OPs using laboratory chemical bioassays.
"By using these services in 2015, there is an opportunity for growers to know what is happening in their paddocks in terms of insecticide resistance," Dr Umina said.
Growers who have experienced chemical control failures or suspect they may have resistant mites are strongly encouraged to take advantage of this free service.
For more information about how to access the testing service, contact cesar researcher Nick Bell (phone 0439 488 251 or email email@example.com) or Dr Paul Umina (phone 03 9349 4723 or email firstname.lastname@example.org).
In the mean time, growers and advisers seeking more information on identification and management of mites can download the GRDC Crop Mites Back Pocket Guide
Dr Paul Umina, cesar
03 9349 4723
Sharon Watt, Porter Novelli
Caption: Grain growers in the southern cropping region can access a free-of-charge service to determine whether redlegged earth mite (RLEM) populations within their crops are resistant to insecticides. Photo: A Weeks, cesar