Australia - Research delves into growing issue of insecticide resistance

Insecticide resistance in several broad-acre agricultural pests across southern Australia is being investigated through a research project supported by the Grains Research and Development Corporation (GRDC).

University of Melbourne researcher Dr Aston Arthur (photo) said the main focus of the project – for which assistance from grain growers and advisers is being sought – is to better understand insecticide resistance in pest mites and aphids.

"This is particularly important as resistance to insecticides is becoming more prevalent in these pests, with resistance detected recently for the first time in a number of important species,” Dr Arthur said.

"For example, insecticide resistance in redlegged earth mites to synthetic pyrethroids was first discovered in Australia only a few years ago on a property in Western Australia, and since then this resistance has spread across 15 different properties, spanning a distance of 450 kilometres.

"More importantly, this resistance in redlegged earth mites has been found to have a genetic basis where the resistance is passed on to future generations of mites, meaning it can potentially persist in the field indefinitely.”

In 2010 pirimicarb resistance was also detected for the first time in Australia in populations of green peach aphid.

"This is of particular concern to oilseed and pulse growers as this chemical has until now been seen as a fall back for aphid populations resistant to other chemical groups.”

The research is being undertaken at cesar (a science-based company that works with government and private organisations to develop and promote sustainable pest control strategies for broadacre cropping systems in Australia) and the University of Melbourne. It is being led by entomologist Dr Paul Umina, and will hopefully identify areas at risk and provide early detection of resistance populations.

Dr Umina said that to develop management strategies aimed at limiting the widespread development of resistance in these pests, a better understanding of the spread and frequency of insecticide resistance throughout cropping and pasture regions across southern Australia was needed.

In order to do this, assistance from advisers and farmers is being sought.

"We would like to hear from anyone who experiences chemical control difficulties or failures associated with pest mite species or aphids this season,” Dr Umina said.

"Even if growers or advisers know of a paddock with control failures in the past, they are encouraged to make contact.”

Any information obtained will be kept confidential, and assistance can be provided with recommendations for control if resistance is detected in any pest populations tested.

Source: Seed Quest