Cotton fields monitored for insecticide resistance

Cotton bollworm

Cotton bollworm

The cotton industry has again contracted the NSW Department of Primary Industries (DPI) to monitor the incidence and causes of insecticide resistance in the major pest of cotton, the cotton bollworm.

The three-year $550,000 research project, for the Cotton Research and Development Corporation (CRDC), involves annual monitoring of insecticide resistance in Helicoverpa armigera and to a lesser extent H. punctigera.

Project researcher, Dr Louise Rossiter, said the aim is to detect the development of resistance before it reaches a level where crops start to fail.

“Effective resistance management relies on collecting data on the susceptibility of insects, accurate monitoring of resistance levels and a knowledge of the genetics and mechanisms of resistance.

“Without this information, resistance cannot be accommodated for until it is present in the field at a level where sprays start to work less effectively and become a major cost to the industry as a whole.”

To control resistance already present in insects - and to minimise it from developing further - the cotton industry currently follows a voluntary insecticide resistance management strategy (IRMS).

This strategy incorporates the major pests of the cotton industry: Helicoverpa species, aphids, mites and whitefly.

The monitoring of Helicoverpa species will occur in conjunction with research into resistance mechanisms being undertaken by Dr Robin Gunning from DPI Tamworth.

Dr Rossiter said together the DPI research will help the cotton industry to continue to increase its knowledge of the incidence and mechanisms of insecticide resistance, and hence develop effective resistance management strategies.

“The long term sustainability of effective chemical pest control relies on this information.

“More effective and reduced pesticide use lowers the costs involved in pest control and reduces environmental contamination, with benefits for the community as a whole”, she said.

Resistance to insecticides has been a major issue in the cotton industry since pyrethroid resistance was detected in 1983.

“Since this time the cotton industry has been proactive in managing chemical use in cotton, as there are significant costs associated with resistance as a result of increased spraying and chemical costs”, Dr Rossiter said.

Further information

Dr Louise Rossiter, NSW DPI, Narrabri on 02 6799 2428 or louise.rossiter@dpi.nsw.gov.au.