While its leader, Dave Murray, insists drought and other factors have had a bit to do with it,  a three year project researching the management of Heliothis on Queensland’s Darling Downs has paid excellent dividends back to graingrowers.

Conventional “hard” insecticides have virtually disappeared from grain sorghum paddocks, reducing the insecticide burden on the environment, eliminating the prospect of residues in stockfeed supplies and contributing to a “clean and green” industry image by conserving biodiversity. 

Growers are more confident about their ability to control insect pests, community objections to insecticide use are conspicuous by their absence and neighbours are getting along better than they used to not so long ago.

Dr Murray leads a Queensland Department of Primary Industries and Fisheries (QDPI&F) team that’s been involved in a number of Cotton and Grains Research and Development Corporation (CRDC/GRDC) supported projects targeting heliothis, one of the world’s worst crop pests.

The team and its various projects brought Area Wide Management, Integrated Pest Management and Insecticide Resistance Management approaches to one of Australia’s most intensively cropped farming areas.

In the project’s final report to the GRDC on the project “Heliothis Management in south Queensland farming systems”, Dr Murray said all heliothis susceptible crops on the Darling Downs were “at the crossroads with regard to heliothis management when the project began three years ago.

“Given the history of insecticide resistance to Helicoverpa armigera, new chemical compounds could be expected to last less than 10 years in the absence of an Insecticide Resistance Management Strategy, and consequent overuse,” Dr Murray said.

“In the absence of our research into heliothis management, yields would have declined and costs of production increased, making some crops unprofitable and non-viable.

“Increased awareness and knowledge amongst graingrowers and their advisers of heliothis management, within the context of Area Wide, Integrated Pest and Insecticide Resistance Managements, have delivered improved management, with less reliance on conventional disruptive insecticides.”     

Dr Murray said an analysis of the benefits of Area Wide and Integrated Pest Management in the cotton industry had estimated their total value at $250 million.

New insect control campaigns rattle an old enemy

GRDC Crop Doctor

You’d never have imagined it a decade ago, the range of innovative approaches taken by entomologists and collaborating farmers to insect control in recent years, all designed to be more effective and environmentally friendly at the same time.

Some of the best results have come from a partnership between a team from Queensland Department of Primary Industries and Fisheries (QDPI&F) and the Grains and Cotton Research and Development Corporations (GRDC/CRDC). 

The corporations invested in a number of research projects by QDPI&F, focused primarily on control of heliothis, which costs Australia’s farm industries between $200 and $300 million a year in crop damage and control measures.

As the projects progressed, the Queensland entomologists developed strategies for Integrated Pest Management, Area Wide Management, Insecticide Resistance Management and Best Management Practice and saw them win general acceptance on the Darling Downs.

The team, which won the GRDC’s 2004 Seed of Light award for science communication in the northern region, looked at many ways of improving heliothis control,  including:

• encouragement of in-crop “beneficials” – natural predators, parasites and diseases that attack heliothis,

• promotion of the development, registration and grower adoption of more selective bio-pesticides like nucleopolyhedrovirus (NPV) and Bacillus thuringiensis (Bt),

• collaboration with chemical companies and industry on the commercialisation of “softer” insecticides like Steward and Tracer for different crops, and ways of preventing development of heliothis resistance to them,

• use of trap crops for heliothis and refuges for “beneficials”; a roadside verge in the Brookstead cropping area was investigated for its value as a refuge for heliothis predators and parasitoids, but they were found only in low numbers;

• incomplete development of damage thresholds in chickpeas, looking to set the degree of heliothis damage which growers might tolerate without significant yield loss, and

• video analysis of predators of heliothis larvae in maize, mungbeans, sorghum and cotton, with the surprising identification of mice as major consumers of the large grubs.