Soft options sell by Bernie Reppel

Dr Caroline Hauxwell about to pour some liquified Nomuraea-based bio-pesticide. Above: Nota tasty morsel: the remnants of heliothis caterpillars after being infected with the bio-pesticide.

WHEN Caroline Hauxwell saw the advertisement from Queensland's Department of Primary Industries (OPT) Biopesticides Unit, she thought the job was "written for me". She sought the opportunity to build on 20 years of pioneering bio-pesticide research by the retiring Bob Teakle.

The post was created under a Queensland Government! Agency for Food and Fibre Sciences initiative supporting 'green' industries. One focus was a world-first, successful attempt at regional management of heliothis - a GRDC-supported DPI project at Jimbour and Brookstead on Queensland's Darling Downs.

"Australian farmers now use 95 per cent of the Gemstar (viral bio-pesticide) produced in the United States," she says. "I think that's because Australian farmers, without subsidies and other forms of support, are forced to be more innovative." Resistance to chemical insecticides also intervened.

This Oxford grad is well placed to make her mark on bio-pesticide development. Over the years she's helped develop:

  • the bacterial insect control agent Bt (Bacillus thuringensis) with Novo Nordisc in Denmark
  • use of bio-pesticides and integrated pest management (IPM) against insect pests in cotton and grain in Central America -including IPM against cotton boll weevil
  • assessment of risk with genetically modified viruses, which became the basis of her doctorate.

And she's also worked with a variety of insect pathogens and virus controls, mostly in forestry, in Central America, west Africa and southern Asia.

Dr Hauxwell says while Australian farmers have readily adopted bio-pesticide technology - specifically Bt and Gemstar in integrated management "there's some concern, that over-reliance on just these two products may lead to resistance, especially to Bt," she says. "And, in the case of Gemstar, that supply may be limited because of manufacturing difficulties.

"There's also a growing awareness of the need for soft options, including biopesticides, against emerging pests like mirids, aphids and green vegetable bug" (not least because of the threat of resistance).

New products

She said a number of new bio-pesticides will be coming onto the market in the next few years. The product Vivus, manufactured in NSW by Australian Produced Biologicals, is being tested under permit while the University of Queensland and CSIRO scientists are working on in-vitro production heliothis virus which, if successful, should increase supply.

Both products are based on heliothis viruses similar to that in Gemstar and likely to have similar performance and use requirements. They need to be eaten to work, they take several days to kill the larvae and are most effective against small grubs.

They spread through pest populations without adversely affecting the beneficial insect predators and parasites.

Gemstar is based on a virus, and Bt on a toxin from a bacterium. Dr Hauxwell says the next generation of bio-pesticides is likely to come from the fungi group of insect pathogens.

Supported by growers and the Federal Government through the GRDC, the DPI Biopesticides Unit has been developing fungal bio-pesticides against heliothis.

Glasshouse assays so far show the most promising fungal bio-pesticide is based on Nomuraea rileyi, a native fungus isolated in North Queensland and specific to the Noctuid family of moths which includes loopers and armyworms as well as heliothis.

A prototype, Nomuraea-based bio-pesticide has been compared to Gemstar under field condition s, at different application rates, on a range of crops, at Biloela in Central Queensland, with promising early results.

"Beneficials (other insect predators) provide free pest control, mopping up survivors of other control measures and keeping pest pressure low," Dr Hauxwell says. "The lesson learnt from resistance to chemical insecticides is that there are no silver bullets.

"The eventual answer has to be use of bio-pesticides within a range of other soft options," Dr Hauxwell says.

Program 2.7.1 Contact: Dr Caroline Hauxwell 0738969362

Region North