Scientists take the guesswork out of biological controls

The art of pest management in cotton is becoming so sophisticated that a DNA diagnostic testing service has been set up to quantify the effectiveness of biological control tools.

The University of Queensland has joined forces with crop protection provider Cotton Growers Services to generate rapid feedback on the levels of infection of viruses and parasites that offer biological control of cotton pests.

In what is believed to be a world first, UQ`s Centre for Identification and Diagnostics within the School of Life Sciences is using DNA techniques to identify the species of grubs in the crop, and whether they have been parasitised by wasps or infected by viruses that will eventually kill them.

CID director Dr Dave Merritt said that within a matter of hours of receiving the insect samples, scientists can determine whether the "goodies" have infected the "baddies" and the pest battle can be won without the assistance of an application of chemical insecticide.

Cotton Growers Services development manager Philip Armytage said the level of insect infestation and effectiveness of biological controls are key variables in the cotton crop, and Australian growers are hungry for information and tools that enable them to fight nature with nature.

Under this joint-venture with industry, UQ scientists will fine-tune the techniques during what remains of this cotton season and be ready in November to provide a diagnostic service with a 24-hour turnaround.

Timing is crucial in managing insect pests in cotton, but the longer growers are able to hold off "calling in the big guns", ie using chemical insecticides, the better it is for the population of beneficial insects which provide biological control of the pests.

These diagnostics will also build confidence in biopesticides produced from naturally-occurring live viruses that cause a slow and steady demise of the pest population rather than the reassuring instant "knock-down" provided by chemical insecticides.

"If growers know that the grubs are, for example, 80 percent infected, then they can be confident that although grubs are still alive in the crop today, their infection will result in certain demise before they can do excessive damage to the crop," Dr Merritt said.

He said it was rewarding for the university to see the commercialisation of research that has been funded for many years by growers through the Cotton Research and Development Corporation and the Grains Research and Development Corporation.

During the fine-tuning phase, UQ will provide the scientific services to the partnership on a cost-recovery basis and plans the commercial hand over of the service to industry within two years, when testing devices can be operating in the major cotton growing regions of Australia. The DNA diagnostic tests are also expected to be useful in grain crops, such as sorghum and pulses.

Media: For further information, contact Dave Merritt (telephone 07 3365 3478) or Philip Armytage (telephone 02 6795 3100).