Oct 14, 2005

Whitefly Resistance Technology DevelopedSource: Rothamsted Research

United Kingdom and Australian scientists have developed a technique that delivers a carefully timed double blow to insects that have evolved pesticide resistance. The new technology deactivates the resistance mechanisms of the pests, before exposing them to a pesticide. This invention is likely to have an impact on many agricultural sectors and especially in the third world, where resistance and excessive pesticide use are major problems.

Insecticide resistance in insect pests is becoming progressively more widespread and is a major limitation to crop production worldwide. Enzyme inhibitors, such as piperonyl butoxide (PBO) have the potential to overcome the resistance mechanism, but so far they have achieved little success in the field. Graham Moores, senior research scientist, Rothamsted Research, Hertfordshire, UK, and Robin Gunning, principal research scientist, NSW Department of Primary Industries-Agriculture, Tamworth, UK, have demonstrated that, when pesticides and inhibitors are applied simultaneously, the pesticide can be inactivated by the pest’s metabolic enzymes before the inhibitor has had a chance to act. Applying the inhibitor some hours prior to the insecticide can work, but it is not economic for farmers to make two applications.

To overcome this problem, the scientists, in partnership with Italian company Endura SpA, have developed a product that delivers two burst releases of chemicals. Novel formulation technology ensures that the enzyme inhibitor is released first, inactivating the pesticide-degrading enzymes that normally protect the pests. Four to five hours later, once the inhibitor has had time to act, the pesticide is released, killing the now vulnerable insect.

The technique has been successfully trialed in some of the world’s resistance hot spots. “We achieved 100 percent mortality of whiteflies in Southern Spain using pesticides that normally give no control, owing to the huge resistance problem in this area,” said Moores. “This product can restore efficacy to affordable pesticides, which is particularly important to third world farmers” .

The invention is targeted at pests with a metabolic mechanism of resistance to pesticides, such as cotton bollworm, whitefly, diamondback moth, aphids and mosquito species. It is applicable to resistant pests on food and non-food crops. UK and international patents have been applied for.