Scientists have bred a genetically modified moth to reduce pest damages that affect crops such as kale, cabbage and broccoli. They described the technique as a pesticide-free and environment-friendly way of controlling damaging insect pests.

The researchers developed diamondback moths (Plutella xylostella) with a "self-limiting gene" that can significantly reduce populations of these invasive species as shown in greenhouse trials. The technique was already tested against dengue-fever causing mosquitoes, and this has caused their number to drop by more than 90 percent in trials conducted in Panama, Brazil and Cayman Islands.

The diamondback moth, which targets cruciferous vegetables, is one of the worst insect pests in the world. Researchers said that the insect costs farmers around the world up to $5 billion per year. Entomologist Tony Shelton, from Cornell University, said that conventional and organic pesticides cannot control these moths.

With the technique used by researchers from Oxitec, an Oxford University spinout company that pioneers in insecticide-free methods to control populations of pest insects, the moths produce female offspring that do not survive to reproduce so their population is controlled.

For their study, which was published in BMC Biology on July 16, Shelton and colleagues genetically engineered male moths capable of mating just as well as their non-GM counterparts, only these produced male offspring.

By conducting greenhouse trials, the researchers found that releasing the Oxitec diamondback moths into the population could crash the population of the insects in as little as eight weeks.

"We conclude that, subject to field confirmation, MS insects offer an effective and versatile control option against P. xylostella and potentially other pests, and may reduce reliance on and protect insecticide-based approaches, including Bt crops," the researchers wrote in their study.

Shelton and colleagues said that, unlike the use of insecticides that have unwanted effects on other insects such as bees, the approach is species-specific and only affects the targeted pest. Because the self-limiting gene is non-toxic, birds and animals that eat the moths are not harmed.

"This research is opening new doors for the future of farming with pest control methods that are non-toxic and pesticide-free," said study researcher Neil Morrison, from Oxitec. "We all share an interest in safe and environmentally friendly pest control, so this is a very promising tool that could be put to good use by farmers as part of integrated pest management (IPM) strategies for healthy and sustainable agriculture."

Photo: Fyn Kynd | Flickr 

ⓒ 2021 All rights reserved. Do not reproduce without permission.