Scientists genetically modify insect

Diamondback moths targeted Goal to reduce destruction by harmful pest

A British company has pioneered a way to create a sterile male diamondback moth that it hopes will reduce the destruction caused by the harmful pest.

Oxitec scientists have genetically modified the diamondback moth to create sterile male insects that mate with wild females of the same species. The genetic modification prevents females in the following generation from surviving to adulthood.

In a news release, Oxitec scientists said transforming the pest is only the first phase of the research. More work is needed to develop and evaluate the project.

Alberta entomologist Scott Meers said the work is interesting, but 
he doesn’t know how it could be adapted across Canada’s vast canola acres.

“If it’s anything like other sterile male releases, it’s really, really expensive. It wouldn’t make sense on our extensive canola crops,” he said.

Sterile male releases are often used in controlled settings such as greenhouses rather than being released in fields.

Meers is unsure of the economic impact of diamondback moths on Canadian canola crops. The severity of infestations in Canada is often difficult to predict because it depends on over wintering populations in the United States and strong south winds that carry the moths north into Manitoba, Saskatchewan and eastern Alberta.

The moth can cause millions of dollars in damage when conditions are right as the larvae feed on the tender green canola and mustard leaves.

Cool, wet weather helps control adult activity and can drown the small larvae.

Parasitic wasps attack the moth in western Canada, and insecticides also control larval populations.

Jim Broatch, with Alberta Agriculture’s Pest management branch said he doesn’t know how effective a sterile diamondback moth release would be because most of the moths are blown in from the U.S.

“When would you would release the males? I guess you could figure out in advance. I am not sure how successful it would be or how many you would need to release to impact the population,” said Broatch. “We don’t know how many are going to be blown up.

Sterile male release of the coddling moth in Okanagan apple orchards has been quite successful, but is done in a limited area.

”It would be a tough one to figure out in how much to invest and how much you would benefit from it (in field crops),” said Broatch.