Canadians need to seriously discuss the new technique for controlling insect pests using genetic modification, scientists say.
Published yesterday at 12:05 p.m.
Bob Weber The Canadian Press
Their concerns are expressed in a new report from the Pest Management Review Agency, a branch of Health Canada that regulates pesticide use.
Experts say genetic modification could provide a powerful new tool as old insecticides become less effective and climate change leads to new infestations.
Such techniques are already being used in attempts to prevent mosquitoes from spreading malaria.
The report’s authors note that there are many unknown variables. They argue that the consequences of releasing synthetic versions of natural organisms could be harmful and lasting.
New Hope
The genetics of insect pests are being turned against themselves by scientists, altering the genomes of their known enemies in ways that offer farmers and doctors new ways to combat these pests.
This booming field offers new hope against old scourges like malaria. And it could provide brilliant new tools as well-known insecticides become less effective and climate change reshuffles the deck.
But concerns are buzzing around the new technology like a swarm of mosquitoes.
“Questions remain about the effectiveness of these tools, their safety and their relevance,” says a new report from the Council of Canadian Academies. Is it appropriate to use gene editing in the natural environment, and how does gene editing fit into the broader pest control toolkit? »
The report, released last week, was commissioned by the Pest Management Regulatory Agency, a branch of Health Canada that regulates pest control chemicals. It is the beginning of what the authors hope will be an urgent and thoughtful debate about the potential role of an entirely new method for eliminating these insects.
“Genetic pest control tools could radically change our relationship with the environment, not only because of their potential impact on the ecosystem of which we are a part, but also because of their challenge to the social and cultural values that influence decisions around them,” is to read there.
Resistance and climate change
Genetic pest control is being considered for several reasons, said co-author Mark Belmonte, a University of Manitoba biologist.
“Traditional pesticides are becoming less effective, either because insects develop resistance or, in my opinion, because communities are looking for safer alternatives,” he explains.
Climate change increases its own pressure.
“We have very cold winters and it’s great for insect control,” Belmonte said. Now we are experiencing a major change where cold spells no longer last as long or disappear altogether. We’re finding that insect populations are changing pretty quickly. »
Additionally, this technique reduces the use of chemicals and, unlike pesticides, heavily targets a single species.
Multiple strategies
Genetic responses to these challenges can either change a genome to sterilize the pest or change something else that makes it less effective, for example by reducing its ability to survive cold.
These two strategies can be used in two ways.
In one case, a modified population of sterile males is introduced in sufficient numbers to reduce and control an infestation. Modified insects should be reintroduced regularly.
In the other case, the insect is modified – perhaps with a modification that makes it susceptible to a chemical – so that its genome replaces the original in the overall population. The newcomer is becoming the new norm.
Humans have been modifying animals through selective breeding for centuries. But it appears to be new, said co-author Ben Matthews, a zoologist at the University of Manitoba.
“We are doing something fundamentally different,” he believes.
Breeding animals for desired traits provides years to evaluate their behavior and impacts. This would not be the case with an organism that was modified and released in a laboratory, Mr Matthews said.
Many people find the idea of “playing God” uncomfortable, he added.
In Africa, genetically modified mosquitoes are already being tested against malaria, a disease that killed nearly 620,000 people last year. The findings make a compelling case for further research, said Robert Slater, a professor of public policy at Carleton University and chair of the committee that wrote the report.
Little evidence
Canada is just beginning to discuss how to regulate genetically modified insects, Slater said. This won’t be easy.
“The regulatory system works on the basis of evidence. He has to weigh up what the risks are and what the benefits are. “This is a completely new technology and we have very little evidence,” he said.
Mr. Slater said he and his colleagues recommended a slow approach with many so-called “exit ramps.”
Small-scale field trials would allow regulators to learn how to work with local communities and provide much-needed data on impacts and benefits. More research is needed – as well as in other, often sparse areas.
“There’s a quality that everyone who goes into this science has to have,” Slater said. Humility. »