This text is part of the special Acfas awards
Overall, the quantity of synthetic pesticides sold in Quebec has changed little for 15 years, according to a report from the Ministry of the Environment and the Fight against Climate Change published last June. Sales of glyphosate – classified as a “probable carcinogen” by the World Health Organization in 2015 – even increased steadily between 1992 and 2019.
If it is not sufficient for the moment to replace all synthetic pesticides, biological control constitutes an interesting option in certain cases. “This method aims to use living organisms, such as parasites, predators and pathogens such as bacteria or fungi, to attack a population of undesirable organisms without causing the negative effects of pesticides”, indicates Jacques Brodeur, professor at Department of Biological Sciences at the University of Montreal and holder of a Canada Research Chair in Biological Control.
A proven method
This approach poses two challenges: finding an effective natural warrior against the pest species, but above all ensuring that it does not in turn become a problem. An emblematic case occurred in Hawaii in the XIXe century. To fight against the rats that ravaged their sugar cane fields, producers have introduced the Java mongoose. Bad idea. Rats come out at night, while mongooses hunt by day. They have therefore rather set their sights on populations of ground-nesting birds, which they have decimated.
Fortunately, the methods have since been refined and the rules have tightened. “It has become very difficult to introduce exotic species into America, with good reason,” notes Jacques Brodeur, who has just won the Acfas Michel-Jurdant prize for environmental sciences. We need to clearly demonstrate to regulatory agencies that this species will act specifically on the problem we want to solve. “
[Le fort lobby des pesticides de synthèse] remains the biggest obstacle to the adoption of more natural methods
Biological control has proven its effectiveness in many situations. For example, in greenhouses, several insects are used to control aphids, while fungi and bacteria attack pests. “It helps to preserve the health of workers, because applying pesticides in closed environments presents risks,” says Jacques Brodeur. It also helps produce vegetables without pesticide residues. “
Memorable encounter
This nature enthusiast did a bachelor’s degree in 1984 at the University of Quebec at Rimouski, which had won him over with its flagship program in marine biology and oceanography. He had a life-changing encounter there when Jeremy McNeil, a prominent biologist, came to give a lecture on insects. “I quickly became an avid fan of entomology, insect ecology and pest control,” he recalls. Jeremy McNeil subsequently became its thesis supervisor.
Jacques Brodeur has since left his own mark in this field. It generated new knowledge about the complex interactions between plants, crop pests and their natural enemies. They have served to open up innovative avenues in the natural control of harmful populations. “I have always wanted to combine fundamental research and applied research, in particular to develop effective alternatives to synthetic pesticides,” he adds.
Present on several fronts
Among the achievements of which he is most proud, he cites his contribution to the fight against synthetic pesticides used for aesthetic purposes. These efforts led to the adoption in Quebec in 2003 of the Pesticide Management Code, which prohibits their use in urban areas. At the time, the case of a ten-year-old child from L’Île-Bizard suffering from cancer linked to a herbicide commonly used on golf courses and lawns in this neighborhood had greatly sensitized the population to this problem. .
In the 2000s, his research also calmed the panic that was gripping soybean producers in the face of the explosion of soybean aphids, a pest that came from Asia. By demonstrating that the predators already present in Quebec would be sufficient to regulate these aphid populations, he avoided the massive and recurrent use of pesticides. In addition to health and environmental gains, this has generated significant savings in this industry.
“Biological control offers effective solutions, which must be made known to producers,” concludes the researcher. In this effort to raise awareness and educate, however, we come up against a very strong lobby for synthetic pesticides. This remains the biggest obstacle to the adoption of more natural methods, ”he concludes.