Climate | New insects are causing havoc in Quebec

(Montreal) New insects regularly appear in Canada and some of them can pose a threat because they attack crops.

Several organizations are keeping a close eye on these potential pests, which can cause millions of dollars in damage in agriculture. Last month, the Canadian Food Inspection Agency (CFIA) issued a recall for the spotted sunflower, an insect that originated in Asia but has been well established in the United States since 2014.

In Quebec, the Ministry of Agriculture, Fisheries and Food (MAPAQ) also monitors harmful insects. This is in particular the role of the Phytosanitary Warning Network (RAP), which is under the responsibility of the MAPAQ’s Phytoprotection Department and which monitors the presence and evolution of crop enemies, whether they whether new or well known.

“A warner deals with a crop or a group of crops, for example berries, potatoes, etc. When there is an exotic insect that is likely to arrive in a crop, we join forces with these networks to carry out targeted screenings on these pests,” explains biologist-entomologist Jean-Philippe Légaré, who works at the Expertise Laboratory. and diagnosis in phytoprotection of the MAPAQ.

On the laboratory side, monitoring new species is part of the habits, whether insects that come from elsewhere or local species that become more problematic, according to Mr. Légaré.

“In recent years, with international trade, then probably climate change, there are definitely more and more risks associated with [ces] species, he explains. Add to that the fact that we have cultivars that can be grown further north […], pests follow these crops too. »

The arrival on the American continent of the spotted fulgore, this brightly colored insect which looks like a butterfly, but is not one, since it belongs to the order Hemiptera, like aphids and bedbugs, is d a consequence of international trade.

“Its spread over long distances is facilitated by human transport of infested material or objects containing egg masses”, can be read on the IRIIS phytoprotection website, managed among others by the Laboratory of Expertise and phytoprotection diagnosis.

Its presence in New York State, just 45 km from the Ontario border and the Niagara wine region, therefore suggests the risk of its imminent arrival in Canada.

By feeding on plant sap, the spotted sunflower can cause significant losses in vineyards as well as in fruit and forest crops.

For the moment, both the CFIA and the MAPAQ are betting on raising awareness — posters have been put up at rest stops, for example, so that people returning from the United States check for the presence of the insect on their vehicle.

“Normally, we will put traps in places where the risk of introduction is the highest. In this case, we would have put it in the vineyards close to transport routes. Except for [le fulgore tacheté]there is currently no capture method that allows you to [le] trap,” says Mr. Légaré.

The potential role of climate change

While entomologist Jean-Philippe Légaré finds it difficult to measure the impact of climate change on the presence of new pests, certain climate changes still play a role.

“The milder winters we have had in recent years can help especially in terms of winter survival, then that is true for exotic insects and for native insects. We see it in certain pests, as soon as there is a milder winter, the populations in the spring are higher,” he observes.

Longer summers are also appreciated by insects, which are cold-blooded animals whose metabolism is influenced by temperature.

“For example, if an insect in the past produced one generation per year, today there are certain insects which are capable of producing two generations, which will produce two egg stages during the year”, he explains. -he.

Climate change is already being observed in agriculture, and particularly in viticulture. Geographer Frédéric Lasserre, who has notably studied the development of Canadian vineyards and the impact of climate change, observes a warming throughout Quebec.

“There is very clearly an increase in the number of degree-days accumulated over the course of a year. This means that during the growing season – from spring until harvest, the heat has increased, which allows faster and more efficient maturation of most vines”, explains the professor at the department. in geography from Laval University.

These temperature changes come with their share of adaptations. On the one hand, we can consider the planting of new grape varieties in Quebec as well as further north in the province, but on the other hand, this comes with certain risks. Milder winters, for example, could jeopardize the production of icewine.

“There is also the biological risk. With the warming, a certain number of parasites and diseases are coming to Quebec that did not exist until now, from which we were protected thanks to the cold temperatures in winter”, indicates Mr. Lasserre.

In crops other than vines, the arrival in Quebec of an insect a few years ago could “probably” be linked to climate change, milder winters and a longer growing season, notes Mr. Légaré. .

“In 2018, the squash borer, [qui] has always been a pest of importance in most cucurbit crops in the United States, has [été] detected for the first time in Montérégie, then, since then, the populations have spread over all the cucurbitaceous producing regions in Quebec”, indicates the entomologist.

The larva of this butterfly burrows into the stems of squash and melon plants to feed on them, causing them to wilt.

Studies to adapt

To better understand the insects that affect Quebec crops, projects have been set up to study them. This is the case for strawberry pests, whose economic benefits are significant, Quebec being the first producing province in Canada.

Since last year, the team of Professor of Phytopathology Edel Pérez Lopez from Université Laval has been studying leafhoppers in strawberry cultivation and their role as vectors of viral and bacterial diseases as part of the Innov program. ‘Action agroalimentaire du MAPAQ and with the support of Mitacs.

“We found a lot more insects and that there are also a lot of insects that are completely new to the province, or even all of eastern Canada. [Ils] can transmit different bacterial and viral diseases”, generally observes Mr. Pérez Lopez.

In particular, he looked for the species of leafhopper that transmits the green petal disease that affects strawberries, since 20 cases have been identified this year, compared to 23 in 10 years.

Of the forty species identified, 11 are “completely new” to the province, according to Mr. Pérez Lopez.

By studying leafhoppers, the professor and his team at the Edelab laboratory hope to better understand how they work and propose means of control to the agricultural producers with whom they work. The main objective would be to reduce the quantity of insecticides — by using them better — and to develop biological control methods.

The first conclusions are expected by the end of the year.