Climate change also threatens insects

Climate change has already, and will in the future, have a significant impact on insect populations on the planet, and we absolutely must be concerned about the repercussions that this could have, warns an international consortium of more than 70 scientists.

“(Insects) are very vulnerable a priori due to their biology, said one of the signatories of the summary article published in the journal Ecological MonographsProfessor Jacques Brodeur of the Department of Biological Sciences at the University of Montreal.

“We observe impacts at the level of their physiology, their behavior, their distribution in space, at the level of their abundance as well. There are several major studies that have been published in recent years that report a decrease in the diversity and abundance of insects on a planetary scale. »

Insects, it is necessary to remember, are essential to the pollination of crops. They also serve as food for many animal species and are therefore “a pillar of our diet,” added Mr. Brodeur, who is also a researcher at the Institute for Research in Plant Biology at UdeM.

Their disappearance, or even simply a reduction in their number, could have unimaginable consequences on the stability and functioning of ecosystems, for example with regard to the control of harmful species.

Due to their small size, and since they are unable to regulate their body temperature, insects are among the first to be affected by a warming climate or by all other aspects associated with climate change, such as temperature and humidity, said Mr. Brodeur.

But the impacts of climate change on insects will not be entirely negative, he stressed.

“It’s not all black or all white,” said the researcher. There are insects that will benefit from global warming. For example, in Quebec, the growing season is going to be much longer, it is already longer than in the past, so there are insects that will be able to have perhaps one or two or even three more generations per year. . »

Some insects will move “towards the North, towards certain altitudes, which will therefore have a larger territory to exploit”, he added. Their presence in areas where they are not currently found could, on the other hand, contribute to the spread of diseases dangerous to humans.

Everything will ultimately depend on the context, said Mr. Brodeur. “But in general, what we’ve started to observe and what the models predict is that it’s still going to have a major negative impact on a lot of groups of insects,” he said.

He cites as an example the locust Melanoplus borealis, which currently colonizes the tundra at the top of several mountains in the Chic Chocs, in Gaspésie, including Mount Albert. As global warming causes the permafrost to thaw, he explains, all the fauna and flora associated with it, from this cricket unknown to the general public to the majestic caribou, risk disappearing.

“It’s a species that has no direct impact on human activities in agriculture or others, but it’s still a species that will disappear from the Quebec landscape in the medium term, at least at altitude, because it finds itself in an environment that is extremely threatened by global warming,” explained Mr. Brodeur.

“It is an emblematic species, but it is a species that will clearly suffer, even disappear in the face of climate change, but it is one among thousands. »

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