A new point in history has been reached, entomologists say, as climate-led species’ collapse moves up the food chain even in supposedly protected regions free of pesticides
Reports of falling insect numbers around the world are not new. International reviews have estimated annual losses globally of between 1% and 2.5% of total biomass every year.
Widespread use of pesticides and fertilisers, light and chemical pollution, loss of habitat and the growth of industrial agriculture have all carved into their numbers. Often, these were deaths of proximity: insects are sensitive creatures, and any nearby source of pollution can send their populations crumbling.
But what Janzen and Hallwachs are witnessing is a part of a newer phenomenon: the catastrophic collapse of insect populations in supposedly protected regions of forest. “In the parts of Costa Rica that are heavily hit by pesticides, the insects are completely wiped out,” Hallwachs says.
In Central Florida, we were overrun in the Spring with Lovebugs, which were an invasive species. They had sticky, acidic guts which would stick to cars and ruin the paint. Every Spring, stores would have big displays of the liquid to add to your wiper fluid to remove the Lovebugs from your windshield.
Then they disappeared, nearly overnight. A few years ago, the Spring hatching was really light, and it’s been lighter each year. I saw one Lovebugs this year.
The weird thing is, scientists have no idea why, because there is no grant money to study it. They are an invasive species, so we want them to go away. Nobody is going to spend money to find out why.
In the case of Lovebugs, their eradication was a positive outcome, but whatever wiped them out, could wipe out bugs that we want to keep because they are important to the food chain.