With a fast approaching winter that’s already brought plenty of snow, bugs are probably the last thing on peoples minds.
According to University of Wisconsin (UW) entomology specialist PJ Liesch, however, there’s never an off season for insects.
“If it’s just warm enough, right around freezing or just above that, especially if you have maybe a little bit of open water, from a stream or something like that, you’d be surprised at how many different things you can find out and active,” he said.
Liesch, the director of the UW Insect Diagnostic Lab, recently spoke as part of the Science on Tap speakers series held in Minocqua, and he explained there are various spiders, winter scorpion flys, and snow fleas, right here in the Northwoods, that live through the winter.
In fact, he said insects can handle the climate of basically every part of the globe.
“About the only spots you don’t find insects would be out in the middle of the ocean and up at the North Pole where there’s nothing but ice,” Liesch said. “But just about every other spot you look, from the tops of mountains, to deep dark caves you can find insects if you go looking.”
At the UW Diagnostic Lab Liesch handles 2,500 insect identification requests every year, so he knows more than most how diverse an animal insects are.
He explained that out of the 1.5 million known animal species, insects comprise over a million of them. The beetle alone is so diverse that one in four animals on the planet is a form of a beetle.
“About 70% of the animals we know of are insects,” Liesch said. “They’re the overwhelming majority and yet they’re so small that they often go unnoticed.”
There’s a lot riding on the backs of the world’s little bugs, however, as insects perform some critical and noteworthy tasks.
First of all they are responsible for much of the planet’s decomposition.
“They’re behind the scenes recyclers breaking down organic materials,” Liesch said. “That could be animal material, that could be decaying plants, things like that. But they play a really important role in breaking down those materials and returning nutrients to the soil.”
As pollinators, bugs also provide the world with fruits and vegetables. Liesch said 75% of the crop species on the planet use insects as pollinators. Without them, the world’s diet would be drastically different.
“The grocery store would be a very different place,” Liesch said. “The produce sections would essentially be gone.”
In addition to producing food for people, bugs also directly affect the food web of basically everything else. By being the base of it. With a loss of insects, Liesch said, the structure of animal life would crumble.
“Life as we know it would just start collapsing because all the bigger things that eat insects and all the bigger things that eat those, they’re not going to have food,” he explained.
This is frightening to consider because in the modern world bugs are facing their fair share of challenges.
According to Liesch, insects are facing tough times due to urbanization, widespread pesticide use, deforestation, climate change, and light pollution.
And they must compete with invasive species.
“In a given year, on average, I see two to three new non native insets show up in the state every year,” Liesch said.
Some don’t have any effect at all. While others can do significant damage.
“Every once in awhile we’ll get the next emerald ash borer,” Liesch said.
He knows a thing or two about the emerald ash borer.
“That was kind of my gateway bug that got me into entomology,” he said. “That was back, it’s going on 15 years that I’ve worked with that insect in one way or another.”
He explained the insect has done significant damage to ash trees, mostly in southern Wisconsin, but that three-quarters of the state’s municipalities have still yet to see it.
As far as combatting emerald ash borer, Liesch said researchers are studying trees that have been attacked by the insect and have survived.
“There are some trees that show signs of being attacked and yet they survived. So perhaps they have a genetic mutation. Better plant defenses. Maybe they’re less detectable to the insect. We don’t fully know at this point,” Liesch said. “But folks are surveying those trees and perhaps a long term goal would be to take those trees that aren’t killed by emerald ash borer and breed some type of heartier tree that then could be planted to ensure that the ash trees aren’t all going to get wiped out.”
Another more direct technique to combat the emerald ash borer is biological control. Liesch explained that in some places, including Wisconsin, parasitoids which target only emerald ash borer have been released.
The parasitoids, which unlike parasites kill their host, are minuscule wasps.
“We’re still relatively early in the ballgame,” Liesch said. “We don’t know what’s that magical critical mass we need to hit before they start really knocking down emerald ash borer.”
Another major hurdle for today’s insects is a lack of diversity on the landscape, due to monocultures like the huge fields of modern agriculture.
And, according to Liesch, this is something everybody can do something about.
“Put up a diversity of plants,” he advised. “A lot of insects are picky eaters. The more diversity we have in terms of the plants around us, we’re going to be providing habitat for more of those insects.”
It was clear from Liesch’s speech that a better home for insects means the same for us.
Jacob Friede may be reached at [email protected] or [email protected]