Winter Vs. Insects

Bugs aren’t showing their face yet, but it won’t be long. We’ll be able to see how the efforts to manage these pests went come Spring. PJ Liesch the director of the UW-Madison Insect Diagnostic Lab and state entomologist, also known as the Wisconsin Bug guy says this winter didn’t impact insects too much. He shares how the winter affected emerald ash borer and ticks and what pests we should be aware of moving into spring.

“We’ve had emerald ash borer in the state for about 15 years so in terms of how it’s been progressing, it’s relatively slow,” says Liesch. “What does this mean for us? The winter didn’t impact the population and we will still be dealing with them, especially in the southeast corner of the state.”

There is some research being done in biological control of this insect. This has included screening for tiny stingless wasps that parasitize the eggs or larval stages. Liesch says it will be a few years yet but these wasps may help to turn the tide of the emerald ash borer population.

“If you’ve seen them killing your trees in your yard, I want to point out that those trees can become very hazardous,” adds Liesch. “If you have these trees around your home or in your woodlot you use for hunting, I’d suggest taking them down sooner rather than later.”

According to Liesch we can expect a normal year of ticks and mosquitos as the winter did not deter their populations. They have been insulated in the ground and with the decent snow cover we’ve had, they have been further protected from extreme temperatures. He says we may only think of ticks during the spring to fall months, but you can bump into ticks anytime of the year so it’s important to still keep an eye out if hiking.

When it comes to beneficial insects, over the last few years fireflies were knocked down to a certain extent.

Liesch adds, “Fireflies are actually predators of creatures like slugs and the larval stage of the fireflies. They do really well when we have damp conditions. I did have some reports the last year or two that folks weren’t seeing as many fireflies, and it’s due to weather patterns.”

One pest that Liesch says has been impacted by the weather is spider mites. They thrive under hot, dry conditions and he says the weather has really done some weird things with their populations, especially in southern Wisconsin.

One of the biggest insect stories of the year however is the spongy moth, previously known as the gypsy moth. This is a notorious defoliator of hardwood trees and does very well under dry conditions. Liesch has been monitoring these and says that based on trapping by the Department of Agriculture, there has been an increase in adults being trapped.

“This means that there are a lot of eggs out there and we could be in store for a heavy defoliation this year,” adds Liesch.

While these insects may be on the minds currently, he encourages people to also be aware of an emerging insect known as the spotted lantern fly. While this insect may not be in Wisconsin yet, it is still important to be aware of the impact it can have. The spotted lantern fly poses some risk for us here in Wisconsin in terms of agricultural impact, but also impact to yard and landscape trees. They feed on over seventy types of plants including fruit trees and grapes.

“It turns out that spotted lantern flies are really fond of grape plants to complete their life cycle and simply cause damage,” adds Liesch. “That’s a concern that I have, would be for our great vineyard industry here in Wisconsin.”