Insect Update: Fall Invaders And Autumn Plant Pests

Air Date:
Heard On The Larry Meiller Show

Larry Meiller learns about what fall insect invaders we should be watching for, indoors and out.

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  • Entomologist: How To Deal With Late-Summer Insect Invaders

    As summer winds down, people look towards fall and decide what they need to do to get ready for the change in seasons. Well, they aren’t alone. Insects are doing the same thing, according to a Wisconsin entomologist, and one of the best places to wait out a Wisconsin winter is in a house.

    According to entomologist Phil Pellitteri, western conifer seed bugs, boxelder bugs and cluster flies tend to start congregating around Labor Day, and it’s much better to exclude from the house instead of trying to get rid of them after they’ve settled in. Pellitteri is a distinguished faculty associate emeritus and he recently retired as head of the University of Wisconsin-Madison Insect Diagnostic Lab.

    He said that especially if there is a history of those insects finding their way indoors, “it’s time to keep your eyes open.” He explained that the sooner a potential problem is detected and addressed, “the better chance you have of success in keeping them outdoors.”

    Exclusion is a good tactic. Pellitteri said that often the south and west sides of homes have the most problems. He added that it’s important to make sure that potential entry points are caulked or sealed so the insects cannot get in. Screening vents and plugging holes are good steps as well.

    Spraying can be effective, but Pellitteri said that it’s important to take those measures at the right time. That means spraying for cluster flies in early July, boxelders in mid-September and Asian lady beetles in late September.

  • With Grasshoppers Around, Learn 5 Facts One Should Know About Them

    Grasshoppers are thriving in Wisconsin right now, meaning there are plenty of late-summer opportunities to catch glimpses of the many species native to the state.

    Courtesy of Phil Pellitteri, entomologist, distinguished faculty associate emeritus and recently retired head of the University of Wisconsin-Madison Insect Diagnostic Lab, here are some facts you should know about these insects currently in abundance:

    1. The lack of rain is a boon for them.

    Pellitteri isn’t at all surprised that grasshoppers are faring so well right now — grasshoppers (also crickets) prefer dry weather, and Wisconsin has not had a lot of precipitation late in the summer this year.

    Pellitteri added that it generally takes two or three years of drought conditions or close to it to get a really significant build-up of grasshoppers.

    2. Wet summers can actually harm them.

    One of the greatest risks to grasshoppers during their life cycle is wet conditions during the hatching p. Pellitteri said that the timing of the hatch depends on when the soil warms up sufficiently, but that it’s generally in early June.

    If there is a significant amount of rain at that time, “they don’t do well,” he said. “The young nymphs flood, and get sick, and all kinds of things.”

    3. Wisconsin winters don’t faze them.

    Many people may assume that harsh winters like the one we had last season devastate insect populations — but in fact, for grasshoppers, that’s not the case.

    Grasshoppers, which produce one new generation per year, lay their eggs — which Pellitteri described as looking like a cluster of rice grains—in the fall. Those eggs hatch in the summer, and according to Pellitteri, they’re largely winter-proof.

    “The winter extremes don’t affect them much,” he said. “They’re down in the soil and protected.”

    There are also some adult species of grasshopper capable of overwintering, meaning that it’s possible to see adults in the springtime.

    4. In large numbers, they can be garden pests.

    Adult grasshoppers can fly, which Pellitteri said can make them into a pest quickly. But while they can do damage in the garden and on agricultural land, he said that they need to be in very high numbers to do so.

    “They need to really gang up on a plant,” he said. “We’re talking 15 or 20 on a corn stalk before you see significant problems.”

    Pellitteri said that to judge if it is going to be a problem, looking at the population density will help: “Five to 10 per square yard is getting pretty serious,” he said.

    5. They are prone to eat anything.

    Pellitteri said that grasshoppers are considered general feeders, meaning that they will eat what’s available. Oddly, he said that they have been known to chew through plastic screens and even eat the paint off houses.

    “Nutritionally, it doesn’t make any sense,” he said, “but that doesn’t mean that they don’t do it.”

Episode Credits

  • Larry Meiller Host
  • Judith Siers-Poisson Producer
  • Phil Pellitteri Guest

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