U. of I. Extension entomologist Phil Nixon has degrees from Lincoln Land Community College, Southern Illinois University, and Kansas State University. He has statewide responsibilities for pesticide safety education and the integrated pest management of landscape and household insect pests.
Given the weather we've experienced this summer in Central Illinois, is there any way to predict what sort of insect problems may arise next spring?
Most insects in Illinois are not greatly affected by the changes in the weather that we experience from year to year. Many of the insects that occur in Illinois are found from Atlanta, Ga., into central Canada, so they are capable of coping with what we consider to be severe and mild years. Although more insect pests survive mild winters, the insects that feed on and parasitize them also survive in higher numbers, resulting in little change the following growing season. We are at the edge of the range for only a few pests that benefit from mild or severe winters depending on whether we are the southern or northern edge of their range. The timely rainfall most of the state experienced this summer has probably increased fungal diseases of insects, causing a reduction of many insect numbers. Conversely, mosquitoes and other insects survive in higher numbers in wetter years.
Why haven't we seen as many carpenter bees, yellowjackets and ladybugs this year?
In my experience, carpenter bees have been more numerous this year than for many years. We are just getting into the time of year when yellowjackets become noticeable, so it is too early to tell with those insects. The multicolored Asian lady beetles that come into buildings seem to rise and fall with soybean aphid numbers, one of their primary prey species.
By some measures, the world reportedly experienced the hottest weather in recorded history this year. Is there any evidence yet what this means for insect populations?
We have not noticed a definite change in most insects due to warmer temperatures. However, bagworm, an insect pest typically found only south of Interstate 80 in Illinois, has been numerous in northern Illinois for several years. If a major change occurs in insect numbers in the future, it will probably be devastating to many other plant and animals species because insects are important in many ecosystems.
What steps can homeowners take now to minimize insect problems this fall?
Caulking cracks and crevices in the foundation of buildings helps keep insect invaders out. Removing fallen leaves and organic mulch from along outside foundation walls removes cover and food for many invaders, reducing the number that come indoors.