University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

New Beetle Pest Concerns

October 18, 2001

Over the past few seasons, new insect pests have made a presence in northern Illinois. These include the multicolored Asian lady beetle, Japanese beetle, and Asian longhorned beetle. Sometimes there is confusion among these insects, so here's an overview of each.

Beetles actively flying on warm sunny October days and congregating in and around homes are multicolored Asian lady beetles. These are related to the native lady beetles or ladybugs, but were introduced into the southeastern United States for control of aphids on pecan trees. They have spread rapidly to other parts of the country. They come in various colors and numbers of spots, although 19 is the most common number. Asian lady beetles become pests as they try to enter building looking for shelter for winter.

Japanese beetles have become more common in Illinois over the past few years. They are larger than lady beetles (about 1/2 inch long), metallic green to copper in color, and adults are active during July and August. Japanese beetles feed on many types of trees, shrubs, flowers, and other plants in the landscape. Adult beetles lay eggs in lawns, which develop into white grubs. If Japanese beetles are in your yard right now, they are grubs down in the soil that will emerge next July as adult beetles.

The third species to review is the Asian longhorned beetle. This is a larger (3/4 to 1 1/2 inches long) shiny black beetle with about 40 white spots, mostly on the abdomen section of its body. They also have very long antennae that are 1 1/2 to 2 times the length of the body. It is native to China and first appeared in Chicago in 1998, coming from wooden crating material. It attacked hardwood trees, in particular maples. Infestations have been specific locations within Cook and DuPage county. The Illinois Department of Agriculture is closely monitoring and managing this pest.


Click here for the full article index