Stink bugs, galls and gardening reminders

By John Fulton

Send a link to a friend

[April 21, 2011]  The brown marmorated stink bug in Illinois -- According to Kelly Estes, University of Illinois entomologist, the brown marmorated stink bug, known as BMSB, has been making headlines in Illinois the past couple of weeks. After the first confirmation of this invasive insect was reported in the fall of 2010 in Cook County, additional reports have been received from Kane, McLean and Champaign counties in 2011.

Like many invasive species, BMSB has a long list of host plants, including many woody ornamental trees as well as several agricultural crops, including fruit trees, grapes, tomatoes, corn, soybeans and others. Also, like many other invasive insects, it is easily moved from location to location by humans. This happens, for example, with the insect hitchhiking on vehicles and during movement of shipping materials and plants.

In addition to feeding on plants, BMSB is also considered a nuisance pest to homeowners. Much like boxelder bugs or multicolored Asian lady beetles, these stink bugs congregate on houses in late fall and move indoors. Homeowners are likely to first spot new infestations as these insects will initially feed on common landscape ornamentals.

Unlike many insect pests that attack plants only during certain times of the growing season, the BMSB will feed on host plants all season long. This causes great concern in fruit crops, where the insects begin feeding early in the season and continue through harvest. Growers should monitor fruit for sunken areas where the insect has fed. Discolored and corky areas will be present under the skin of the fruit. In corn and soybean, BMSB feed on the developing pod or corn ear. The insects are able to feed through the husks and pods with their sucking mouthparts, causing shriveled kernels and beans, respectively. In tomatoes and peppers, feeding will also result in corky areas and discoloration, much like injury in fruit.


A group of problems showing up is galls. Galls are swelling of leaves, twigs or other plant parts. Most are caused by mites or wasps. They damage the plant parts and the plant responds with a gall. In the case of leaves, the swelling is actually leaf tissue. This is something I like to refer to as similar to you getting a mosquito bite. The damage comes in and a swelling occurs. There is no way to get rid of it without tearing a small hole in the leaf.

The maple leaf bladder gall will be easily spotted on silver maples in the area shortly, and oak leaves in the red oak group are also showing galls. Oak trees probably have more galls than any other group of trees. Several samples have also been brought in of the stem types of galls. Fortunately, the oak galls are usually not the type to kill tissue beyond them.

Galls aren't the most pleasant things to look at. That is the main thing -- they are unsightly.

There is no cure for galls, as they are caused by insects before you see the swellings. The timing would be impossible to try to prevent the insects.

Gardening reminders

  • We are on the early end of the time period for planting tender vegetables such as snap beans, sweet corn, New Zealand spinach and tomato plants. The dates are April 25 to May 10.

  • May 10 begins the time for planting warm-loving vegetables such as squash, melons, cucumbers and sweet potato slips. This is also a "more assured" date for planting annual flowers.

[By JOHN FULTON, University of Illinois Extension]

< Top Stories index

Back to top


News | Sports | Business | Rural Review | Teaching & Learning | Home and Family | Tourism | Obituaries

Community | Perspectives | Law & Courts | Leisure Time | Spiritual Life | Health & Fitness | Teen Scene
Calendar | Letters to the Editor