Damage

At this time (2020’s), for homeowners in northern Illinois, brown marmorated stink bug (BMSB) is mostly a nuisance pest, coming into homes in the fall and spending the winter.

They do not reproduce or feed indoors. Anyone who has them in their area may find them in fruit and vegetable gardens outside during the summer, as well as on some ornamental trees and shrubs.

These insects feed by sucking out sap from fruits and seed pods, damaging them, and making them unusable. This damage may also occur on stems and leaves.

For commercial growers, BMSB can be a serious pest, reducing the quality of crops so that they cannot be sold.

Life Cycle

Brown marmorated stink bugs (BMSB) spend the winter as adults in homes and other protected sites. They may be easily spotted in the home in late autumn as they enter through cracks and crevices. Once in the home, they hide in attics and other out-of-the-way places. While in the house, this insect does not feed or reproduce. BMSB does not bite and does not carry disease.

As outside temperatures begin to warm in spring, the overwintering adults emerge from hiding and try to find their way outside. Once outside, the adults will mate and begin laying eggs. Eggs can be laid from May through August. Eggs are light green in color and laid in a cluster on the undersides of leaves. The young nymphs that hatch out are reddish-orange and black. They will molt five times as they mature into adults. Nymphs will vary in appearance from molt to molt. Both nymphs and adults can feed on plants, so they can be a season-long pest.

The adult is about 1/2 inch long. Like many stink bugs, brown marmorated stink bug is a flat insect with a shield-shaped body. There are some markings that will separate this stink bug from others. The antennae are marked by light and dark alternating bands. The legs are also banded, but the bands are not as distinct as those on the antennae. The edges of the abdomen have very distinct dark and light bands, but this feature can be seen on other species of stink bugs as well. The insect’s “shoulders” are somewhat rounded, while other stink bugs have sharply pointed “shoulders”. The overall appearance of the body is a marbled color, with a row of creamy dots behind the head and on the edge of the triangle on the back of the insect (the scutellum).

Management

Cultural Management

To prevent brown marmorated stink bugs (BMSB) from entering the home, caulk cracks and crevices around doors, windows, air conditioners, and any other access points. Individual insects that enter the home can be removed by hand and discarded outside or into a bucket of soapy water. Handle the insect carefully, as it will smell when crushed. Groups of BMSB can be swept up with a hand-held vacuum and dumped into a bucket of soapy water.

If the insect becomes a problem in gardens, there are stink bug traps available for sale that can be used to reduce populations outside.

Biological Management

There is on-going research into the use of a parasitic wasp for management.

Chemical Management

Insecticides may be used for treatment of outside walls, soffits, and gables where the insect may be found in groups. This will manage populations, but will not give complete control. Any chemical management used should be coupled with cultural management practices.

The pesticide information presented in this publication is current with federal and state regulations. The user is responsible for determining that the intended use is consistent with the label of the product being used. The information given here is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement made by The Morton Arboretum.

For more information, contact The Morton Arboretum Plant Clinic (630-719-2424 or plantclinic@mortonarb.org).