Stink bug or shield marmorated insect landed on a white blossom of spray carnation

Although there are plenty of species of stink bugs already causing problems on Kansas crops and plants, brown marmorated ones are especially atrocious. Besides their propensity to feed on just about any kind of plant and cause major economic crop damage, brown marmorated stink bugs are pests to homeowners when they congregate and enter houses in the fall.

Brown marmorated stink bugs (BMSB), or Halyomorpha halys, are about 1/2 to 2/3 inch long and shaped like a shield. The back of this species of stink bug is mottled brown and white as the name implies, and they have alternating bands of brown and white on their antennae.

There are more than 200 species of stink bugs in North America, so if you think you find BMSB it should be submitted to experts for proper identification. Specimens suspected to be BMSB can be submitted to K-State Research and Extension-Douglas County, 2110 Harper St., Lawrence, or your home county Extension office. Insects will then be submitted to entomologists at Kansas State University for confirmation.

BMSB are already a major problem in the eastern United States and there were unverified reports of them in both Kansas and Missouri last summer. BMSB are native to Asia and were first confirmed in Pennsylvania in 1998.

The Pennsylvania Department of Agriculture reports BMSB causes 25 percent crop loss in apples and stone fruit orchards, and up to 60 percent crop loss in fields and home vegetable gardens. BMSB is considered a major pest of fruit trees, vegetables, soybeans and ornamental plants. They will even feed on young trees by sucking the sap out through the bark.

Damage to fruit and vegetable crops from BMSB is usually in the form of pitting and scarring on the fruit or plant. BMSB has piercing-sucking mouthparts that are inserted into plant material to allow the insect to feed. On sweet corn and field corn, BMSB feeds on the tassel as well as the ear and interferes with pollination. In some cases, damage does not appear until weeks after feeding occurs.

Stink bugs get their name from their ability to release a pungent odor when they feel threatened. I like to think of them as the skunks of the insect world, although their aroma is much weaker than that of a skunk.

In the fall, BMSB enter homes through cracks and crevices just like the multi-colored Asian Lady Beetle that has been problematic in our area in past years. BMSB do not damage homes or pose human safety concerns, but the insects (and their odor) are a nuisance.

In February 2011, a West Virginia homeowner reported vacuuming 12,348 of the bugs from his home over a 45-day period.

The United States Department of Agriculture is working on various control strategies. Some success has been achieved with use of Kaolin clay and pyrethrums in organic production. Few insecticides are labeled for control of BMSB and even fewer are effective. If control of BMSB is needed, contact your local Extension office for current control recommendations.

Jennifer Smith is the Horticulture Extension Agent for K-State Research and Extension in Douglas County. She can be reached at 843-7058.