Brown Marmorated Stink Bug: A New Invasive Insect Pest

The brown marmorated stink bug (Halyomorpha halys) has been detected in some Midwestern states. This invasive stink bug is native to China, Japan, Korea and Taiwan, and was introduced into the US in 1996. It can cause devastating damage to many crops, including tree and small fruit, vegetables, row crops, vineyards, etc. For example, in 2010 severe crop injury was reported in Delaware, Maryland, New Jersey, Pennsylvania, Virginia and West Virginia.

Currently, it is found in 31 states including Iowa, Michigan and Wisconsin. Its presence in Illinois and Missouri is unknown. Its additional status as a nuisance pest makes the brown marmorated stink bug different than other plant-feeding stink bug species. The adults enter homes and other buildings in the autumn seeking sheltered sites to spend the winter. The adults fly to these overwintering sites in mid September, and the peak flight activity is from late September until early October. The bugs are harmless to humans and pets as they do not bite, but they can become a nuisance when they congregate in large numbers outside and inside buildings. In extreme cases, hundreds can invade a home. When disturbed, the bugs produce a characteristic pungent, acrid odor that many people find offensive.

The adult brown marmorated stink bug has the typical shield shape of other stink bugs.  They are approximately 15 mm (5/8 inch) long and 8 mm (3/8 inch) wide. The upper side of the body is mottled shades of brown and gray, and is covered with dense puncture marks, as shown in the image below.  The word marmorated refers to its marblelike coloration. The adults of the brown marmorated stink bug can be distinguished from other species of stink bugs by the alternating dark and light bands on the last two segments of the antennae. The edges of the abdomen also have alternating light and dark banding.

If you happen to see a brown marmorated stink bug in your area, please contact the Missouri Department of Agriculture by contacting Collin Wamsley, State Entomologist at (573) 751-5505 or Dr. Jaime Piñero. 

If you are able to capture a specimen, please place it in any type of container such as a plastic medicine bottle or a film canister and put this in a freezer for at least 24 hours before submitting the sample. Digital pictures will also be useful.

(By Dr. Jaime Piñero, LUCE Integrated Pest Management State Specialist.)