Brown Marmorated Stink Bug (BMSB; Halyomorpha halys) is an invasive insect pest which was first detected in Wisconsin in 2010. It is likely to become more and more evident in coming years, not only as a nuisance when adults aggregate and overwinter in our houses, but also as an economically-important agricultural pest. BMSB can be identified based on the white spots on their abdomen, white bands on their antennae, smooth shoulder, and brown-grey underside. However, many native stink bugs look similar to BMSB, which can make identification difficult.

BMSB was first detected in Wisconsin in 2010, and by 2015 was found in 11 counties. At present, BMSB is primarily regarded as a mild nuisance in Wisconsin, due to their tendency to aggregate and overwinter in homes. Trends in other states suggest that BMSB detection begins in urban areas, with populations slowly building up until, after about five years, bugs begin to appear as agricultural pests in the summer. Accordingly, it is likely that BMSB will soon move into agricultural crops, and will cause crop damage in Wisconsin over the next few summers. In fact, Michigan, which also first reported sightings in 2010, reported
BMSB as an “agricultural nuisance” in 2015. For these reasons, it is important to increase our monitoring of BMSB and learn management practices for how to control BMSB in Wisconsin crops.

The Brown Marmorated Stink Bug is highly polyphagous, with the potential to feed on many crops, including fruits, vegetables, and ornamentals. In particular, it has been shown to cause high levels of damage in apples, tomatoes, and sweet corn, and shows particular preference for trees with reproductive structures. For this reason, apple is especially likely to show BMSB damage in the coming years. Reports from the eastern states have shown on average 25% of apples in infected blocks show BMSB damage, amounting to an estimated $37 million profit decrease due to apple crop loss in the mid-Atlantic region in 2010. BMSB feeds by piercing the fruit and sucking juices, which can directly damage apples, causing a disfigurement commonly called “cat-facing”. In addition, damage from these bugs open the fruit up to secondary infections and necrosis, which cause the fruit to be unmarketable.

This pest presents a real risk to Wisconsin’s apple growers, and we will be working to reduce the risk of damage through a combination of monitoring, research, and education. In collaboration with Krista Hamilton from DATCP, Peter Werts at IPM Institute, and an outstanding group of grower collaborators (please see the box at the end of this article if you would be interested in joining our team!), we will be working to determine where in the state BMSB provides the greatest threat to apple production, when in the season they first appear in apple orchards, and to show the yearly phenology of this pest. With the help of a student intern hired through the Guédot Lab, we provide updates here through the summer, offering a real-time early warning system to let you know which farms are likely to be at risk, when BMSB is first present in orchards, and when control measures should take place.

Future work across the United States is looking at management practices for BMSB, in order to provide growers with a variety of IPM techniques. Some management tactics currently being assessed for BMSB include the use of physical barriers, such as row covers, repellents, biological control agents, and biopesticides, along with more traditional chemical controls. Along with updates regarding Wisconsin-specific BMSB distribution and phenology, we will also keep you informed of the most up-to-date management recommendations.

So, what does all of this mean for you? If you are growing apples or other susceptible fruit crops in Wisconsin, you will want to watch for our updates this summer in order to learn about the distribution, abundance, and phenology of this new pest. Additionally, we are looking for grower collaborators for this summer, so please see the box below if you would like more information about how to collaborate on this project!

This article was posted in Insects, WFN, Vol. 1-4 and tagged Brown Marmorated Stink Bug, Christelle Guédot, insects, Janet van Zoeren.