Originally published by Kelly Allsup on May 24, 2021.
They are crawling on my windows, walls, and houseplants newly rescued from the lower night temperatures of the fall and creeping me out. They could be hanging out on your dishes, doing a balancing act on your toothbrush, resting in your clothing or hair, or be a rather interesting ornament on your Christmas tree.
They are brown marmorated stink bugs, BMSB, and they are a new invader in Illinois homes as well as an invasive insect that may threaten our gardens. These insects are a nuisance because they do what stink bugs do best – stink, but only when threatened. The other issue is they move into your home without paying any rent.
This invasive insect was first identified in 1998 in Pennsylvania, is considered a stowaway from Asia, and causes most of northeastern states to dread the autumn invasion. BMSB’s have a large host range feeding on the landscape, native and agriculturally important produce. The BMSB has piercing mouthparts and is capable of damaging a multitude of crops from apples to pears to soybeans and landscape ornamentals. However, most reports so far come from urban areas during the fall, generally from homeowners and master gardeners detecting these invasive insects in their homes.
The BMSB body has the shield-shaped characteristic to stink bugs and it is as wide as it is long. The three most identifying characteristics are its black and white banding on the antennae, the alternating dark/light banding on the edge of the wings and the smooth shoulders.
They are capable of aggregating in manmade structures and recent USDA studies show they prefer large dead trees that are still standing in the forest-like oak or hickory on the East Coast. After overwintering in April, the adult lays 20-30 eggs with nymphs emerging shortly after. There can be multiple generations per year depending on seasonal temperatures.
Control stink bugs at home
- Use a vacuum to suck up adults or drop them in soapy water
- Take steps in early fall to caulk cracks and crevices around the house
- Prevent movement in from the outside by repairing windows and putting on door sweeps
- Perimeter spray of pyrethroids may be recommended
- It is not recommended to use sprays in the home because insecticide residues are relatively ineffective in providing control. The USDA currently classifies Illinois as being at low risk for the pest, as large numbers have not been recorded. The only good thing I can say is they will not reproduce in your home but wait until spring.
Learn more about Illinois invasive species.
Photo source: Kristie Graham, USDA ARS, Bugwood.org
ABOUT THE AUTHOR: Kelly Allsup is a Horticulture Educator for University of Illinois Extension serving Livingston, McLean and Woodford Counties. She meets the educational needs of her community, including local chapters of Master Gardener and Master Naturalist volunteers, through expertise in home horticulture and entomology. Her passion for ecologically-friendly gardening and all things plants makes her a dynamic speaker on topics that range from beneficial insects, growing vegetables and fruits, to urban trees.