College of Agricultural, Human, and Natural Resource Sciences

Department of Entomology

Box Elder Bug

Insects &

Black Widow Spider
Blister Beetle
Box Elder Bug
Cat Face Spider
Cat Flea
Cereal Aphid
Cereal Leaf Beetle
Corn Earworm
Crab Lice
Cooley Spruce Gall Adelgid
False Wire Worm
European Mantis
Jumping Spider
Juniper Scale
Locust Borer
Minute Pirate Bug
Mosquito Diseases
Northern Scorpion
Rose Curculio
Russian Wheat Aphid
Snowball Aphid
Ten Lined June Beetle
Western Yellow Striped Army Worm
Wheat Stem Sawfly
Wire Worm
Wooley ash aphid
Yellow Jacket Wasp
Yellow Sac Spider


Over Wintering True Bug

Biology: Many Hemipterous true bugs over winter as adults in shelters. In the PNW Region several species of little grey bugs of the Genera Irbisia and Ahryssa, etc.feed on grass land plants during the spring and early summer and overwinter in and around human structures. Locally known as “sage bugs” or “grey bugs” they seek layered places such as shingles, newspapers, firewood, folded fabric, etc. They are social and like to be together. Individual grass bugs emerge on warm, sunny, winter days to seek water droplets or house plants to obtain moisture. They do not feed while hibernating, but live off of their body fat.

Another pesty species is the Box Elder Bug, (Lepticorus trivittatus (Say), which a colorful larger bug than grass bugs. Box Elder Bugs are especially attracted to white houses and exhibit shelter seeking behavior much like the grass bugs. Rarely do the Stink Bugs (Genus Euchistus spp.) overwinter in homes, but prefer structures similar to the others including tree bark, wood piles, piles of lumber, etc.

All of these overwinter adult true bugs annoy humans by their presence even though they do not bite nor spread disease. Most true bugs stink! And they buzz around on active days. They congregate in sunny locations and try to go back outside when ready to mate and lay eggs in the spring.

Management: Many home owners and farmers want to spray these bugs as they come to hibernate in the fall of the year. They are easy to kill with products labeled for use in dwellings. However their little smelly bodies are still there! Our WSU suggestion? Vacuum them up in your home! Change vacuum bags because they stink after being filled with bugs.

Department of Entomology, Washington State University, Pullman, WA, 99164-6382 USA, 509-335-5422, Contact Us
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