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The Extension Service is here to serve the residents of Columbia County, providing knowledge from universities nationwide. We provide research-based information to families, youths, schools, agricultural producers, home gardeners, foresters and governments.
Our office offers a variety of programs, which include 4-H Youth Development, Home Gardening, Agriculture and Small Farms, Family and Community Health, Forestry & Natural Resources and Master Gardeners.
We publish three newsletters from our office:
- Country Living (gardening and farming topics),
- Tall Timber Topics (forestry/wood lots), and
- Columbia Columns (for 4-H members and leaders).
If you would like to receive these newsletters by email or mail, please give the office a call.
Box Elder Bugs
Box Elder Bugs cause concern in the autumn (or in the spring when it’s time to leave the cavities in a home) when they gather in considerable numbers on the warm outside walls of homes and sometimes find their way into houses looking for a suitable place to over winter. They also seek shelter in such places as under the rough bark of trees or in tree hollows.
When they gain entry to buildings through cracks or other openings they remain in wall cavities and will occasionally emerge inside the home in the spring. They will not breed indoors, so there is no danger of starting an “infestation.”
They cause no structural damage whatsoever but they can “spot” interior furnishings with their droppings. They can’t bite, they don’t eat anything on the inside of your house, including house plants, and they won’t harm you, your family or your pets.
Box Elder bugs are elongate – oval insects about ½ inch long and 1/3 as wide. They are dark brown in color with several narrow reddish lines on the thorax and on the basal half of the forewings. They have rather long antennae and legs. The young nymphs are red and gray. The population of bugs may number into the thousands.
In the west, this bug should more properly be called the maple bug since that is its usual host and box elder is seldom seen. Eggs are laid on maple trees in the spring. The nymphs feed on foliage or developing seeds, using their piercing-sucking mouth parts. At The Dalles, the adults have caused damage to ripening peaches by their feeding. The bugs cause little damage to trees.
Insecticides rarely offer adequate control since modern insecticides are not very persistent, and a great percentage of the bugs are not contacted by sprays. It has been reported that sprays containing insecticidal soaps have been “surprisingly” effective. You can make your own - 5 Tablespoons of liquid dish soap to a gallon of water. Frequent applications on warm days when the bugs are active are recommended. This will reduce the populations but some will still enter the wall cavities if you don’t seal all the cracks. Tight screening of windows and other possible access points will reduce movement of box elder bugs into dwellings.
Inside the home, a good way to eliminate them is to vacuum the bugs up with a long hose attachment (to avoid staining fabric). If you squash them they may stain the walls or fabric. Remember they are harmless to humans and homes.
Hours of Operation
8 a.m. to 5 p.m.
Closed Fridays from Noon to 1 p.m.
OSU Columbia County Extension
505 N. Columbia River Hwy
St. Helens, OR 97051
For information on public transportation, visit the Columbia County Rider website.
We offer classes, workshops, opportunities for youth and adult volunteer activities:
Nutrition education events
Home Garden educational events