This year I seem to have many more boxelder bug on my house. We live next to the Cooper Mt Nature Center so they could come from any of the trees in the park. Is there any way to prevent them from coming onto my house? I have used the dish soap and sprayed them and this year I am trying to vacuum them but even after a couple of hours I still have hundreds on my house. What can I do.
Washington County Oregon
In the fall box elder bugs start looking for a warm spot to spend the winter. They congregate on the warm south and west surfaces of your house (and any other structure) and look for cozy cracks and crevices. To prevent them coming into your house seal all cracks and crevices around doors, windows etc with silicone caulk. Make sure screens are tight, including the frames which can bend enough to let the bugs into your house on a warm sunny day. Vacuuming is a good way to remove them from the inside of your house, disposing of the bag or vacuum contents right afterward. To get rid of them on outside walls hose them off with water or use insecticidal soap or laundry soap diluted with water. Be careful around plants when using laundry soap solutions. The insects have to be sprayed directly to have any effect. This article has additional information on control, Box Elder Bugs http://extension.colostate.edu/topic-areas/insects/boxelder-bugs-5-522/.
The favorite food of box elder bugs is the seed pods of box elder trees or other maples. The only permanent solution is to get rid of the box elder or maple trees around you. An unfortunate side effect of living near a park is the annual congregation of box elder bugs in the fall, but having the park and the gorgeous fall color of maples is worth the temporary inconvenience.
The good news is that soon the weather will turn permanently cool and they will no longer be active, but until then they will continue to congregate on warm sunny days. They are nuisance bugs, but can stain light surfaces and have an unpleasant odor when crushed. This article has additional information and pictures, Box Elder Bugs http://npic.orst.edu/pest/boxelder.html.