We have had these bugs in our home for a few years, not many, but enough to be annoying.
We live in northern IL. Can we spray in the winter and have any effect on the population? We see none inside but they seem to be in the aluminum siding and that would be impossible to seal up to find every crack they are accessing to get in the house.
What is a good plan to control them now?
You could spray the CYPERMETHRIN listed in our BOXELDER BUG CONTROL ARTICLE. As long as they’re active and it’s warm enough outside, treating now would have an impact. But the best thing to do immediately would be to either dust with DELTAMETHRIN DUST up under the siding with a HAND DUSTER or use PT PHANTOM with it’s crack and crevice straw.
In the long run the dust would be the best since treatments would last 3-6 months. The Phantom would be easier to apply but expect to use it monthly since treatments won’t last as long. However, the Phantom is practically odorless so it could be used inside should the box elders start showing up in living spaces.
Ultimately you should really spray the outside of the home every fall to insure they don’t live under the siding during the winter. And again, a good dusting at this time would keep them away for sure.
Here are direct links to the information and products listed above:
Box Elder Bug Control: http://www.bugspray.com/articles98/boxelder.html
Deltamethrin Dust: http://www.bugspraycart.com/insecticide/dust/deltamethrin-dust