The answer to 'when to treat for stink bug' is that the best time to treat for stink bugs is in the fall, before they enter your home for the winter. Stink bugs typically become active in the spring and then start looking for places to overwinter as the weather cools down in the fall. Treating your home's exterior in late summer or early fall can help prevent stink bugs from getting inside and becoming a nuisance pest throughout the winter months.
It's important to treat for stink bugs before they make their way into your home, as they can be difficult to get rid of once they've taken up residence. Applying a targeted insecticide around doors, windows, and other potential entry points can help keep stink bugs out. You may also want to seal any cracks or gaps in your home's exterior to deny them access.