Stink Bugs and Window Weeps

This stink bug would appreciate a free pass into your home (or for that matter, your office). Learn how to keep it out.

After a few splendid years of low stink bug populations, we find ourselves in the midst of an epic invasion. In the past few weeks, I have captured dozens of brown marmorated stink bugs (aka BMSB), which fly from surrounding trees and perform a smack-landing onto my screen windows.

I do my best to capture the BMSB I see with a cup of soapy water. Simply place the cup under the bug and put your other hand over the bug. As a defensive mechanism, stink bugs will drop into the cup, requiring no physical contact on your part. Just toss them out the door or off your balcony. Or you could wrap it in a tissue and squish it; the tissue will keep stinky oils off your hands and out of the air. (As your final coup, you could drop the tissue in your compost bucket.) Both methods save a five-gallon flush down the toilet — really, you don’t ever have to flush stink bugs.

For the stink bugs I don’t catch, I try to keep them out of my house by making sure that my windows screens aren’t torn, there are no gaps around my windows and doors (they fit snugly into the frame), vents are screened or louvered, and window air conditioning units are removed before autumn — all key preventive tactics and core to good IPM. But I recently observed a new entry point on windows that I hadn’t considered before: the window weep hole.

Holes in screens are an invitation to stink bugs and other pests.
This window weep is missing its cover.

Weep holes are design features that allow water to escape from a structure, whether it’s a window, sliding door or a brick building. Weep holes must remain open for water to drain even as they exclude pests. For example, weep holes in brick can be covered with specifically designed screen materials or filled with pest exclusion products such as Xcluder Fill Fabric*. Newer windows have weep hole covers that function like one-way-doors: they open to drain water but are otherwise closed. Sometimes — as in the case of my windows — these break off, leaving an excellent entry point for pests such as BMSB. Once bugs enter the weep hole, they can climb up through gaps into the window track and into the space between the screen and the windowpane. When you open the window, well — you just gave them a free pass into your home.

Weep hole covers are available for purchase at a number of outlets, but you must buy the right cover to fit the dimensions of your window. Because of the variability in window weep hole sizes, pest professionals and maintenance personal who manage offices and apartment buildings might choose to use Xcluder Fill Fabric that can be cut to the proper size, providing both pest exclusion and water drainage.

*NOTE: Trade names used herein or products shown are for convenience only. No endorsement of products in intended, nor is criticism of unnamed products implied.

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