QUESTION:

I am dealing with stink bugs in the second floor office of a home. The home has all new windows and seems to be recently remodeled. Any suggestions on where they may be entering?

ANSWER:

These insects, and essentially the Brown Marmorated Stinkbug these days, are small enough that a great many opportunities to get inside a structure exist, other than just gaps around windows. Normally this problem occurs in the fall, although it may be that you are now seeing the results of these bugs having been in this home all winter long, and now just getting active and looking for ways to exit the building. It could be that they were cozied away up in the attic or in the wall voids for the past 6 months without anyone knowing they were there, and now they have warmed up and are moving down through ceiling fixtures and vents and any other openings they might find, to become visible to the occupants. May be they moved down into wall voids and out through switch plates, but moving toward "light" would be a more normal habit, and ceiling lights could offer that little lighted area that draws them.

As far as how they enter initially, it could be almost any gap more than about 1/8 inch wide. Susceptible places on a structure run from ground level up to the roof and the chimney, so flashing on the roof, shingles and other roofing covers offer gaps, chimneys offer gaps, there are notoriously gaps under the eaves around attic vents and soffits, gaps where plumbing and other services enter the home, gaps around crawl space vents or holes in the vent screens, under siding, etc. It can seem like a monumental task to address every possible entry point to plug them and prevent these bugs from entering, but if taken one "bite" at a time and done over a long period of the year, suddenly you find 90% or more of the entry points permanently sealed. Every gap or hole you manage to close presents one less opportunity for the stinkbugs, and coincidentally any other bugs that like to overwinter in homes, to enter. This includes ladybird beetles, cluster flies, other true bugs including a few kinds common in the western states, and even rodents and bats.

Why the emphasis on Exclusion? Well, this is the long term answer if we are really trying to use insecticides properly. We can definitely cut down the numbers of stinkbugs that get into a home by spraying the exterior walls in the fall and fogging or dusting the voids inside after they get in. But, this will then be an endless process that needs repeating annually, perhaps more than once each year, and what is more satisfying to the customer and is a more responsible IPM approach is to permanently exclude them so pesticides are no longer needed. It also relieves the customer of having to see the bugs in their home at all.

This kind of exclusion effort will take a tremendous cooperation from the customer. They may choose not to do this kind of exclusion themselves and actually pay YOU to do it for them, and if so you could make good income charging by the hour to seal off all those gaps. Option 2 is that they choose not to do it themselves and don't want to pay to have it done either, and instead just ask you to go ahead and "spray something" every year to knock down the problem the best you can. I think there still is that belief amongst the public that pesticides are magic potions that somehow make all bugs fall over dead instantly and with a little luck even disappear as they die. Good stewardship of the chemical tools we have available means using them only as needed, and addressing non-chemical pest management whenever possible.

So, grap the flashlight, some binocular, a ladder, and a written inspection form and diagram of the home, and wall by wall inspect to determine where all of these entry opportunities are. Then you can suggest how these can be closed permanently, a little at a time, so that the bugs no longer can get inside where they are a much bigger concern.

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