Box Elder bugs and Lady Bugs

Asked March 18, 2013, 11:36 AM EDT

We have a small country church infested with Box Elder bugs and Lady Bugs. is there any type of traping system (eg. fly papers, Japanese Beetle traps) that we could install to trap and then remove the bugs. If no such trapping system exists, what fogging, spraying, etc., materials could we use to control the invasion? What are the negatives of the fogging/spraying systems?

Barry County Michigan

1 Response

The good news is that boxelder bugs and lady beetles are harmless pests that do not bite, eat wood or other building parts, do not carry disease, and do not breed inside buildings. They are a nuisance, though a temporary one. They both look for places to hibernate over winter. In the spring they then move around trying to find their way back outside. The lady beetle is actually a 'good bug' that helps control aphids on desirable plants during the growing season.

The pests already inside that you see wandering around you will want to remove. However, do not squash them, as both types of pest may stain carpets or other materials. Vacuum or sweep them up and deposit them outside. A light trap will attract the lady beetles in a dark building- traps can be purchased or you can build your own. The links below from OSU show how to build your own trap.

To prevent next fall's pests from coming into the building again, you should caulk around all openings 1/8th inch or larger. Check screens and doors, any areas where two different building materials come together, including the sill of the building, and around the opening where utility pipes and wires come in. Note that you should not close 'weep holes' - instead you can purchase special plugs that have little screens in them.

Insecticides that are formulated to use on the exterior of the building can help keep these pests out. Pyrethroids labeled for indoor use have some effect. But they will not have effects on the insects hidden from view. Indoor foggers are not recommended- they are not very effective on boxelder bugs or lady beetles. As always, read the label of each product you consider - be sure it is labeled to control the desired insect; and follow directions.

If you have boxelder trees (Acer negundo) very near the building you can reduce the number of boxelder bugs in your immediate area by removing the trees that produce seeds (these are the female trees, the males do not produce seed). However, boxelder bugs can fly a couple miles, so you will still have some, maybe many, in your area. If your boxelder tree is providing shade or a wind break, it may be worthwhile keeping.

I hope this information has helped. Please write back if you have more questions. Here are some links that discuss, in detail, control issues.

Boxelder bug-

Lady beetle home-made light trap-

Lady beetle control article