For Release October 9, 2005

Millipedes are Mighty Bothersome

by Chuck Otte, Geary County Extension Agent

My original plan for this week's column went out the window when the calls started coming in early in the week about the little brown worms that were everywhere and coming into houses. Time to switch to column topic plan B!

The little brown worms are millipedes. There are several different millipede species in Kansas. There are three orders of millipedes in the state, but the one that we are most commonly going to deal with as an invading home pest is in the order Julida. Most of these are dark brown, about 1/16 inch in diameter, and one to one and a half inches long. Millipedes have two pairs of legs per body segment. Their less common relative, centipedes, have but one pair of legs per body segment. When disturbed, they often coil up in a protective posture.

Millipedes, and centipedes, are both distant cousins of lobsters, crayfish and shrimp. The common roly poly, more correctly called pillbugs and sowbugs, are related to millipedes and centipedes and are in the order crustacea along with lobsters, crayfish and shrimp. Millipedes obviously don't appear to have a lot of defense mechanisms but they do have glands that can secrete an unpleasant musky odor when disturbed.

The millipedes live on damp and decaying wood and organic matter. They will also feed on tender roots and green leaves of plants. Their feeding practices rarely cause a problem for plant growth in the yard or garden. It's when they start looking for overwintering sites and decide that it would be a good idea to get into your house for the winter that they become a problem. They won't really eat anything in the house, but the mere presence of a few hundred of these rascals is unsettling enough, not to mention the odor that they will create!

Millipede populations often explode in the fall when there is a lot of decaying organic matter for them to feed on. Late summer rains create a good environment for them to live and multiply! Dealing with them is like dealing with any other household invading insect.

First of all, seal the house up as tight as possible. Caulk any cracks in the foundation, make sure that doors seal tight and even make sure that windows are well sealed and screens intact as they can crawl right up the side of a house. Clean up leaves and other dead or dying vegetation from around, or near, the foundation of the house. It can also be useful to remove mulch and rocks if flower beds are next to the house as these all provide hiding places for the millipedes.

If your house is being inundated with thousands of millipedes, it may be helpful to treat the exterior foundation with an insecticide. Some products to consider using are permethrin, cyfluthrin, esenfenvalerate, carbaryl (Sevin), and propoxur (Baygon). You may have to read the label closely to find out the active ingredients. Spray up on the foundation and out five to ten feet away from the house. Be sure to thoroughly cover sidewalks, steps, porches and all entryways into the home. Read and follow the label directions for mixing and using.

For controlling those that get indoors, the easiest way may be with a vacuum cleaner. The outside treatment should do a good job of stopping them from getting inside the house, but if you feel the need for an interior treatment, use one of the premixed ready to use products for indoor pest control, treating the baseboard area, thresholds of exterior doors and in areas where you see the millipedes collecting. One treatment should last for several months. Then have patience as the problem will diminish as the weather continues to cool down.


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