Issue 10, June 29, 2015


Millipedes are elongated, many-legged, hard-shelled, brownish, slow-moving insect relatives that feed on decaying plant material in moist situations. They have two pairs of legs per segment, totaling over one hundred legs per animal. Common millipede species are one to two inches long. In southern Illinois, there is a millipede that grows to six inches long. These large millipedes are commonly found under fallen logs in forested areas and are commonly kept as pets.


When very numerous, millipedes crawl out onto pavement, forming masses or rows of them on the march. On damp mornings, they crawl up the sides of buildings. As they die, they coil up. People commonly find them coiled up and dead in basements but they may survive in the high humidity of damp basements.

Homeowners that overwater heavily mulched ornamentals beds near foundations commonly find large numbers crawling on the sidewalk or patio. They tend to blame the lawn care applicator for the high numbers, but turf is usually not the cause unless it is overwatered.

Although they will feed on tender seedlings, millipedes are unlikely to feed heavily on older plants. Dead turf areas frequently contain very large numbers of them, causing them to be blamed at times for the damage when they have only moved in to feed of the decaying plants. Healthy turf typically contains numerous millipedes, so their migration into dieback areas can result in very high numbers very quickly.

Millipedes are apparently different enough in their physiology from insects that insecticide application results in very low, if any, mortality. Effective management relies on reducing dead organic matter and moisture. During rainy weather, patience and understanding is important. (Phil Nixon)

Phil Nixon

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