Also elongate and worm-like, centipedes are known as hundred-legged worms and bear some resemblance to millipedes. They are different in that they have flattened bodies, a pair of long, slender antennae, a pair of claws just behind the head, and at least 15 pairs of legs, with only one pair on most body segments. They also move more rapidly than millipedes.
Egg -- White, creamy yellow, or brown, millipede eggs are smooth, spherical, and about 0.4 mm in diameter. They adhere in clusters due to the presence of a sticky secretion. Centipede eggs are similar.
Larva -- Smaller than adults, newly hatched millipede larvae have only three pairs of legs. Additional legs appear after each molt.
Hosts -- Moist, decaying organic matter is the primary food of millipedes. Centipedes, on the other hand, prey on insects and spiders.
Damage -- These arthropods are more of a nuisance than a threat. Millipedes occasionally feed on vegetation. Some species also exude a venom that blisters the skin and others emit an offensive odor. They do no significant damage to turf but are annoying when they leave their natural habitat and invade nearby buildings. Though some centipedes inflict a painful bite, the species most likely to enter houses does not.
Life History -- The life histories of these pests are not well-documented. The following information pertains primarily to millipedes, since these pests are more commonly encountered. In spring and again in fall, eggs are laid in clusters of 20 to 100 in the soil. Some females deposit as many as 300 eggs. Larvae emerge 9 days to 3 weeks later. Feeding on decaying vegetable matter, larvae grow slowly, developing through about 7 instars in 21 to 25 weeks. Adults are relatively long-lived. Millipedes overwinter in the soil or in other moist, secluded places.
If a general clean-up does not eliminate problems with these pests, pesticides may be used. Millipedes are controlled by spraying a 5-m band around the foundations of club houses or shelters. Chemical control of centipedes occurs only indoors. For recommended insecticide and rates, consult state agricultural extension service recommendations.