Centipedes are related to millipedes and are also worm-like in form, but they differ in having flattened bodies and only one pair of legs on each body segment. They also possess a pair of poison claws or legs just behind the head which are used to paralyze their prey - usually insects or other small animals. Most centipedes are beneficial, but the large species found in the tropics, which may reach a length of up to 18 inches, can inflict painful bites.

Life Cycle

Millipede eggs are deposited in masses in the soil. Young millipedes have fewer segments than the adult, but they add segments at each molt of the outer shell, or exoskeleton. Molting occurs 7-10 times before maturity. Young millipedes mature the second year after hatching. Some species may live for several years. Similarly, centipedes molt several times, adding legs and body segments with each molt.

Damage

Millipedes feed on organic matter, including decayed plant material such as leaves and wood, and occasionally, living plant roots and rootlets, and developing fruit such as melons (especially cantaloupes) and cucumbers. Affected plants may wilt and die and melons may develop rots caused by bacteria or fungi which are introduced by millipede feeding. If millipedes are abundant in mulches and litter in landscape plantings around homes and other buildings, they often enter through cracks and crevices. Once inside, they usually die unless basements are very moist. Entry into structures is most common after heavy spring rains saturate the soil and drive millipedes to higher ground and in the fall, when they seek hibernation sites.

Centipedes can be found outdoors, often under stones, boards or in wood piles. They also live under leaf litter and other organic matter. Occasionally these outdoor species invade homes and buildings where they are a nuisance, but are not destructive.

Prevention and Control

To prevent millipede problems, simply reduce mulch thickness, reduce watering schedules or pull mulch away from plants and allow them to dry, reducing millipede feeding and reproduction. To prevent millipedes from entering homes, be sure that screens are tight, that moisture-holding debris in window wells is eliminated, and that mulches around ornamental plantings are at least 6-8 inches away from the foundation. Homeowners who need to control the house centipede should first get the pest identified to see if it is an invader from outdoors or an indoor species associated with an insect infestation. The continued presence of the house centipede, a long-legged, fast-moving species, may indicate a household insect problem, since these are their principal food. If centipedes are common indoors, look for insects such as cockroaches, attic flies, boxelder bugs, elm leaf beetles and others. Controlling these insects may be the key to eliminating the centipedes.

Removing mulch adjacent to the foundation or occasionally allowing it to dry out should also reduce centipede and millipede activity. Indoors, these pests may be controlled with natural or synthetic insecticide aerosols such as pyrethrins, available under many brand names. 
ECO PCO (natural)

To control millipedes and centipedes outside, establish a 3-5 foot wide barrier strip of a residual insecticide such as ECOPCO Dust or around the exterior home foundation to prevent them from entering. Prior to treatment, make foundation repairs and caulk all cracks and crevices. If your home is brick you may need Weep Hole Vents to prevent invasion.........

Courtesy of of Univ. Of Nebraska 
David L. Keith, Extension Entomologist 
Frederick P. Baxendale, Extension Entomologist

The named brand products mentioned in the control measures are not a recommendation of Nebraska University or
David L. Keith, Extension Entomologist or 
Frederick P. Baxendale, Extension Entomologist