*Extension Agent-IPM, The Texas A&M University System.
Centipedes and millipedes are members of the subphylum Myriapoda, which means “many legs”. Other myriapods include symphylans and pauropods, both which are similar in appearance to centipedes. The majority of these creatures live in humid, moist environments and can commonly be found in soil, leaf litter or under rocks or wood.
Centipedes and millipedes do not transmit diseases to plants, animals or man. These arthropods are more of a nuisance than a destructive pest. Centipedes do have the first pair of appendages modified into claws which can inject poison. The bite of larger species of centipedes may cause discomfort. Millipedes occasionally damage seedling plants by feeding on stems and leaves.
Both centipedes and millipedes have a head with one pair of antennae connected to a long segmented body.
Centipedes are wormlike with flattened bodies. Color can vary from brown to grey to red to greenish-blue. Centipedes have only one pair of legs per body segment. The first pair of legs have become modified over time to function as claws used to capture prey. The claws are connected to poison glands that can inject venom to subdue captured prey. Although most centipedes found in Texas are relatively small, a larger species, Scolopendra heros (Figure 1), can reach over nine inches when full grown.
Millipedes have two pair of legs per body segment. Their bodies are cylindrical instead of flattened like centipedes. Millipedes in Texas are typically brownish in color, but can vary from red to yellow to orange. Millipedes often curl into a spiral to protect themselves when disturbed (Figure 2)
Biology and Habits
Centipedes live from one to six years. Centipedes prefer moist, protected habitats such as under stones, rotted logs, leaves or bark. They spend the winter as adults and lay eggs during the warm months. Eggs are usually laid in soil and covered by a sticky substance. A few species give birth to living young.
Centipedes are predaceous with many species feeding on other arthropods, such as insects. Their modified pair of legs, or claws, is directly under the head, allowing prey to be injected with venom.
Most centipedes can only bite with their poison claws located directly under the head resulting in a bee-like sting; however, Scolopendra can harm a person with the sharp claws of its many walking legs. Each walking leg is tipped with a sharp claw capable of making tiny cuts in human skin. A poison produced from the attachment point of each leg may be dropped into the wounds resulting in an inflamed and irritated condition. The best rule of thumb is to never handle centipedes.
The house centipede (Figure 3), Scutigera coleoptrera, is often seen in and around homes where dampness occurs such as closets, bathrooms or areas underneath homes. House centipedes are nocturnal and search for insects at night. This species of centipede reaches about 1 ½ inches in length and has fifteen pairs of long, slender legs. The back legs are used to capture prey by using a “lassoing” technique. House centipedes are beneficial, but many people consider them a nuisance pest in the home.
Millipedes are able to live over ten years. They lay eggs in soil singly or in small groups. These animals prefer cool, moist environments such as leaf litter, mulch or compost piles.
Millipedes are not poisonous, but have glands that produce a smelly fluid that can be irritating, especially if rubbed in the eyes. If handling millipedes, hands should be washed with soap and water until the odor is completely gone.
Millipedes feed primarily on decaying organic matter, though some are carnivorous. Homeowners may experience large numbers of millipedes moving into their home after heavy rainfall or during periods of drought.
To prevent millipedes and centipedes from moving indoors, move objects providing harborage such as compost piles, firewood and stones away from the structure. Create a band of gravel, or similar material between the foundation of the home and any flower beds that touch the structure. If you have mulched flower beds against the home, occasionally turn the mulch to allow it to dry out. Seal any accessible areas that may allow centipedes and millipedes to move into the home. Check seals around doors and windows as well as pipe penetrations for any points of access. Make sure that crawl spaces or areas under the home are properly ventilated to allow for air flow through the area.
Perimeter sprays around a building’s foundation may help keep centipedes and millipedes from moving indoors. Look for products with such active ingredients as deltamethrin, permethrin, bifenthrin or cypermethrin.
Inside the home treat crack and crevice areas as wells as baseboards, and other hiding places. Products available include active ingredients such as lambda-cyhalothrin, cypermethrin, permethrin or bifenthrin. Wall voids may be treated with boric acid or diatomaceous earth. There are also plant-derived pesticide formulations with active ingredients such as d-limonene (citrus extract), rosemary oil, clove oil, thyme oil or sesame oil.
Insecticide label clearances are subject to change and changes may have occurred since this publication was printed. The pesticide user is always responsible for the effects of pesticides on plants or household goods as well as problems caused by drift from their property to other properties or plants. Always read and carefully follow label instructions.
This is a revision of a publication written by J.W. Stewart.
The author wishes to thank Nathan Riggs, Paul Nester and Janis Reed for review of this manuscript.
Photographs by Wizzie Brown and Peggy Lawson
* *Extension Agent-IPM, The Texas A&M University System.