By: Wizzie Brown
Centipedes and millipedes are members of the subphylum Myriapoda, which means many legs. Other myriapods include symphylans and pauropods, both of which look like centipedes. Most of these creatures live in humid, moist environments and can commonly be found in soil, in leaf litter, or under rocks or wood.
Centipedes and millipedes do not transmit diseases to plants, animals, or humans. These arthropods are more of a nuisance than a destructive pest. In centipedes, the first pair of appendages are modified into claws that can inject poison. The injury from 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, worm like, segmented body.
Centipedes have flattened bodies that can be brown, gray, red, or greenish blue. They have one pair of legs per body segment. The first pair of legs have been modified 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 in Texas are relatively small, Scolopendra heros (Fig. 1), can reach over 9 inches when fully grown.
The millipede body is cylindrical instead of flattened. Each body segment has two pairs of legs. Millipedes in Texas are typically brownish but can vary from red to yellow to orange. Millipedes often curl into a spiral to protect themselves when they are disturbed or when they die (Fig. 2).
Biology and Habits
Centipedes live for 1 to 6 years. They prefer moist, protected habitats such as under bark, stones, leaves, or rotted logs. They spend the winter as adults and lay eggs during the warmer months. The eggs are usually laid in soil and covered by a sticky substance. A few species give birth to live young.
Centipedes are predaceous; many species feed on other arthropods, such as insects. The modified pair of legs, or claws, is directly under the head.
Most centipedes can attack only with their poison claws, causing a beelike sting. However, Scolopendra can harm people with the sharp claws of its many walking legs. Each walking leg is tipped with a sharp claw that can make tiny cuts on human skin. A poison produced from the attachment point of each leg may be dropped into the wounds, causing inflammation and irritation. It is best to never handle centipedes.
The house centipede, Scutigera coleoptrera, may be found in and around damp areas such as in closets or bathrooms or underneath the home. House centipedes search for insects at night. This species reaches about 1½ inches long and has 15 pairs of long, slender legs. The back legs capture prey by using a “lassoing” technique. Although house centipedes are beneficial, many people consider them a nuisance in the home.
Millipedes can live over 10 years. They lay eggs singly or in small groups in the soil. These arthropods prefer cool, moist environments such as mulch, leaf litter, 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. After handling millipedes, wash your hands with soap and water until the odor is completely gone. Millipedes feed primarily on decaying organic matter; some eat other animals. Many millipedes may move into a home after heavy rainfall or during drought. However, they tend to die quickly because of lack of moisture and food.
To prevent millipedes and centipedes from coming indoors, move hiding sites—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 the flower beds against the home are mulched, 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 the seals around doors and windows as well as pipe penetrations for any points of access. On structures with brick or stone facades, stuff the weep holes with copper mesh or steel wool. (Because steel wool will rust if it gets wet, do not use it on light-colored facades.) Make sure that crawl spaces or areas under the home are properly ventilated.
Perimeter sprays around a building’s foundation may help keep centipedes and millipedes from moving indoors. Look for products with such active ingredients as cyfluthrin, deltamethrin, permethrin, bifenthrin, cypermethrin, or carbaryl.
Inside, treat cracks, crevices, baseboards, and other hiding places. Plant-derived pesticide formulations contain active ingredients such as d-limonene (citrus extract), rosemary oil, clove oil, thyme oil, or sesame oil. Other products available include active ingredients such as lambda-cyhalothrin, cypermethrin, permethrin, or bifenthrin. Treat wall voids with boric acid or diatomaceous earth.
Insecticide label clearances are subject to change, and changes may have occurred since this publication was created. 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 the label instructions.
Jared Ripple, Molly Keck, and Janis Reed reviewed this manuscript. Photographs by Wizzie Brown.
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