Scutigera coleoptrata (one of several species commonly known as the house centipede), is a typically yellowish-grey centipede with 15 pairs of legs. Originally endemic to the Mediterranean region, the species has spread to other parts of the world, where it usually lives in human homes. It is an insectivore; it kills and eats other arthropods such as insects and arachnids. Its common names include “silverfish” in parts of America (though this is technically incorrect), gejigeji in Japan, and “mustache bug” in many other cultures.
S. coleoptrata is 25 mm (1 in) to 50 mm (2 in) in length and has up to 15 pairs of remarkably long legs. These delicate legs are attached to a rigid body. This enables it to reach surprising speeds of up to 0.4 metres per second (1.3 ft/s) running across floors, up walls and along ceilings. Its body is yellowish-grey and has three dark-colored dorsal stripes running down its length; the legs also have dark stripes. Unlike most other centipedes, house centipedes and their close relatives have well-developed, faceted eyes. S. coleoptrata has developed automimicry in that its hind legs present the appearance of antennae. When at rest, it is not easy to tell its front from its back.
Reproduction and Development
House centipedes lay their eggs in spring. In a laboratory experiment of 24 house centipedes, an average of 63 and a maximum of 151 eggs were laid. As with many other arthropods, the larvae look like miniature versions of the adult, albeit with fewer legs. Young centipedes have four pairs of legs when they are hatched. They gain a new pair with the first molting, and two pairs with each of their four subsequent moltings. Adults with 15 pairs of legs retain that number through three more molting stages (sequence 4-5-7-11-13-15-15-15-15 pairs). They live anywhere from three to seven years, depending on the environment. They can start breeding in their third year. For mating the male and female circle around each other. They initiate contact with their antennae. The male deposits his sperm on the ground and the female then uses it to fertilize her eggs. Some report that the eggs are deposited in the ground and covered with plant matter. Scutigera coleoptrata was observed providing parental care. The female lies on her side cradling her clutch of eggs, and later the larvae. This behavior was reported to proceed for several weeks. The female applies an antifungal secretion by mouthing the eggs.
Behavior and Ecology
House centipedes feed on spiders, bedbugs, termites, cockroaches, silverfish, ants, and other household arthropods. They administer venom through modified legs. These are not part of their mandibles, so strictly speaking they sting rather than bite. They are mostly nocturnal hunters. Despite their developed eyes they seem to rely mostly on their antennae when hunting. Their antennae are sensitive to both smells and tactile information. They use both their mandibles and their legs for holding prey. This way they can deal with several small insects at the same time. To capture prey they either jump onto it or use their legs in a technique described as “lassoing”. Using their legs to beat prey has also been described. In a feeding study, S. coleoptrata showed the ability to distinguish between possible prey. They avoid dangerous insects. They also adapted their feeding pattern to the hazard the prey might pose to them. For wasps, they retreat after applying the venom to give it time to take effect. When the centipede is in danger of becoming prey itself, it can detach any legs that have become trapped.
Outdoors, house centipedes prefer to live in cool, damp places. Centipede respiratory systems do not provide any mechanism for shutting the spiracles. That is why they need an environment that protects them from dehydration and excessive cold. Most live outside, primarily under large rocks, piles of wood and especially in compost piles. Within the home, these centipedes are found in almost any part of the house. Most commonly, they are encountered in basements, bathrooms and lavatories, which tend to be humid, but they can also be found in drier places like offices, bedrooms and dining rooms. The greatest likelihood of encountering them is in spring, when they come out because the weather gets warmer, and in autumn/fall, when the cooling weather forces them to find shelter in human habitats.
The faceted eyes of Scutigera coleoptrata are sensitive to daylight as well as very sensitive to ultraviolet light. They were shown to be able to visually distinguish between different mutations of fruit flies. How this ability fits with its nocturnal lifestyle and underground natural habitat is still under study. They do not instantly change direction when light is suddenly shone at them, but retreat to a darker hiding spot. Some of the plates covering the body segments fused and became smaller during the evolution to S. coleoptrata’s current state. The resulting mismatch between body segments and dorsal plates (tergites) is the cause for this centipede’s rigid body.
Interactions with Humans
Unlike its shorter-legged but much larger tropical cousins, S. coleoptrata can live its entire life inside a building, usually the ground levels of homes. They are generally considered harmless to humans. Bites (stings) are not common, and the forcipules of most house centipedes are not strong enough to penetrate human skin. Stings are generally no worse than a bee’s sting, with its venom causing redness and mild to severe swelling.
Techniques for eliminating centipedes from homes include drying up the areas where they thrive, eliminating large indoor insect populations, sealing cracks in the walls, and seeking the assistance of an exterminator. Thank you Wikipedia.
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