HOUSE CENTIPEDES ON THE MOVE
By Arthur V. Evans
One of my favorite non insect arthropod species is a fleet-footed fellow no more that one and a half inches long and has racing stripes down its back. Surrounded by a blur of legs in full stride, the house centipede, Scutigera coleoptrata, looks more spider and less centipede as it motors up a wall, along a sidewalk, or across the kitchen floor.
House centipedes are probably native to the Mediterranean region and have been accidentally transported to many parts of the world. In Tasmania, they are known as the “domestic quickfoot.” These curious animals are well-established across much of the warmer regions of North America, but have managed to penetrate cooler, less hospitable regions in the north by adapting to life indoors.
Outside, house centipedes are at home in the cool, dark, moist recesses of rocks, trees, and leaf litter. They are equally well suited to living in the basements, bathrooms, and drains of our homes, offices, and laboratories. Individuals are sometimes encountered when they become trapped in tubs and sinks, or are attracted to flying insects drawn to porch lights at night.
Hardwired with a “need for speed” to capture agile prey and escape equally nimble predators, house centipedes possess an array of unique morphological features. The distinct, capsule-shaped head is equipped with a pair of large compound eyes, an exceptional feature among centipedes. Acute vision is probably a major asset when a house centipede must quickly identify a potential prey item while on the run.
The structure of the house centipede’s eyes is similar to those of insects and crustaceans. As a result, they have been the objects of study for scientists seeking to better understand the evolutionary relationships of house centipedes with insects and other arthropods.
House centipedes sprint at speeds of 420mm/second; a 5’8” human would have to run the same distance, relative to their height, at a speed of about 42 miles/hour. But it takes more than the long, slender legs of a sprinter to get these centipedes up to speed; it also requires plenty of oxygen. Their lung-like tracheal system is unique among centipedes and allows oxygen into the body quickly and efficiently to help power the numerous muscles that drive the legs.
Most of their 30 long, slender, banded legs are used not only for getting around and escaping predators, but also to help capture and secure prey. When attacked, the house centipede’s legs easily break off and continue wiggling for a short period, like a lizard’s tail, to distract predators. Fortunately, lost legs are completely regenerated after just one molt. Under ideal conditions, adult house centipedes shed their exoskeletons every 30-60 days for the rest of their lives, which may last up to three years.
Centipedes are the only group of animals that have their front legs modified into fangs that inject venom to subdue and kill prey. Although they usually feed on invertebrates, some larger species will also attack small lizards, snakes, birds, and rodents.
The venom of house centipedes is not particularly toxic, at least not to humans. They seldom bite. Descriptions of the bites of house centipedes range from “minor nuisance” to “severe pain.” However, serious effects from the bite are more likely to be the result of secondary infection than the bite itself.
Still, house centipedes have become one of those “bread-and-butter” species of the pest control industry. Company literature and web sites would have you believe that these curious and largely beneficial creatures are major household pests. As with many “pests,” the greatest harm involving house centipedes is the “bite” to your wallet caused by the unnecessary purchase of pesticides to control these needlessly maligned animals. The truth is that they do more good than harm because they prey on scores of unwanted house pests, especially small spiders, clothes moths, and cockroaches. And they do all this without charging a dime for their services.
© 2010, A.V. Evans