EPOW - Ecology Picture of the Week

Under the Wood

Lithobiid centipede (Lithobius sp.), Family Lithobiidae, Class Chilopoda
Eastern Oregon, USA

Explanation:  It's gardening time again, and if you check under many plank boards left on the ground, you may find this fleet-footed (many footed!), one-inch-long predator.

Don't be alarmed.  It is a lithobiid centipede, common inhabitants of gardens and yards.

A different species of centipede, hiding under a
down log in northern Arizona.

Centipedes can be the gardener's friend, as they are generalist predators and eat snails and slugs ... but also earthworms and soft insects.  The appendages on the first segment are modified into poison claws which are used to grasp their prey and inject venom, an interesting evolutionary convergence with venomous viper snakes.  

Centipedes generally have poor eyesight.  In fact, in some centipede families, their eyes are very simple and hardly used to locate their prey.  Centipedes are photophobic and run or dig away from light, which is why they are difficult to observe for long once uncovered in the daylight.

Centipedes have one pair of legs per segment, and the legs protrude from the sides, whereas millipedes generally have two legs per segment and their legs are set beneath the body.  Different centipede species can have 15 to 177 pairs of legs, and if a leg is lost, it is regenerated upon the next molt.  

Centipedes are very quick.  According to one source, a house centipede has been clocked at 42 centimeters per second ... which translates to, let's see, 1.5 km/hr or 0.9 mi/hr.*  For a multi-legged, nearly-blind invertebrate only an inch long, that is quick indeed!

*One mile per hour is also the maximum speed of the NASA Crawler that transports rockets, including the Space Shuttle, to their launch pads.  So a house centipede can keep pace with the Space Shuttle! (at least on the ground...)