|SCIENTIFIC NAME: Scolopendra heros (Girard)|
These fast moving and aggressive titans are among the largest of the many-legged centipedes and millipedes, the group collectively known as the Myriapoda. Centipedes are distinguished from millipedes by the presence of only one pair of legs per body segment, and their legs are attached to the sides of the body segments rather than near the ventral midline. They comprise the Class Chilopoda, which scientists divide into four orders. Giant centipedes are in the Order Scolopendromorpha, which is distinguished by having 21 or 23 pairs of legs and, usually, four small, individual ocelli on each side of the head. The closely related Geophilomorpha lack eyes. Most Scutigeromorpha (of which there is only one North American species) and Lithobiomorpha have eyes similar to the compound eyes of insects, each consisting of up to 200 optical units similar to ommatidia, and adults in these two orders have only 15 pairs of legs.
Life Cycle: Giant redheaded centipedes are not frequently observed or collected, but those that make themselves known attract a great deal of attention because of their size and fierce appearance. Specimens average about 6 ½” in length, and they may reach nearly 8” in some instances. They have been called “giant desert centipedes,” but this appears to be a misnomer because the centipedes are often collected in rocky woodland in Arkansas. The species is also known to occur at least in Arkansas, southern Missouri, Louisiana, Kansas, Oklahoma, Texas, New Mexico, Arizona, and northern Mexico. Scolopendra heros has many color variants, but Arkansas specimens have the so-called castaneiceps pattern in which the head and first two body segments are chestnut red, the trunk is black tinged with green, and the first 20 pairs of legs are yellow. The enlarged legs of the 21st pair at the posterior end of the centipede are black with yellow tips. This bright coloration is known as aposematic coloration or warning coloration and it is presumed to function in warding off potential predators by advertising the centipedes’ confrontational character and poisonous qualities while it goes about its daytime activities.
Habitat, Food Source(s), Damage: All centipedes are believed to be predators. Their diet is composed primarily of small arthropods, although some scolopendromorphs have been found feeding on toads, small snakes, and other vertebrates. Moths are a preferred diet for captive giant redheaded centipedes. The prey is captured and killed or stunned with the poison claws. Poison glands are located in the basal segments of the claws or fangs, sometimes called maxillipeds. Each gland drains its toxic contents through a small opening near the tip of the fang. In the mid 1920s, Dr. Baerg tested the effect of the venom by inducing a centipede to bite one of his little fingers, leaving the fangs inserted for about four seconds. The bite was followed by a sharp and strictly local pain, which began to subside noticeably after about 15 minutes. In about two hours the pain was only very slight, but there was a general swelling in the finger. Three hours after the bite, most symptoms had disappeared.
References and Resources: Jeffrey K. Barnes, University of Arkansas Arthropod Museum Notes, http://www.uark.edu/depts/entomolo/museum/sheros.html; Brook et al. 1982; Drees & Wicksten 1990; http://insects.tamu.edu.