Minnesota Centipedes and Millipedes

Myriapoda is the subphylum of arthropods that includes centipedes, millipedes, symphlids, pauropods, and arthropleurideans. There are almost 13,000 described and an estimated 72,000 undescribed species of myriapods. This includes both still living (extant) myriapods and those known only from the fossil record. All myriapods are characterized by the following:

• elongated body;
• numerous body segments;
• a hard external skeleton (exoskeleton) made of chitin;
• a single pair of antennae;
• a single pair of mandibles;
• simple eyes only, no compound eyes;
• nine or more pairs of legs; and

• terrestrial.

Millipedes (Diplopoda) have long, cylindrical or slightly flattened bodies with 20 to 100 body segments. The first four body segments each have a single pair of legs. The last segment bears the anus and has no legs. The remaining segments are fused together in pairs, and each fused segment has two pairs of legs. The antennae are short, elbowed, and usually have seven segments. Few millipedes are predatory and none are venomous. They do not bite.

Centipedes (Chilopoda) have long, flattened bodies with 15 to 173 body segments. The segments are not fused together. There is always an odd number of pairs of legs. The legs on the first segment are modified into a pair of jaw-like venom claws behind the head. The last two body segments have no legs. All other segments have a single pair of legs. The antennae are long, thread-like, and have fourteen or more segments. All centipedes are predators, and all are venomous. All can bite and some inflict painful bites.

Symphlids (Symphlya) are not common. The are similar to centipedes but have only 10 to 12 pairs of legs. They are white, eyeless, and small, 1 ⁄32″ to 5 ⁄16″ (1 to 8 mm) long. The antennae are not branched.

Pauropods (Pauropoda) are not common. The are similar to centipedes but have only 9 pairs of legs. They are white or brown, eyeless, and minute, 1 ⁄64″ to 1 ⁄16″ (0.5 to 2.0 mm) long. The antennae not branched.

Arthropleurideans (Arthropleuridea) are extinct and known only from fossil records.