Millipedes first appeared in the fossil record 400 million years ago and are some of the first animals to have lived on land. It is hypothesized that these ancient species are the largest animals without backbones to have walked on earth. Modern forms appear in the late Paleozoic. While North American millipedes are currently classified as diplopods, Linnaeus classified them as apterate insects, Lamarck said they were arachnids, and others have called them worms or crustaceans. They belong to a diverse group with more than 10,000 described species.
North American millipedes sense their environment using their antennae, which can taste food, smell odors, feel, measure temperature, find water, and sense pheromones. Their Tömösváry organs, found at the base of the antennae, specifically measure humidity and possibly act as chemoreceptors. In addition, they have eyes on either side of the head which detect light and movement. Potential mates communicate using pheromones and silk trails.
Communication Channels: visual ; tactile ; chemical
Other Communication Modes: pheromones ; vibrations
Perception Channels: visual ; tactile ; vibrations ; chemical
This species has no special conservation status.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Fertilized eggs are laid in a nest made of chewed up leaves and excrement that is made by the female. Although most millipedes lay hundreds of eggs at a time, the scientific literature indicates that each North American millipede nest typically contains only one egg. When they hatch, young have three pairs of legs and seven body segments. With each molt, they gain more body segments, legs, and other structures. North American millipedes molt many times throughout their lifetimes and size is directly related to age.
Development - Life Cycle: indeterminate growth
These millipedes produce a substance that irritates and discolors human skin. In addition, they can do significant economic damage to root crops and are a nuisance when they swarm into homes and cover railroad tracks and roadways.
Negative Impacts: crop pest; household pest
Millipedes are model organisms for studying arthropod physiology and segmentation. Their defensive secretions may also show promise as sources of new pharmaceuticals.
Positive Impacts: source of medicine or drug ; research and education
North American millipedes are important in their ecosystems as decomposers, stimulators of microbial activity, and are very important in the cycling of terrestrial calcium. While this species does not act as a predator or parasite itself, they do engage in mutualism with certain species of ants, providing sanitary services in return for protection from predators. This species is an intermediate host to parasitic worms such as Oligacanthorhynchus tortuosa (before its definitive host, Didelphis virginiana) and Macracanthorhynchus ingens (before its definitive hosts, which include dogs, foxes and raccoons), protists (Enterobryus elegans and Enterobryus euryuri), and nematodes (Rhigonema sp.). They are also commensals with some species of mites (Narceolaelaps americanus in particular)
Ecosystem Impact: biodegradation
Species Used as Host:
Mutualist Species:
Commensal/Parasitic Species:
Millipedes are detritivores and prefer decaying leaves, wood, and roots, especially if the decaying matter has bacteria and fungi, which may increase the availability of nutrients and palatability. They sometimes eat live vegetation but rarely animal tissue. Most are coprophages and eat their own feces, which allows them to digest nutrients that were not digested the first time. They use their mandibles to bite and crush food into small pieces. Salivary glands open in the foregut and secrete a lubricating solution. Microorganisms in the gut help to digest tougher material.
Plant Foods: leaves; roots and tubers; wood, bark, or stems; algae
Other Foods: fungus; detritus ; dung; microbes
Primary Diet: mycophage ; detritivore ; coprophage
North American millipedes, including several sub-species, are found in the United States in all states east of the Mississippi River and nine states to the west (Minnesota, Iowa, Missouri, Arkansas, Louisiana, Nebraska, Kansas, Oklahoma, and Texas) and Canada (Quebec and Ontario provinces). This distribution is likely to change, however, as recent analysis of the taxonomy and distribution records of this species indicates that it probably represents a complex of multiple species.
Biogeographic Regions: nearctic (Native )
These millipedes are terrestrial animals most often found in forests and agricultural areas in the soil-litter layer interface under rocks, boards, dead trees, and piles of moist dead leaves, and occasionally in moist animal corpses. They are also found in urban and suburban areas. Because their cuticles are permeable to water, they are restricted to habitats where humidity is high, otherwise they quickly become dehydrated. While different species of millipedes have been found from sea level up to snow lines of mountains, the elevation boundaries of this species are unknown.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest
Other Habitat Features: urban ; suburban ; agricultural
North American millipedes typically live for several years. The longest recorded lifespan in this species is 11 years.
Typical lifespan
Status: wild: 1 to 11 years.
Typical lifespan
Status: captivity: 1 to 11 years.
Although their common name, "millipede," implies that these animals have one thousand legs, the highest number of legs on record for an individual is 375 pairs; most millipedes have fewer than 50 pairs. North American millipedes have two pairs of legs attached to each body segment (except for a few segments at the anterior and posterior ends that have one pair). Centipedes, a closely related group of animals, can be distinguished from millipedes as they have only one pair of legs per body segment and venomous claws below their mouths. In general, bodies of millipedes are long and cylindrical, with many segments that are covered by a cuticle consisting of three layers. North American millipedes can reach up to 2.5 grams in weight and 10.2 centimeters in length. Individuals are mainly black, though the edges of their body segments show a range of colors including yellow, purple and pink. All millipedes have spiracles on their body segments, which are connected to their tracheal respiratory system and pairs of ozadenes (stink glands) connected to ozopores. These ozopores release a noxious substance, produced by the ozadenes, which contains large amounts of benzoquinones and may cause chemical burns. Unlike many millipedes, North American millipedes do not release hydrogen cyanide when threatened. Sub-species of North American millipede differ in the number and appearance of legs and body segments as well as color. Typically, males of this species have longer legs and antennae than females.
Average mass: 2.5 g.
Range length: 10.2 (high) cm.
Other Physical Features: ectothermic ; bilateral symmetry
Sexual Dimorphism: sexes shaped differently
Millipedes have a variety of defenses against predators. North American millipedes secrete a substance containing large amounts of benzoquinones that may cause dermal burns and discoloration. In addition to defensive secretions, millipedes will roll up in a tight ball to expose their hard exoskeleton as armor. In spite of these defenses, North American millipedes are prey items to many other animals, including ants, beetles, birds, centipedes, cockroaches, dogs, foxes, frogs, lizards, moles, opossums, raccoons, salamanders, scorpions, shrews, skunks, toads, and turtles.
Known Predators:
North American millipedes breed seasonally, beginning in the spring and early summer. Males spin a silken thread and emit pheromones in order to attract females. During millipede mating, males walk along females' backs in order to stimulate them. Females will raise their front segments, allowing males to pass a packet of stored sperm (spermatophore) to females. Some females mate only once, using stored sperm to fertilize all the eggs laid while others mate multiple times with other males. Males typically mate with several different females.
Mating System: polygynandrous (promiscuous)
North American millipedes' breeding season begins in the late spring/early summer and continues into autumn. Eggs hatch within a few weeks of being laid, although development times can shift with temperature changes. A female lays one egg in her prepared nest then wraps herself around the egg for brooding. Once the egg hatches there is no further parental involvement. Young millipedes take 1-2 years to reach maturity, with males usually reaching maturity first.
Breeding interval: North American millipedes may mate multiple times during their breeding season
Breeding season: Late spring through autumn
Range number of offspring: 1 (low) .
Range gestation period: 2 to 10 weeks.
Range age at sexual or reproductive maturity (female): 1 to 4 years.
Range age at sexual or reproductive maturity (male): 1 to 4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous ; sperm-storing ; delayed fertilization
After mating, females may delay fertilization and protect the unfertilized eggs within their bodies. Females protect fertilized eggs by curling their body around them.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Female)
