Narceus americanus

Geographic Range

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 nearctic
  • native native

Habitat

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 temperate
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Other Habitat Features
• urban urban
• suburban suburban
• agricultural agricultural

Physical Description

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.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes shaped differently

Development

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 indeterminate growth

Reproduction

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) 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.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous
• sperm-storing sperm-storing
• delayed fertilization 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

Lifespan/Longevity

North American millipedes typically live for several years. The longest recorded lifespan in this species is 11 years.

Behavior

These millipedes are solitary and nocturnal. They hibernate during the cold, winter months and are most active at night. To avoid desiccation, North American millipedes initiate molting in moist places to reabsorb water through their cuticles. Millipedes are motile, using their multiple pairs of legs to move. Each pair of legs moves simultaneously, and subsequent pairs move in a wave-like motion down the axis of the body. They are capable of walking forward, backward, and side to side, as well as burrowing into soil. These millipedes may curl up if threatened, using their hard exoskeletons for protection, and also produce a noxious chemical to deter potential threats.

• Key Behaviors
• terricolous
• fossorial fossorial
• nocturnal nocturnal
• motile motile
• hibernation hibernation
• solitary solitary

Home Range

There is no published information regarding the home range of North American millipedes.

Communication and Perception

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 visual
• tactile tactile
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• vibrations vibrations

• Perception Channels
• visual visual
• tactile tactile
• vibrations vibrations
• chemical chemical

Food Habits

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.

• Primary Diet
• mycophage mycophage
• detritivore detritivore
• coprophage coprophage

• Plant Foods
• leaves
• roots and tubers
• wood, bark, or stems
• algae

• Other Foods
• fungus
• detritus detritus
• dung
• microbes

Predation

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.

Ecosystem Roles

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 biodegradation

Economic Importance for Humans: Positive

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 source of medicine or drug
• research and education

Economic Importance for Humans: Negative

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

Conservation Status

This species has no special conservation status.

Other Comments

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.

Additional Links

Encyclopedia of Life

Contributors

Kelli Millican (author), University of Michigan-Ann Arbor, Jeremy Wright (editor), University of Michigan-Ann Arbor.

References

Blower, J. 1985. Millipedes: Keys and Notes for the Identification of the Species . London: The Linnaean Society of London and the Estuarine and Brackish-Water Sciences Association.

Chamberlin, R., R. Hoffman. 1958. Checklist of the Millipeds of North America . Washington, D. C.: Smithsonian Institution.

Galloway, H. 2010. "North American Millipede, Narceus americanus" (On-line). Mountain Lake Biological Station, University of Virginia. Accessed January 22, 2013 at http://www.mlbs.virginia.edu/organism/northamericanmillipede .

Hopkin, S., H. Read. 1992. The Biology of Millipedes . Oxford: Oxford University Press.

IUCN, 2012. "The IUCN Redlist of Threatened Species" (On-line). Accessed January 26, 2013 at www.iucnredlist.org .

Kethley, J. 1978. Narceolaelaps N.G., (acari: laelapidae) with four new species parasitizing spiroboloid millipeds. International Journal of Acarology , 4/3: 195-210. Accessed January 23, 2013 at http://www.tandfonline.com/doi/abs/10.1080/01647957808683117#preview .

Misra, J., R. Lichtwardt. 2000. "An Overview of Trichomycete Systematics" (On-line). Accessed January 23, 2013 at http://www.nhm.ku.edu/~fungi/catalog.html#ENTEROBRYUS .

O'Neill, R. 1969. Adaptive Responses to Desiccation in the Millipede, Narceus americanus (Beauvois). American Midland Naturalist , Vol. 81 No. 2: 578-583. Accessed March 20, 2012 at http://dl2af5jf3e.search.serialssolutions.com.proxy.lib.umich.edu/?&url_ver=Z39.88-2004&url_ctx_fmt=info:ofi/fmt:kev:mtx:ctx&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=ADAPTIVE%20RESPONSES%20TO%20DESICCATION%20IN%20THE%20MILLIPEDE%20NARCEUS-AMERICANUS%20WATER%20STRESS&rft.aufirst=NEIL&rft.aulast=O&rft.date=1969&rft.epage=583&rft.genre=article&rft.issn=0003-0031&rft.issue=2&rft.jtitle=American%20Midland%20Naturalist&rft.pages=578-583&rft.spage=578&rft.volume=81&rfr_id=info:sid/www.isinet.com:WoK:BIOSIS .

O'Neill, R. 1968. Population Energetics of the Millipede, Narceus Americanus (Beauvois). Ecology , Vol. 49, No. 5: 803-809. Accessed February 06, 2012 at http://dl2af5jf3e.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info:sid/summon.serialssolutions.com&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Population+energetics+of+the+millipede%2C+%22Narceus+americanus%22+%28Beauvois%29&rft.jtitle=Ecology&rft.au=O%27NEILL%2C+ROBERT+V&rft.date=1968-01-01&rft.issn=0012-9658&rft.volume=49&rft.issue=5&rft.spage=803&rft.externalDBID=n%2Fa&rft.externalDocID=a08500380001 .

Ross, M. 2000. Millipedeology . Minneapolis: Carolrhoda Books, Inc..

Schimming, L. 2011. "Species Narceus americanus-annularis-complex - Narceus americanus/annularis complex" (On-line). BugGuide. Accessed January 22, 2013 at http://bugguide.net/node/view/15012 .

Shapiro, L. 2010. "Narceus americanus" (On-line). Encyclopedia of Life. Accessed February 06, 2012 at http://eol.org/pages/310313/overview .

Shelley, R., C. McAllister, M. Medrano. 2006. Distribution of the Milliped Genus Narceus Rafinesque, 1820 (Spirobolida: Spirobolidae): Occurrences in New England and West of the Mississippi River; a Summary of Peripheral Localities; and First Records from Connecticut, Delaware, Maine, and Minnesota. Western North American Naturalist , Vol. 66 Issue 3: 374-389. Accessed March 20, 2012 at http://dl2af5jf3e.search.serialssolutions.com.proxy.lib.umich.edu/?&url_ver=Z39.88-2004&url_ctx_fmt=info:ofi/fmt:kev:mtx:ctx&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Distribution%20of%20the%20milliped%20genus%20Narceus%20Rafinesque%2C%2018210%20%28Spirobolida%20%3A%20Spirobolidae%29%3A%20Occurrences%20in%20New%20England%20and%20west%20of%20the%20Mississippi%20River%3B%20A%20summary%20of%20peripheral%20localities%3B%20and%20first%20records%20from%20Connecticut%2C%20Delaware%2C%20Maine%2C%20and%20Minnesota&rft.aufirst=Rowland%20M%2E&rft.aulast=Shelley&rft.date=2006&rft.epage=389&rft.genre=article&rft.issn=1527-0904&rft.issue=3&rft.jtitle=Western%20North%20American%20Naturalist&rft.pages=374-389&rft.spage=374&rft.volume=66&rfr_id=info:sid/www.isinet.com:WoK:BIOSIS&rft.au=McAllister%2C%20Chris%20T%2E&rft.au=Medrano%2C%20Michael%20F%2E&rft_id=info:doi/10%2E3398%2F1527-0904%282006%2966%5B374%3ADOTMGN%5D2%2E0%2ECO%3B2 .

Sierwald, P., A. Reft. 2004. The Millipede Collections of the World. Fieldiana , 1, No. 103: 1-2.

Vattakaven, T. 2010. "Mating in Millipedes" (On-line). Nature Magnified. Accessed January 22, 2013 at http://www.naturemagnified.com/2010/06/mating-in-millipedes.html .

Williams, S., R. Hefner. 1928. The Millipedes and Centipedes of Ohio. Pp. 93-144 in Ohio Biological Survey , Vol. IV, No. 3, 18 Edition. Columbus, OH: The University Press.

2007. "Macracanthorhynchus ingens Homepage" (On-line). Penn Veterinary Medicine. Accessed January 23, 2013 at http://cal.vet.upenn.edu/projects/dxendopar/parasitepages/acanthocephalens/m_ingens.html .

2009. "Millipede" (On-line). New World Encyclopedia. Accessed January 22, 2013 at http://www.newworldencyclopedia.org/entry/Millipede .

2012. "North American Millipede" (On-line). Study of Northern Virginia Ecology. Accessed January 23, 2013 at http://www.fcps.edu/islandcreekes/ecology/north_american_millipede.htm .