A Yellow and Black Flat Millipede crawling across pavement with wave-like action of its many legs. Apheloria virginiensis.

Wild Facts About The Yellow And Black Flat Millipede

ByChristine Wild Animals

Unmistakable Animals

  • The Yellow and Black Flat Millipede is unmistakable and very easy to identify in the wild.
  • Their common name describes the species very well. These invertebrates have:
    • Long, flattened bodies made up of 20 different segments, including the collum (head) and the telson (last segment).
    • Glossy black body segments, each with a backwards-curved, bright yellow point on each side,
    • Single, bright yellow spots on the center back of the collum and several segments at the end of the animal.
    • Two pairs of bright yellow, segmented legs on each body segment.
    • A pair of short, black, segmented antennae on their heads.
A Yellow and Black Flat Millipede with toe of a shoe for scale. Apheloria virginiensis.
Yellow and Black Flat Millipede Apheloria virginiensis Diplopod Photograph taken and design created by the author Copyright © 2025 Now I Wonder All rights reserved

Not Just a Fashion Statement

  • The bold color contrast between a Yellow and Black Flat Millipede’s glossy black body and its bright yellow spots and legs isn’t coincidental.
  • Yellow and Black Flat Millipedes are aposematically colored—the bold contrast between their black and bright yellow body colors visually warns predators that the millipedes are toxic to eat.
  • While some perfectly edible animals use aposematic coloration as a ruse to deter predators, Yellow and Black Flat Millipedes are the real deal.
    • These animals manufacture and store cyanide in their bodies.
    • Cyanide is extremely toxic—deadly in sufficient quantities—and can sicken or kill predators that try to eat Yellow and Black Flat Millipedes.
A Yellow and Black Flat Millipede with toe of a shoe for scale. Apheloria virginiensis.
Yellow and Black Flat Millipede Apheloria virginiensis Diplopod Photograph taken and design created by the author Copyright © 2025 Now I Wonder All rights reserved

A Strange Way To Grow Up

  • As adults, Yellow and Black Flat Millipedes have 20 body segments, either 30 or 31 pairs of legs (males and females respectively), and are about 1.6 inches (40 mm) long.
  • But these millipedes start out life with fewer segments and far fewer legs.
  • Yellow and Black Flat Millipedes hatch from eggs much smaller and shorter than they’ll eventually become.
    • As they develop, they undergo a series of molts, during which they shed their hard body covering and grow new body segments and additional legs.
    • Eventually, these millipedes reach adult size, stop molting, and remain stable until they die.
A Yellow and Black Flat Millipede crawling across leaf litter, seen from the side. Apheloria virginiensis.
Yellow and Black Flat Millipede Apheloria virginiensis Diplopod Photograph taken and design created by the author Copyright © 2025 Now I Wonder All rights reserved

Those Aren’t Legs

  • Male Yellow and Black Flat Millipedes have 30 pairs of legs, but females have 31 pairs. Why?
  • The eighth leg pair on males are actually gonopods, highly modified walking legs that transfer sperm to females during mating.
    • Immature millipedes of both sexes start out with all legs and both sexes add additional legs and body segments through molting.
    • But as male millipedes develop, leg pair 8 changes structure and turns into gonopods.
      • Even with recent advances in the study of DNA and genes, scientists rely on the structure of gonopods to identify millipede species.
  • Male Yellow and Black Millipedes store their sperm in structures within their third body ring and fill their gonopods with sperm prior to mating with females.
A Yellow and Black Flat Millipede chewing a dead leaf on the forest floor. Apheloria virginiensis.
Yellow and Black Flat Millipede Apheloria virginiensis Diplopod Photograph taken and design created by the author Copyright © 2025 Now I Wonder All rights reserved

Where to Find Yellow and Black Flat Millipedes

  • Yellow and Black Flat Millipedes live only in North Carolina and southern Virginia.
    • Their range extends from the Appalachian Mountains, east through the Piedmont and to the coastal plain in North Carolina.
  • These invertebrates are detritivores; they feed on decaying plant matter and live in forests and suburban areas with lots of leaf litter..
A Yellow and Black Flat Millipede chewing a dead leaf on the forest floor. Apheloria virginiensis.
Yellow and Black Flat Millipede Apheloria virginiensis Diplopod Photograph taken and design created by the author Copyright © 2025 Now I Wonder All rights reserved

Scientific Classification

Kingdom

Animalia (animals)

Phylum

Arthropoda (arthropods)

Class

Diplopoda (diplopods)

Order

Polydesmida (polydesmids)

Family

Xystodesmidae (flat-backed or keeled millipedes)

Genus

Apheloria

Species

A. virginiensis

Scientific Name

Apheloria virginiensis

  • This species used to be called Apheloria tigana but scientists have determined that A. tigana and A. viriginiensis are the same species.

Yellow and Black Flat Millipede Photo Gallery

Browse All Animals

A – Z By Common Name A – Z By Scientific Name

Browse By Type Of Animal

Amphibians Birds Insects Mammals Other Animals Reptiles Spiders

Browse By Animal Group

Alligators Beetles Butterflies And Moths Caterpillars Dragonflies And Damselflies Frogs And Toads Grasshoppers And Related Insects Landbirds Lizards Mammals Other Animals Raptors And Owls Salamanders Snakes Songbirds Spiders True Bugs Turtles Wasps And Related Insects Water Birds

Browse By Color

Black Black And White Blue Brown Gray Green Orange Red White Yellow

More animals are added regularly, so please visit again!

author avatar
Christine
Christine is the creator and author of NowIWonder.com, a website dedicated to the animals and plants that share our world, and the science that helps us understand them. Inspired by lifelong exploration and learning, Christine loves to share her knowledge with others who want to connect with wild faces and wild spaces.
See Full Bio