Millipede Facts, Identification, and Control in New York, New Jersey, and Connecticut
Scientific Order: Spirobolida
Most Common Species: North American Millipede
Scientific name: Narceus americanus
- Size: The common North American millipede may be anywhere between 1½ to four inches long. Millipede bodies are elongated, rounded, and cylindrical.
- Color: Brown, dark brown-red, or black. Legs may appear lighter in coloration than the main body. The North American millipede has distinctive red, yellow, or pink edges outlining each body segments.
Signs of Infestation
Millipedes commonly shelter under boxes or other storage material. You may find them after moving packaging material, especially in dark or quiet parts of your business. Millipedes require moisture to survive and will dry out and become "desiccated" if they don't get enough. Desiccated millipede bodies may flake or fall apart, leaving behind crusty remains.
Millipedes may secrete a foul-smelling liquid when threatened or crushed. This liquid may stain nearby fabrics such as carpeting. These stains will be small, vaguely circular, and yellow or brown in color.
Treatment and Prevention
Check for millipedes beneath storage materials in basements, crawl spaces, warehouses, and attics. Vacuum up any millipedes you encounter and dispose of the bag when finished. After removing millipedes, clear clutter to deprive millipedes of shelter. Manage waste diligently to control millipede's food sources.
If millipedes seem to live in your building for several weeks or more, then your building is probably too humid. Look for and fix causes of excess humidity. Patch up drafts, repair plumbing leaks, and make sure your ventilation and drainage work properly. Consider investing in dehumidifiers if the problem persists.
Behavior and Diet
Millipedes feed on decaying organic matter and are considered important natural recyclers. Millipedes live as close to reliable food sources as possible. They commonly infest rotting wood and actively seek out fungal growth. Millipedes thrive in dark, moist environments where they can access food. You may also burrow under soil to access rotting root systems.
Millipedes are very sensitive to temperature and humidity changes. They often migrate in large numbers during particularly wet or dry times. Millipedes move indoors to remain in dark, humid environments. Millipedes also move further from their usual places during spring and fall. During these seasons they may climb surfaces up to 6 feet off the ground.
Reproduction and Life Cycle
Millipedes undergo a three-stage developmental cycle consisting of "egg," "nymph," and "adult" stages. Millipedes start mating in early spring, but they can continue mating and laying eggs until temperatures begin cooling in the early fall.
Millipede nymphs look similar to adults but with fewer legs and body segments. Nymphs eat rotting material continuously in order to keep growing, and must shed their skin several times. Nymphs may not develop into fully-grown millipedes for up to two years. Millipedes may live for an additional 8 years after reaching adulthood.
- Despite the name, which is derived from the Latin “thousand legs”, no species of millipede actually has 1000 legs. Most of the millipede species in New York have fewer than 100 legs. Millipede legs are very small and located beneath each of the pest’s discrete body segments.
- The North American millipedes’ distinctive, colorful edges give the millipede a black-and-red “ringed” or banded appearance. Other species may not have the same banded appearance across their entire bodies, but most have some kind coloring to mark their edges or legs.
- Most millipedes have a hard, almost shell-like outer exoskeleton on the parts of their back that normally face upward.
- Cornell University Dept. of Entomology Insect Diagnostic Laboratory “Millipedes, Sowbugs and Pillbugs, and Centipedes” fact sheet
- Penn State Dept. of Entomology Cooperative Extension “Millipedes” Entomological Notes
- Study of Northern Virginia Ecology “North American Millipede” page