Millipede

Millipede Identification

Fully matured adult millipedes range in size and length depending on the species and can range in length anywhere between just 1.5 inches to 4.5 inches long. They are almost worm-like in shape which means that they are not flattened like their cousin, the centipede. Instead, they are cylindrical and elongated in shape. There are a few species that are slightly flattened in shape. Most of their segments have about 2 pairs of legs each with the exception of the first three segments on their bodies which only have 1 pair or even no pairs of legs. They possess very short antennas that are 7 segments long. They undergo a simple metamorphosis, which means that they do not go through the larvae or pupate stage. Instead, they simply keep their shape and form and grow longer with more segments added onto the body. The first instars have no more than 7 segments that make up their body and only 3 pairs of legs. As they molt and develop, they will add more segments and grow more pairs of legs throughout the course of their life.

Millipede Habits

Millipedes must overwinter in protected areas during the cold seasons. Although they need to lay their eggs in areas of high moisture like inside soil cavities or within organic matters that are decaying, they are able to breed all year round. Their development takes a bit longer than some of the more common house pests. There are about 7 to 10 molts until they reach full maturity and it will take at least a complete year until they have matured enough to begin reproducing. For some species, it even takes as long as 5 years. As they molt, they will consume their molted skins to restore all the lost calcium. Once they reach full maturity, adult millipedes will continue to survive for several years. Millipedes are not able to survive without high moisture levels. They will typically be found in areas of high moisture content and in decaying matter. These areas are places like under piles of grass clippings, mulch, in leaf litter, and etc.

They are active during the night and sometimes, in the fall season, some species of millipedes will migrate in large numbers. Their behavior of migration can be the result of several different situations including heavy rains that have forced them out of their harborage site, dry spells, extremely high numbers in population, warm temperatures, and etc. Many times, when millipedes exhibit this migration behavior, they will move in groups of few hundred individual millipedes all the way up to several million millipedes. They feed on decaying matter and are scavengers. Usually, it will be decaying plant materials that they feed on; however, they are able to feed on dead insects and earthworms. Also, they are not able to survive indoors due to this feeding habit as well as the dry moisture levels inside buildings. Although they may enter a structure, most likely, they will not remain inside.

Millipedes have several defense tactics to protect themselves from predators. Like the pillbug and sowbug, millipedes are able to roll up and only expose their outer shell. Also, they are able to excrete materials, fluids, or odors through the sides of their bodies. In some species, the fluid contains an acid that is toxic to some small animals and arthropods. This acid may also have a negative effect on the skin of people and will leave behind skin blisters.

How to Get Rid of Millipedes

Although they are only considered an occasional invader, millipedes can continue to wander inside structures if their outdoor harboring sites are not eliminated. The most important part of millipede control is mechanical control and exclusion. Mechanical control will involve eliminating all areas that will encourage nesting. This will involve removing debris, leaf litter, grass clippings, accumulations of wood debris and rocks, stored firewood that is close to the ground, and etc. Also, keep areas that are vulnerable to moisture and humidity, like crawl spaces, basements, and attics, dry and well ventilated.

Exclusion involves both mechanical control and chemical control. Seal all cracks and crevices with caulking and inspect utility lines that can lead indoors. Apply appropriately labeled pesticides in the wet-able powder form or micro-encapsulated form to create a barrier around the perimeter of the structure. Because they are crawling insects, the band of insecticide that is made to create a barrier does not have to be very high. Spray insecticide that goes up at least 4 inches from the base of the structure and at least 4 inches out from the base of the structure. Also, insecticides can be applied on perimeter flower and/or ornamental plant beds, crawl spaces, and basements. Dust products can be applied in restricted areas like the crawl space and unfinished basements. Keep in mind that you cannot apply insecticides on vegetable gardens, around and on fruit trees, or around other plants that bear edible materials. Also, all pest control products provide a product label and material safety data sheets. These labels must be thoroughly reviewed before any pesticide is applied.