Isopod

Armadillidium vulgare

Isopods are often known as "pillbugs", because they roll into a tight ball that looks like a pill. They are sometimes confused with "sowbugs" which look very similar. Sowbugs, however, have flatter bodies and cannot roll into a ball.

Isopods can grow up to half an inch. They are usually gray or brown or black, with an oval-shaped body. They have seven armor plates, called "pereonites," which protect them. They also have seven pairs of short legs.

Isopods have two pairs of antennae; one pair feels along the ground.

This animal is a crustacean, so its cousins are crabs, crayfish, and shrimp. Just like those creatures, Isopods have gills and need water to breathe. Since they live on land, and not in the water, Isopods must stay in moist places.

Isopods live under rocks, logs, leaves and other damp places. They can be found in forests, meadows, and basements. These animals are nocturnal, but will sometimes be found outside on damp, foggy days.

Isopods were introduced from Europe, but are well established in North America.

Female Isopods carry eggs in a pouch called a "marsupium." When the young Isopods hatch, they will stay in the pouch until they are old enough to be on their own.

Isopods eat fungi and decaying plant matter, as well as young plant growth, and sometimes dead animal matter.

Isopods live for about three to four years.

They have many predators, including: ants, spiders, shrews, toads, frogs, newts, lizards, small owls, foxes, centipedes, harvestmen, beetles, and even other isopods.

Isopods' ability to roll into a ball helps them defend themselves from some predators, especially ants and spiders which will give up.

Copyright 2002, William Leonard

Additional Media

Description
Type
Credit
Isopod Anatomy Diagram
Link to Printable Page
EnchantedLearning.com

Relationships in Nature:

PREY/FOOD
PREDATORS
SHELTER
OTHER

Turkey Tail

American Toad

Virginia Creeper

Crowded Parchment

Rabid Wolf Spider

Poison Ivy

Elegant Stinkhorn

Five-lined Skink

White Cushion Moss

Isopod

Least Shrew

Bracken Fern

Honey Mushroom

Wood Frog

Red Clover

Skunk Cabbage

Red Fox

Cinnamon Fern

Kentucky Bluegrass

Harvestman

Japanese Honeysuckle

Garden Centipede

Common Ragweed

Black Carpenter Ant

Black-eyed Susan

Wild Turkey

Skunk Cabbage

Eastern Newt

Running Cedar

Red-backed Salamander

Bird-foot Violet

Spring Peeper

Chicory

Eastern Bluebird

Kentucky Bluegrass

Eastern Mole

Wild Strawberry

Spotted Salamander

British Soldiers

Northern Bobwhite

Southern Leopard Frog

Ring-legged Earwig

Chigger

Relationship to Humans:

Some people consider Isopods to be pests, especially when found in garages or basements; however, Isopods rarely do harm. They may occasionally be a garden pest, but only when in great numbers. Isopods are of great value as a decomposer of dead plant matter.

SCIENTIFIC CLASSIFICATION

KINGDOM
Animal
PHYLUM
Arthropod
CLASS
Crustacean
ORDER
Isopoda
FAMILY
Oniscidae
GENUS
Armadillidium
SPECIES
Armadillidium vulgare

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