Kingdom:   Animalia
Phylum:     Arthropoda
Subphylum:        Crustacea
Class:        Malacostraca
Subclass:   Eumalacostraca
Superorder:        Peracarida
Order:       Isopoda
Suborder:  Oniscoidea.
Common names: woodlice, Woodlouse

A woodlice is not classed as an insect,  it is an Arthropod which is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages (paired appendages).

Isopoda is an order (group) of crustaceans that includes woodlice, sea slaters and their relatives. Isopods live in the
sea, in fresh water, or on land, and most are small greyish or whitish animals with rigid, segmented exoskeletons (external skeletons). They have two pairs of antennae, seven pairs of jointed limbs on the thorax, and five pairs of branching appendages on the abdomen that are used in respiration. Females brood their young in a pouch under their thorax. Isopods have various feeding methods: some eat dead or decaying plant and animal matter, others are grazers or strain food particles from the water around them, a few are predators, and some are internal or external parasites, mostly of fishes. Aquatic species mostly live on the seabed or bottom of freshwater bodies of water, but some more derived taxa (advanced groups) can swim for a short distance. Terrestrial forms move around by crawling and tend to be found in cool, moist places. Some species are able to roll themselves into a ball to conserve moisture or as a defence mechanism. (Wikipedia).

Terrestrial Isopodas play an important role in soil ecosystems by feeding on dead and decaying organic matter. They mix the litter, disperse fungal spores, and produce numerous faecal pellets. These activities enhance the decomposition process and speed up the recycling of soil nutrients.

For more details on Isopoda visit Massey University Guide to NZ Soil Invertebrates at

There is about 3,500 species of terrestrial Isopoda have been described worldwide; many more species are probably still undiscovered. Below are a few that are found in New Zealand.
An isopod found in decaying wood.
Isopods Order Isopoda-003.JPG 

Woodlice (Armadillidium species)
Slater Te Henui New Plymouth.JPG 

Woodlice (Blue) Porcellio scaber
Porcellio scaber 2.jpg

Woodlice (Pink colour form) Porcellio Species
Slater Pink Porcellio Species-1.JPG

Thanks to Wikipedia for text and information: