The powder blue isopod is a small woodlouse that looks dusted with a bluish-white powder, like the on a grape, which is where its pet-trade name comes from. Originally from Europe, it has traveled with people to warm regions around the world, including the US.

Appearance

Appearance
About ½ in (12–13 mm) long. The body is purplish brown to dull gray under a powdery blue-gray bloom, with long whitish legs and pale bands on the antennae.

Look-alikes

Common rough woodlousePorcellio scaber

The rough woodlouse has a bumpy back and a smooth oval outline. The powder blue isopod has a smooth, powdery back and a body outline that steps in between the front and rear halves.

Why they get mixed upBoth are common around houses and neither can roll up.

Pill bugArmadillidium vulgare

Pill bugs roll into a tight ball when touched. The powder blue isopod can't roll up and runs away instead.

Where it lives

Typical habitats
  • Under stones and logs
  • Leaf litter
  • Compost and manure piles
Range
Native to Europe and now found worldwide, mostly in warmer regions, often near people. In the US it is an introduced species; it was already being reported from upstate New York in the 1950s.
Preferred conditions
Needs damp shelter. In Britain it is especially common in manure heaps, compost piles, and around stables and barns, and it also turns up under logs, stones, and leaf litter.

Behavior

Diet
Decaying plant material such as rotting leaves and wood.
Activity
Mostly active at night. It cannot roll into a ball; when disturbed, it runs quickly for cover.

Name and classification

About the name
May actually be a group of very closely related species; ten subspecies are currently recognized. It was formerly placed in the genus Metoponorthus.
Varieties and forms
Hobbyists have bred several color forms, including "Powder Orange" and "White Out." Orange individuals also turn up rarely in the wild.

Conservation

IUCN Red List
NENot EvaluatedNot yet assessed

Culture and stories

Culture and stories
  • Easy to keep and quick to breed, it is kept as a pet and raised as live food for other pets.

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Powder Blue Isopod (Porcellionides pruinosus) — identification, habitat & look-alikes | Moeyo