Common Pill Bug
The common pill bug (Armadillidium vulgare) is a terrestrial crustacean that rolls into a ball when disturbed. Despite its name and its home under rocks and logs, it is not an insect but a relative of crabs and shrimp.
The common pill bug (Armadillidium vulgare) is a terrestrial crustacean that rolls into a ball when disturbed. Despite its name and its home under rocks and logs, it is not an insect but a relative of crabs and shrimp.
🧬 Field Guide Specimen: Open Common Pill Bug in the CRV Science Field Guide to log the specimen, see its place among the Ecdysozoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
A Crustacean on Land: How Does It Breathe?
Pill bugs breathe with gill-like structures on the abdomen, so they need damp places. They carry their eggs in a fluid-filled pouch (the marsupium) on the underside, a way of bringing the pond ashore.
Rolling Up
The overlapping plates of the shell allow the animal to curl into a tight ball, protecting the soft underside. This conglobation also reduces water loss. The related sowbugs cannot roll fully.
A Bacterium That Changes Sex
In some populations, the bacterium Wolbachia turns genetic males into functional females, a classic example of an endosymbiont that manipulates its host's reproduction. See Wolbachia.
Common Pill Bug at a Glance
| Property | Value |
|---|---|
| Scientific name | Armadillidium vulgare |
| Kingdom | Animalia |
| Phylum | Arthropoda |
| Subphylum | Crustacea |
| Class | Malacostraca |
| Order | Isopoda |
| Family | Armadillidiidae |
| Field Guide group | Ecdysozoa: Mandibulata (Mandibulates) |
| Diagnostic feature (Field Guide) | Domed slate-grey exoskeletal tergite plates capable of complete conglobation into a protective sphere, pseudotracheae on abdominal pleopods for terrestrial air-breathing. |
| Order | Isopoda |
| Defense | Rolls into a ball |
See Also
- Wolbachia — sex-altering endosymbiont
- Giant Isopod — a deep-sea relative
- Tongue-eating Louse — a parasitic isopod