Armadillidium gestroi
A compact, attractively patterned Mediterranean pill bug — moderate care, satisfying to keep.
About this species
Armadillidium gestroi is a compact isopod native to Italy and the surrounding western Mediterranean, prized in the hobby for its attractive dorsal patterning — typically dark grey with lighter cream or yellow markings. It is a smaller Armadillidium species, but what it lacks in size it makes up for in visual appeal.
As an Armadillidium, A. gestroi can conglobate — rolling into a tight ball when disturbed. It is a terrestrial crustacean that breathes through gill-like pleopods. Its thick, mineralised exoskeleton demands reliable calcium supplementation.
Enclosure
A ventilated plastic tub with a 20x15 cm footprint suits a starter colony. Moderate ventilation — enough airflow to prevent stagnation without excessively drying the enclosure. Cork bark, dried leaves, and cuttlebone are essential. A small piece of limestone adds environmental enrichment.
Substrate
- 60% coco coir
- 20% organic topsoil
- 10% fine sand
- 10% crushed limestone or cuttlebone powder
Maintain a moisture gradient — one damp end, one drier end. A. gestroi appreciates moderate humidity, slightly higher than A. vulgare. Depth 5–8 cm, topped with dried hardwood leaves. Never use softwood (pine, cedar) — toxic to isopods.
Feeding
- Dried hardwood leaves (oak, beech) — staple diet
- Vegetables: courgette, carrot, sweet potato
- Cuttlefish bone — leave permanently in enclosure; critical for Armadillidium
- Weekly protein: dried shrimp or fish flakes
Remove uneaten fresh food within 48 hours to prevent mould.
Breeding
A. gestroi breeds at the typical Armadillidium pace — steady but not fast. Females brood eggs in a marsupium and produce modest clutches. Colony growth takes patience. Starting with 20 or more individuals gives the colony the genetic diversity and breeding pairs needed to establish reliably. Expect six to twelve months to build significant numbers.