Armadillidium nasatum 'White' Isopods

A body the colour of pale cream, and two dark eyes set into the front of it. That is what looks back at you out of a tub of Armadillidium nasatum 'White', and the eyes are the first clue to what the animal is. The shell has lost most of its pigment while the eye has kept it. Keepers expect an albino to lose pigment from both, but in a published breeding study of this species the albino lacked body pigment and kept normal eyes (Johnson 1984), so here dark eyes do not rule an albino out.

That distinction matters, because the hobby runs two near-identical names for two different animals. A 'White Out' is white or off-white all over, eyes included, and one American breeder calls it a simple recessive. This is not that one. If white eyes are what you are after, A. vulgare 'T-Albino' is the animal to look at in a species that rolls a closed ball, while the Porcellio scaber 'Whiteout' is another animal people sometimes arrive looking for by mistake, a flat, non-rolling woodlouse from another genus altogether. The White is sold as a reduced-pigment line, and how it arose has not been published.

Colour aside, this is Armadillidium nasatum Budde-Lund, 1885, the Nosey Pill-Woodlouse to British recorders. The species name, nasatum, means large-nosed, after a plate at the front of the head that points forward over the face. The British Myriapod and Isopod Group describes it as reminiscent of the peak of a base-ball cap. Losing pigment does not blur the feature, so a White seen in profile still shows the thing the species is named for. Adults finish at 12 to 16mm. The wild-type nasatum is the parent form here, and we run the Dalmatian and Orange lines out of the same species.

The ball never quite shuts

Disturb one and it rolls, but it stops short of a seal. A. nasatum manages partial enclosure only, and the antennae stay out through a small gap at the front where an A. vulgare would close flush. Nothing is wrong with the animal in your hand; it is how the species is built. Away from that, keepers do not agree on how much the animals show themselves: some say they roam the surface by day, others that they keep hidden and come out mainly at night.

Dry ground, not a wet box

Wild nasatum live in drier ground than most woodlice, sheltering under stones on sunny, sparsely vegetated sites. The figure people quote, roughly 45 to 80 per cent, is a tolerance band rather than a preference, so it should not be read as permission to keep them damp. Give the tub two ends instead. About a third of the floor area kept moist, the remainder left dry, and ventilation good enough that the dry side stays dry and does not simply end up less wet. Temperature is the easy part: 18 to 24°C is ideal, and an English home averages about 19°C over the heating season, so a heated room covers most of the year. If you want young through the winter, add a low-wattage heat mat or heat cable on a thermostat, fixed to the side of the tub and never underneath.

Underneath, 5 to 8cm of a nutritious base substrate. Bark on the surface for cover, dry hardwood leaf litter heaped over that as the standing food supply, and calcium left in permanently, cuttlefish bone or crushed shell, topped up as it goes down and never taken out. Vegetable scraps and a weekly pinch of dried protein finish the diet. This is UK captive-bred stock, hardy and forgiving, with sub-adults breeding before they reach full size; a small starter group grows into a working colony at a steady pace. Our guide to keeping Armadillidium goes further into the setup, and this one sits among the rest of the Armadillidium we keep. For this species on its own, including why a tub can run heavy with females, see how to keep Armadillidium nasatum.

Colonies travel in a ventilated deli tub with damp sphagnum for the journey, sat inside a double-walled box. We post Monday through to Thursday so that no parcel of ours should sit somewhere across a Saturday and Sunday, sending by Royal Mail on Tracked 24 or Next Day, depending on the service you select. Spares go in on top of whatever count is ordered, and live arrival is guaranteed.