Armadillidium gestroi 'Milky Way' Isopods for Sale

Somebody fed this species to a bird and wrote down what happened. In a 2025 experiment, several isopods were offered to great tits, and Armadillidium gestroi provoked more discomfort behaviour than anything else in the trial: beak-wiping, feather-flushing, drinking. It has the strongest chemical protection of the species tested, and that is not a claim any shop had a source for until last year.

The line

'Milky Way' is a UK line, isolated and developed by Jennifer Gosling, who then shared stock out into the hobby. Everything under this name in the country traces back to that work.

The speckling is pale and milky against a dark body. We will not tell you it is bright white, because the hobby has not settled that: one UK seller trades this exact morph as a neon yellow animal, and at least one European supplier lists a separate Milky Way Yellow. Both descriptions are in circulation for what may be the same line. Ours read pale, and colour in this genus shifts with age and with the individual anyway.

The species underneath

Armadillidium gestroi, described by Tua in 1900. It is endemic to about thirty kilometres of Ligurian coast in north-west Italy, between Ceriale and Bergeggi, living in coastal shrubland on Triassic limestone. That geology is the reason calcium matters so much here: the wild animal grows up on a rock made of it.

Size: around 20mm, occasionally a shade over. The published maximum for the species is 22mm and the 2025 paper gives 20mm, so treat anything above that with suspicion. Figures of 25mm and higher circulate in the trade and one of them was on this page until today.

The wild type is dark with rows of yellow spots, and the warning colouration is real and not decorative, as the bird trial shows. Worth adding that across the species tested in that work, how conspicuous an isopod looked did not predict how well defended it was, so the spots are not a scale you can read. Adult females tend to develop a paler grey skirt around the edge, which is our own observation and not anything published.

Keeping them

The mistake to avoid is watering it. Gestroi is one of the drier Armadillidium and it needs real airflow. Aim for 50 to 70 per cent with most of the substrate left dry and one damp corner to retreat to, and give it cross-ventilation rather than a sealed lid. Temperature 18 to 26°C, so an ordinary room, no heating.

Substrate at five to eight centimetres, hardwood leaf litter across the top, cork bark for cover. Limestone in the enclosure permanently, not as an afterthought, because this species gets through calcium faster than most of the genus. Feed the usual range with protein regularly.

It conglobates fully, it is hardy once established, and it makes an excellent display animal precisely because it is large and pale-marked against dark leaf litter. Not the fastest breeder in the genus, but steady.

Two other gestroi lines sit alongside this one, the pale White Zinger and the oversized Jumbo, and the wider genus lives under Armadillidium isopods.

Captive-bred here. Livestock posts Monday to Thursday, packed on a moss bed inside a ventilated cup with a corrugated outer around it, and arrives the following working day before one o'clock with Royal Mail. we add 20% over the count on every order, and live arrival is guaranteed.