Giant Flower Cockroach (Eucorydia dasytoides)

For most of its life this is a drab little brown insect. Then a single final moult turns it into a metallic jewel. It is the payoff for patience. The Giant Flower Cockroach, Eucorydia dasytoides (you will also see it listed as E. aenea dasytoides under some treatments), is the largest Eucorydia in UK culture, and this slow reveal is the whole reason to keep it.

At around 15 to 20mm, it runs to roughly twice the size of the smaller Sapphire Flower Cockroach (E. yasumatsui), its close sister species, which makes the finished adult a far more commanding thing to look at. The nymphs give little away: small, brownish, easy to overlook among the leaf litter. Everything changes at that last moult, when adults emerge in iridescent metallic blue-green, often lit with orange or yellow accents across the wing covers, or tegmina, the colour shifting as the light catches it. This is a diurnal, day-active roach, so unlike most of its relatives you actually see it out and about in daylight, and adult males will take to the wing readily.

Keep it as a long-term display animal rather than a colony you expect to boom. It sits naturally alongside the other living jewels in the trade, the Emerald Cockroach and its own smaller sister, and it earns a place in any focused cockroach collection. One practical point before the colouring arrives: adults can climb smooth surfaces and the males fly, so an escape-proof lid is not optional once your nymphs start maturing.

Husbandry is undemanding once you get the airflow right. Hold it at 20 to 27°C, with a slight winter cool-down of a few degrees to echo its natural seasons. Aim for moderate humidity, somewhere in the 50 to 70% band, and understand that a drier box with strong airflow will always beat a wet, stuffy one. Ventilation is the single most important detail: give it high, generous airflow, because poor ventilation can collapse a colony faster than almost anything else. Lay down a deep layer of substrate so the animals can burrow, something like a rich flake soil, and dress it with cork bark and leaf litter for cover. Feeding is easy, as this is an unfussy omnivore: leaf litter and rotting wood form the base, topped up with a little fruit and veg and only an occasional trace of protein. A culture of springtails in the substrate keeps mould and waste in check across the long months ahead.

Breeding rewards a patient keeper. Females lay oothecae, small egg cases, tucking them into the substrate or fixing them to bark. From there the nymphs develop slowly, taking somewhere around seven to ten months to reach that final, transformative moult, and adults live only a few months once they mature. That short adult window is exactly why a mixed-age group kept steadily is the sensible approach, so there is always a cohort coming up behind the current adults and a new jewel arriving as the last one fades. If you are new to roaches, cut your teeth on the hardy Cuban Cockroach before taking this one on. The smaller Sapphire is no easier, despite its size, for the reasons set out in the Eucorydia care guide.

Every one we send is captive-bred and packed with care: a ventilated tub over a bed of damp sphagnum, cushioned inside a double-walled box. We dispatch Monday to Thursday by tracked next-day Royal Mail, aiming for delivery by 1pm, and every order carries our live-arrival guarantee along with a 20% overcount as standard.