Emerald Cockroach (Pseudoglomeris magnifica)

Most cockroaches are a brown flicker vanishing under something. The emerald is out in the open in daylight, working its way up a branch, looking like a piece of polished jade with legs. It is one of the most striking insects kept in the UK, and almost nothing about it behaves the way people expect a cockroach to behave.

Introduction

This is the Emerald Cockroach, sold here as Pseudoglomeris magnifica, though you will also see it listed as Corydidarum magnifica, since the two genus names have been shuffled back and forth over the years and both are still in circulation. It comes from Vietnam and southern China, where it lives on lichen-covered bark and branches in the tree canopy rather than down in the litter, and it is that arboreal habit which shapes how you house it. The genus name is worth a mention too: pseudo for false and glomeris for ball-like, because close relatives in this group roll themselves into a sphere and this one, despite the family resemblance, cannot.

Appearance

The colour is why people buy them, and photographs undersell it. Adults are a deep metallic green that shifts with the light, closer to beetle iridescence than anything you associate with a roach, on a broad, domed, almost armoured body reaching around 3 cm. Males and females look genuinely different: females stay wingless and keep a rounded, juvenile shape into adulthood, growing larger and heavier than the males, while males develop wings on maturing and will make short flights around the enclosure. Both are day-active, which is the rarest thing about them, since it means you actually watch this species live rather than catching glimpses at night.

Care

Build upwards. These are climbers that want height rather than floor space, so a tall enclosure furnished with cork bark, branches and standing wood suits them far better than a wide tub. Give the lid your full attention: every stage climbs smooth surfaces, males fly, and newly hatched nymphs are around 3 mm and will find any gap you leave, so a tight-fitting or sealed lid is not optional. On conditions they are refreshingly undemanding, sitting comfortably between about 18 and 26°C, which suits a normal heated UK room, with humidity in the middle to upper range. They drink droplets from leaves and glass rather than standing water, so a light daily misting is the simplest way to keep them hydrated. Underneath, 5 to 10 cm of leaf litter and rotting hardwood over organic topsoil gives them somewhere to burrow and something to graze. Our flake soil and botanicals sit in the accessories range, and seeding the substrate with springtails keeps mould down in a setup that is misted daily.

Diet

Fruit first. Unlike most detritivores this species leans sweet, taking apple, banana and soft fruit readily, with vegetables alongside and leaf litter and decaying wood always present in the background. A protein and micronutrient source rounds it out, and bee pollen is a particular favourite of theirs, with fish flake serving the same purpose. Clear away uneaten fruit within a day or so, since it sours quickly in a humid, warm enclosure.

Breeding and maternal care

This is the part that surprises people. Females do not simply produce young and move on: newly emerged nymphs climb underneath their mother and ride there, tucked up between her legs and against her abdomen, for their first stages of life. Females have been observed sheltering nymphs that are not their own, and males are tolerated rather than driven off, so a settled group behaves more like a small society than a tub of insects. Females live around eighteen months and males roughly a year, and the species breeds steadily rather than quickly, which is part of why it remains uncommon and sought-after.

Who is this for?

The keeper who wants a display animal rather than a cleanup crew. It is the natural choice for a bioactive, planted, tall enclosure where its colour and daytime activity are on show, and it is genuinely one of the best conversation pieces in the hobby, including with people who arrive certain they dislike cockroaches. It is less suited to anyone wanting an animal to handle, since they are quick and inclined to climb straight up an arm, or to a keeper who cannot guarantee a genuinely sealed lid. If you want a roach you can hold, the docile Madagascar Hissing Cockroach is the better fit, and for a species with an extraordinary backstory the Simandoa Cave Roach is worth reading about. The full range is in our cockroach collection.

These are captive-bred and travel under our live arrival guarantee, packed with cover and moss inside a double-walled box. Orders leave Monday to Thursday on Royal Mail next day before 1pm, keeping every animal clear of the weekend.