Madagascan hissing cockroach

Gromphadorhina portentosa is a wingless Madagascan cockroach that hisses by pushing air through breathing openings. Males usually have more prominent bumps behind the head. Other hissers and hybrids occur in trade, so appearance alone cannot certify a pure species line.

Plan a continuing colony rather than assuming two adults remain two. Females retain developing eggs internally and release young nymphs. Ask about species and breeding history and arrange contained surplus management. Warmer conditions can increase breeding; heat is not simply a way to improve viewing.

The proposed starter layout is 45 × 45 × 60 cm with stable climbing structures and several retreats. Expand or separate as numbers grow. Secure lids, doors and cables with nymph-safe ventilation. These insects climb glass, so smooth walls do not make containment reliable.

University colony guidance describes around 22–24°C, with more breeding at warmer conditions. Measure minima and maxima before adding heat. Older suggestions for heat rocks or unregulated mats are not adopted. Preserve cooler shaded choices and avoid drying every retreat.

Use a normal day-night rhythm with dark shelters. No mandatory UVB or numeric UVI target is established in the institutional guidance. A bright basking lamp is not a default requirement.

Provide moist refuges with airflow and drier choices, avoiding saturated substrate and moulding food. Use hydration methods safe for the smallest nymphs. Deep open bowls can drown them, so review depth and exits rather than borrowing an adult reptile bowl unchanged.

Offer a suitable balanced dry roach or insect feed with modest fresh vegetable and fruit variety. Keep dry food from becoming wet and mouldy and remove fermenting leftovers. One sweet fruit is not a balanced replacement, and small nymphs still need safe hydration.

Expect climbing, social interactions and male territorial behaviour. Provide several shelters and check for persistent exclusion or injury. Use gentle contained transfers without pulling gripping feet free. Hissing is communication or defence, not a reason to keep provoking the colony.

Repeated deaths, moult problems or unusual weakness need experienced culture or veterinary advice. Record approximate numbers, growth and food use and review airflow, diet and climate. Identify associated organisms before treatment; do not use improvised insecticide or automatic mite removal.

Choose identified captive stock and retain any hybrid uncertainty. Confirm current import requirements and plan nymph containment and rehoming. Never release non-native cockroaches or occupied culture material outdoors.

Test nymph security, retreats and safe hydration before arrival. Check food, moisture and unusual losses regularly. Remove spoiled extras without sprays and review colony growth. Leave separate dry-food, fresh-food and water instructions for holiday care.