Smokybrown Cockroach

🔤 Taxonomy

Periplaneta fuliginosa (Serville, 1838) is the accepted name. “Smokybrown cockroach” is normally written as one word in North American extension literature. Adults are uniformly glossy mahogany to nearly black, including the pronotum; this separates them from the pale-edged pronotum of P. americana and the yellow forewing stripe of P. australasiae.

Several large outdoor cockroaches are called “palmetto bugs,” so that label alone is not an identification.

📌 Description

Adults are about 2.5-3.2 cm, slender, fully winged, and strong fliers. Both sexes have wings extending beyond the abdomen. Nymphs are dark with temporary pale patches that change through successive instars.

Compared with other commonly cultured Periplaneta, this species makes particularly good use of vertical bark and humid tree-hole-like retreats. It is also prone to desiccation, attracted to light, and slow to mature; those traits require a different balance from a dry, fast-production feeder colony.

🌍 Distribution

The species is probably East Asian in origin and is widespread in China, Korea, and Japan. Commerce has introduced it to warm parts of the Americas and other regions, where it lives around tree holes, wood piles, gutters, attics, and humid exterior structures. The map highlights the probable East Asian source region rather than implying that introduced records are native.

Probable East Asian source region; introduced populations occur elsewhere

⚖️ Legal status

Checked on 2026-08-22: P. fuliginosa is not listed in CITES, EU wildlife-trade Annexes A-D, Bern Convention appendices, or the current EU Union list of invasive alien species. Domestic pest, biosecurity, import, transport, sale, landlord, and institutional rules may still prohibit or condition live colonies.

Obtain written guidance when the local status is unclear and keep proof of purchase. Never release the animals, and do not move oothecae, bark, or substrate into gardens or buildings where the species could establish.

🤌 Husbandry

Use at least 45 × 30 × 40 cm for a small colony, with fine cross-ventilation, gasketed lid, and multiple latches. The height supports bark climbing but also increases flight opportunity; keep all perches well below the opening. Service the box inside a tall smooth catch bin in a darkened, closed room.

Parameter	Practical target
Adult size	2.5-3.2 cm
Main temperature	24-28 °C; limited warm side 28-30 °C
Cool / night	20-24 °C
Humidity	65-80%, with airflow and a humid bark refuge
Substrate	5-7 cm leaf-rich and moisture-buffering
Development	slow; egg-to-adult may approach 600 days in average conditions

Quarantine additions for at least 60 days. Never mix visually similar Periplaneta. Their flying adults and oothecae make later separation impractical.

💡 Lighting

No UVB is needed. Provide a dim 10-12-hour cycle and complete daytime shelters. Smokybrown adults are attracted to lights; turn off bright lamps and cover windows before opening the enclosure. A faint indirect viewing light after dusk is safer than illuminating the open box.

Direct sunlight is dangerous because the dark body and closed container heat rapidly. Measure temperature at the upper bark as well as at substrate level.

🌡 Heating and temperature

Maintain 24-28 °C through the main area, with a small 28-30 °C warm side and a 20-24 °C refuge. Nights of 20-24 °C are suitable. UF/IFAS reports very temperature-dependent development averaging around 600 days from egg to adult, so slow growth alone is not evidence of failure.

Heat the room or side wall with a thermostat. Avoid uniformly hot conditions: they raise water demand, increase flight at maintenance, and can turn the upper bark stack into an unseen heat trap.

💧 Humidity and water

This species loses water readily. Maintain 65-80% relative humidity, a moist lower layer, and a humid cork hollow while preserving airflow and a dry feeding shelf. Dry antennae, repeated molt failures, or clustering tightly around water suggest inadequate moisture; condensation and sour substrate indicate excess.

Provide clean water continuously in a shallow textured dish protected from nymphs, plus moisture-rich vegetables. Do not rely on fruit alone, and do not seal vents to raise humidity.

🌿 Enclosure and decoration

Use 5-7 cm of pesticide-free soil/coir mixed with hardwood leaf litter and soft rotten hardwood. Build stable vertical cork hollows that resemble the narrow moist refuges used outdoors, but ensure every piece can be inspected. Include removable ootheca strips.

Avoid cedar, resinous bark, fertilizer, perlite, and décor taken from pesticide-treated gardens. Do not place branches against the lid or vent mesh. Inspect hollow bark over a catch tub before removal because both nymphs and egg cases can remain inside.

🪳 Feeding

Keep a balanced dry diet available and offer squash, carrot, sweet potato, greens, apple, pear, or other safe produce every one to two days. Add a modest fish-food or legume protein portion once or twice weekly. Leaf litter and soft rotten hardwood can remain as supplemental detritus.

Use feeding dishes on the drier shelf and remove wet leftovers in 24 hours. This reduces mites without drying the entire enclosure. Pest-capable P. fuliginosa should not be released into a reptile enclosure as an unattended feeder.

🥚 Breeding

A female averages about ten oothecae in a lifetime, each with roughly 20 eggs. She carries a new case briefly and then hides or attaches it. Incubation averages around 45 days in extension references; monitor for 35-60 days at 25-29 °C rather than discarding a case early.

Sex adults by terminal styli and abdomen shape. Offer sheltered removable strips, maintain humidity around the case without wet contact, and use a fine-mesh nursery when controlling hatchlings. Slow nymphal development means population planning must extend beyond a single season.

🩺 Common problems

Desiccation and failed molts: verify continuous water, the moist lower layer, and humidity inside the bark refuge.
Flight toward room lights: darken the room and close it before opening; never reach after a flying adult over an open box.
Slow growth: check measured warmth and food, but recognize the species’ long development before increasing heat.
Mold, mites, or flies: move food to the dry shelf, remove leftovers and corpses, and improve cross-ventilation.
Allergy: frass and shed cuticle can cause sensitization; moisten dusty waste and use gloves and suitable respiratory protection.

📌 Conclusion

P. fuliginosa suits a patient keeper who can combine a genuinely humid retreat with clean airflow and flight-proof maintenance. Its polished colour is best seen under dim light, and its slow life cycle never makes containment less urgent.