# Oriental cockroach

*Blatta orientalis*

**Identification confidence:** Identifiable with care

## How to recognise it

- Very dark, almost glossy black to deep reddish-brown, noticeably darker than any other common house cockroach.
- Females have only small wing pads and cannot fly; males have wings covering about three-quarters of the abdomen. Neither flies.
- Body is broad and somewhat flattened, 22 to 30 mm — between German and American cockroaches in size.
- Movement is slow and clumsy compared with other species.

## What it leaves behind

- Insects found in basements, crawl spaces, floor drains, and window wells, generally at or below grade.
- A strong musty odour associated with the harbourage area.

## Why an infestation persists

Strongly tied to cool, damp locations at or below grade — drains, sump pits, crawl spaces, and leaf litter against a foundation. They tolerate cooler conditions than other species, which is why they are the basement cockroach in northern states.


## Where it occurs

Across the northern and central United States and at higher elevations elsewhere; more cold-tolerant than other house cockroaches.

## What prevents it

- Correct standing water and chronic damp in basements and crawl spaces — this is the controlling factor.
- Keep drain traps filled and fit covers on floor drains.
- Remove leaf litter and dense ground cover from against the foundation.
- Seal gaps at grade, around window wells, and at utility entries.

## Commonly confused with

- **American cockroach** (*Periplaneta americana*) — Very large at 34 to 53 mm, the largest cockroach commonly found in US homes.
- **Smoky brown cockroach** (*Periplaneta fuliginosa*) — Uniform dark mahogany to near-black with a glossy sheen, and — importantly — no pale margin on the pronotum, which separates it from the American cockroach.

**Verdict:** prevention-first. Moisture and grade-level entry govern this species almost entirely; correcting both resolves most complaints.

Source: https://againstpest.shop/identify/cockroaches/oriental-cockroach/