Oriental Cockroach

Facts

• Name: Oriental Cockroach, Blatta orientalis
• Life cycle: Incomplete metamorphosis
  Ootheca: Contains an average of 16 eggs; incubation ranges from 6 to 12 weeks depending on temperature and humidity
  Nymphs: Undergo 7-10 moults; development to adulthood typically takes 6-18 months
  Adults: Live for around 6 months. Males possess long wings that cover three-quarters of the abdomen, while females have short, non-functional wing stubs (brachypterous)
• Description:
  Adults measure 20–24 mm in length and range from reddish-brown to black with a glossy exoskeleton. Nymphs resemble adults but lack wings. Females are broader-bodied and wingless in appearance, while males are narrower with visible wings. Females typically produce up to five oothecae, which harden to a dark brown colour with dorsal indentations. Both sexes are flightless and slow-moving compared to other cockroach species.
• Behaviour:
  Primarily nocturnal, B. orientalis is a ground-dwelling species that avoids climbing smooth vertical surfaces. It is less agile than Blattella germanica and tends to congregate in undisturbed, humid areas. Known colloquially as “waterbugs,” they are often found near decaying organic matter and plumbing infrastructure.
• Habitat:

  Prefers cool, damp environments with temperatures between 20–29°C. Commonly found in basements, cellars, boiler rooms, and behind toilets, baths, and sinks. In the UK, it can survive outdoors but ceases breeding below 10°C. Globally, it is distributed across temperate and subtropical regions, often thriving in urban drainage systems, service ducts, and waste storage areas.