Oriental Cockroach

The Oriental cockroach, *Blatta orientalis*, is a nocturnal hemimetabolous insect belonging to the family Blattidae. Adults measure 25–30 mm (male) or 20–27 mm (female) and are uniform glossy black to dark reddish-brown, distinguishable by the females having greatly reduced, non-functional wings while males possess wings covering about three-quarters of the abdomen. The lifecycle typically spans 200–800 days from egg to adult at 25°C, with nymphs undergoing 6–10 instars over 130–300 days. Females produce 5–10 oothecae in their lifetime, each containing 12–18 eggs, which hatch after approximately 60 days. This species exhibits a lower optimal temperature range (around 20-29°C) and higher humidity tolerance (up to 90% RH) compared to other common peri-domestic cockroach species, allowing it to thrive in cooler, damper environments.

Primarily nocturnal, *B. orientalis* exhibits limited flight capability, particularly the females, and is typically a ground-dwelling species, preferring to crawl. They communicate through aggregation pheromones deposited in fecal trails, leading to localized infestations and encouraging communal harborage. Their feeding ecology is scavenger-generalist, consuming decaying organic matter, starches, and other refuse; however, they require regular access to water and can survive for weeks without food but only days without water. When disturbed or perceiving a threat, they will exhibit a thigmotactic response, flattening their bodies and disappearing into cracks and crevices. Public health impact stems from mechanical transmission of pathogens, including bacteria (e.g., *Salmonella* spp., *E. coli*) and viruses, by contact with their feces, body surfaces, and regurgitated food, particularly in food preparation and storage areas.