Oriental Cockroach

Actual Size: 1″ to 1 1/4″

Characteristics: Oriental roaches are relatively large and reddish-brown to black.


  • Oriental Cockroaches can be present in both commercial facilities and some residential homes.
  • Indoors, these “waterbugs” become very abundant in damp, secluded places such as crawlspaces, basements, and sump pumps.
  • They prefer to feed on starchy foods and decaying organic matter.
  • They are not very abundant outside in our northern climes.

Oriental Cockroaches in Southern California

The oriental cockroach is often referred to as the “black beetle” or “water bug” and is a major pest throughout the United States. Very much like other cockroach species, the oriental roach is attracted to wet and shady perimeter areas and prefers the dark and dampness of basements, cellars, and crawl spaces. Oriental cockroaches are known to climb water pipes and garbage chutes to access upper floors of apartment buildings. They feed on all kinds of filth, debris, and other decaying organic matter and seem especially fond of garbage and the contents of discarded tin cans. For this reason, they can frequently be seen in Los Angeles due to the city-living lifestyle.

Oriental Cockroach Habitat

Oriental cockroaches are common outdoors and live in warm, damp shady areas near the ground. Outside the house, these cockroaches will gather near or under trash cans. When temperatures drop, they may seek shelter indoors, but can tolerate cooler weather. Oriental cockroaches may enter homes in food packages from grocery stores or gain access under exterior doors, garage doors, through air ducts and ventilators. Inside, they tend to remain on lower floors and move more slowly than other species. The most common areas to find oriental cockroaches in homes are toilets, bathtubs, sinks, radiators and pipes. Unlike other types of roaches, oriental cockroaches are seasonal–adults typically can be seen from May to July.

Oriental Cockroach Threats

Oriental cockroaches rarely bite and are not a structural pest in that they do not damage homes. However, they still pose a big threat to health. Oriental cockroaches are known to carry at least 33 different kinds of bacteria, including e. Coli and salmonella. Cockroaches contaminate food items and the surfaces in our homes with harmful bacteria as they forage for food. They also pose a major threat to people with allergies or asthma as their shed skins and feces can cause serious reactions in these individuals. For this reason, always contact your local cockroach exterminators for help.