American Cockroach

American Cockroach   (Periplaneta americana)

Habitat

American cockroaches live primarily outdoors, but it’s not uncommon to find them inside a structure. American cockroaches are found in sewers, drains, and outside in shady-humid areas; such as mulch piles and flower beds. They will move indoors when they experience a food shortage or a significant change in the climate. In general, American cockroaches prefer warm, moist and dark environments with temperatures between 70 and 80 degrees. They often enter structures by being brought in on human belongings, coming up from the sewer system via drains or occasional mass migration from other structures, dumps, etc., during warm weather.

American cockroaches are especially common in commercial buildings such as restaurants, bakeries, grocery stores, food processing plants, hospitals, etc., where they usually infest food storage and food preparation areas, boiler rooms, and basements. These pests can also infest homes by easily passing underneath doors lacking weather stripping or entering through basement windows and garages. Once inside a residence, American cockroaches usually make their way into the kitchen, bathroom, basement or laundry room in search of food and water.

Food

American cockroaches feed on a variety of foods, with an apparent preference for decaying organic matter.  Indoors, they eat crumbs found under appliances, in drains, behind kitchen cabinets and on the floor. They will also eat pet food that is left uncovered. The adults can survive two or three months without food but only about a month without water.

Biology

Adults are approximately 1-1/2 inches long and reddish brown, with fully developed wings that cover the entire length of the abdomen. Both male and female are fully winged. The wings of the male extend slightly beyond the tip of the abdomen, while those of the female are about the same length as the abdomen. Nymphs are similar in appearance but are smaller and do not have wings. American cockroaches are capable of flying but rarely do in northern areas of the United States. The American cockroach can be identified by its large size and reddish brown color with faded yellow edges on the thorax. 

American cockroaches have three developmental stages: egg, nymph, and adult. The eggs are laid in capsules that are dark brown, symmetrically shaped, and about 5/16 inch long. The female drops her egg capsule within a day after it is formed. She often drops it in a suitable location near a food source or in a protected area. Each capsule averages 14 to 16 eggs. Usually one capsule is produced each week and is often glued to a hidden surface with secretions from the female’s mouth. Each female produces from 15 to 90 egg capsules. The length of the egg stage varies from 29 to 58 days. At room temperature, nymphs hatch out in 50 to 55 days. Young nymphs are grayish brown and after the first few molts become reddish brown. The nymphal stage varies in length from 160 to 971 days. The number of offspring per year averages 800. Under ideal conditions an adult female can live up to 15 months, males for a somewhat shorter period.

Threat

American cockroaches are filthy pests, and their presence in the home can pose a severe health threat. Cockroaches have been reported to spread at least 33 kinds of bacteria, including E. coli and Salmonella, as well as six kinds of parasitic worms and at least seven other kinds of human pathogens. They pick up germs on the spines of their legs and body as they crawl through decaying matter or sewage, and then transfer the germs onto food or cooking surfaces. The saliva, urine and fecal droppings from American cockroaches contain allergen proteins known to elicit allergic reactions and asthma attacks. As such, cockroaches are a common trigger of year-round allergy and asthma symptoms, especially in children.

Prevention

Having a clean and sanitary home will also make it less inviting to American cockroaches. Homeowners should keep counters, sinks, tables and floors free of clutter and crumbs. Don’t leave dishes pile up in the sink or spills marinate on the counter. It’s also good practice to store food in airtight containers, and avoid leaving pet food out in the open. Some other ways to prevent American cockroaches include vacuuming at least once a week to remove food particles, ventilating crawl spaces to prevent moisture buildup.