© Stuart M Bennett 2003
Periplaneta americana
(American Cockroach)


The American cockroach is the largest of the common species, growing to a length of 1-1/2 inches or more. It's dark red to dark brown in color, with light markings on the thorax. Both sexes are fully winged, the male's wings extending beyond the tip of the abdomen while the female's are about the same length as the abdomen. Females drop their oothecae within a day after they are formed. Oothecae may simply be dropped in a suitable location or glued to some surface with oral secretions. Oothecae are formed at the rate of about one per week until 15 to 90 capsules are produced.

Each ootheca contains 14 to 16 eggs. At room temperature, nymphs hatch out in 45 to 55 days. As they hatch, the nymphs molt, leaving thin cast skins in the egg case. Under ideal conditions, nymphs can reach maturity in 5 months. However, under adverse conditions, 12-24 months may be required for sexually mature adults to develop.

American cockroaches prefer a warm, moist habitat. They're common in food-handling establishments and industrial plants. Outdoors, in countries which have the climate, they live under tree bark, in sewers, or in underground utility chases. This species may travel directly from the sewer to your home carrying organisms on its body and legs that could contaminate your food and kitchen surfaces.

Female cockroaches glue or drop 1/4 inch long bean-like egg capsules containing about 6-28 eggs on or around infested areas. Nymphs hatch from the egg case that resemble small grayish-brown adult cockroaches without fully developed wings. Nymphs molt 7 to 13 times in over a year (470 to 600 days, depending on temperature) before becoming adults.

Cockroaches have dorsoventrally flattened bodies that allow them to enter homes through cracks around loose-fitting doors and windows, and where electric lines or pipes pass through walls. They are mainly active at night and hide in cracks and crevices during the day, preferring dark moist sites in attics and basements. Cockroaches eat almost anything including meats and grease, starchy foods, sweets, baked goods, leather, wallpaper paste, book bindings and sizing. Adults are capable of gliding flights.


  • This chap is 28 - 44 mm long.
  • It is coloured a shiny reddish brown.
  • Both sexes have wings in the male they are longer than the body, and in the female they only just overlap the abdomen.
  • The oothecae are carried by the female for several days before being deposited, sometimes in groups, and tend to be cemented down.
  • The lady cockroach can produce between 10 - 15 oothecae.
  • The numbers of eggs per oothecae vary quite a lot. i.e. 6 - 28.
  • The hatching time of the oothecae is 1 - 2 months.
  • The nymphs will moult their skins anything from 7 to 13 times before becoming adults.
  • The nymphal development time is usually 5 months, but can be as long as 15 months.



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