Possibly from northern Africa or Asia, but found worldwide for many centuries now. It occurs throughout the United States as a common indoor and outdoor cockroach, and in some areas may be more common than the German roach.
This species is common outdoors in landscape plantings, in sewers or storm drain systems, and in lower areas of buildings where moisture may be greater. It may inhabit storm drains in huge numbers, emerging though man-hole covers at night to invade buildings. They will feed on most carbohydrate or protein based materials, including human hair or finger and toenails. Each female produces around 10 egg capsules, carrying the capsule for a day or two and then carefully placing it in a protected location. Each egg capsule has an average of 15 eggs in it and these hatch in about 45 days. Development to the adult stage averages about 450 days, but may take well over 2 years in colder climates. Adults live an average of around 1 year, but potentially can live almost 3 years.
The American roach adult has fully developed wings and is capable of some flight, usually from an upper location to a lower surface. It is reddish brown with a yellow ring around the prothorax. Adults may be up to 1.5 inches long from head to tail, with extremely long antennae. The cerci are long and thin, a character that separates the nymphs of American roaches from those of Oriental roaches.
Since this species is abundant outdoors, control begins with habit management in the outdoor areas. Removal of harborage sites under debris or piles of wood and discarded materials will reduce populations near a structure. Control of food and moisture sources outdoors and indoors are important.
Apparently the German roach originated in Africa, but was transported through early commerce to Europe and now is found throughout the world.
The German roach is a nocturnal animal, strongly avoids light, cannot fly, and in almost all situations will be found indoors. Infestations normally begin by the introduction of roaches in packages. The biological potential of this species is enormous, with females producing an average of 5 egg capsules in their lifetime, each with an average of 30 eggs in it. The time from egg to mature adult averages about 3 months, allowing 4 generations of the insects each year. Female adult roaches live for about 200 days. Females carry the egg capsule until one day before the eggs are to hatch, providing necessary moisture into the eggs. Her activity level is low while she is in this “gravid” stage. This species has a higher moisture requirement than many other species, and is most likely to be living near moisture sources and in humid areas. First instar nymphs often remain in hiding, feeding on the fecal material of other roaches. Older roaches are extremely variable in their diets, feeding on virtually any materials in a food environment. They may also nibble on human hair or finger and toenails.
The German roach is typical of the genus Blattella, with a tan to brownish color, small size, and two dark, longitudinal stripes on its prothorax. Adults reach about ½ inch in length, with wings that reach the end of the abdomen in females and just beyond the tip of the abdomen in males. Neither is capable of flight. Nymphs begin as extremely small insects and without any hint of wings. However, they do have the dark markings on the prothorax. This species may be distinguished from the Field roach by the color of the face, which is light brown in the German.
Successful control relies heavily on habitat modification to eliminate food and water resources and to close access to harborage sites. It also is dependent on an inspection to discover all harborages that need to be treated or eliminated.
Oriental roaches inhabit damp locations such as crawl spaces under structures or underground water and sewage systems. Their travel through such unsanitary habitats increases their potential as disease vectors. It may be common in outdoor environments and enter a structure on its own, by crawling under doors or through other exterior openings. Females carry their egg capsules for about one day, and then deposit the capsule in a secluded place. Each capsule has an average of 15 eggs, and the development from egg to mature adult takes about one year, although in some circumstances it has been observed to take about 2.5 years. The insects are nocturnal, avoid light, and neither sex can fly, although the male has well developed wings.
These are large roaches, with adults reaching about 1 inch in length. They are very dark brown to black, with the females having an oval shape. The wings of the males do not reach the end of the abdomen, and the wings on the females are reduced to short stubs at the back of the thorax. The nymphs of this species are very similar to nymphs of the American roach, but may be distinguished by their cerci. On the Oriental roach the cerci are short and somewhat widened, while on the American they are long and thin.
Since this species often enters structures by walking in or entering through drains of various kinds, entry points must be dealt with the exclude the insects. Removal of vegetation and harborage sites around the exterior of the building will reduce the presence near the structure.
If you have a roach problem and would like to have a Craig Thomas Pest Control, in partnership with Orkin Pest Control,representative speak to you, give us a call! Contact us by phone 800-255-6777, email for your free inspection today!
We at Craig Thomas Pest Control, Inc. are grateful to Univar Profession Products and Services for pest information incorporated into this work.