Australian Cockroach – Periplaneta australasiae – This species is usually less than 1 1/4 inches long, and is reddish brown with yellow stripes along the front edge of either wing and a dark spot in the center of the ‘pronotum’ (the section just behind the head). These are found primarily in the south of the US, but have been found in northern homes and greenhouses, after having been brought up in shipping crates, plants, and the like. They feed predominantly on plant materials, but will feed on various starchy materials inside homes.
German Cockroach – Blattella germianica – This is the most commonly found cockroach in areas of human development. Adults are pale to brown, and are only about 1/2 to 5/8 inch long. They can be easily distinguished from other cockroaches due to the two dark stripes on the back of the thorax. Young cockroaches take varying amounts of time to mature, as the stages of development can repeat if necessary (to allow fuller growth, or regeneration of lost limbs or segments). If German cockroaches are seen during the daytime, it is an indication that either the population is so large that the available cracks to hide in are full, or food and water are in short supply. They are omnivorous, but do prefer to feed on fermented food and beverage residues. While they do have wings, this species cannot fly.
American Cockroach – Periplaneta americana – This is the largest of the common species of cockroach, growing to 1 1/2 inches or more in length. They are reddish brown with a pale brown or yellow border on the ‘pronotum’ (the rear portion of the thorax). This variety is more often found in dark, moist areas, such as basements and crawlspaces, in and around bathtubs, clothes hampers, pipe chases, and sewers. They are general feeders, but seem to prefer decaying organic matter. They will also feed on book bindings, clothing, paper, or other starch-based materials. Sweeteners are also common to their diet (sugar, syrup, candy, and the like). This cockroach has well-developed wings, and has been known to fly short distances (or glide for longer ones).
Oriental Cockroach – Blatta orientalis – This cockroach is usually between 1 and 1 1/4 inches long. The female has smaller wings than the male, however neither sex can fly. The adults are dark brown or black, and look almost greasy in appearance. Oriental cockroaches feed on garbage and decaying organic matter. With water, they can live without food for as long as a month. They are common in high moisture areas, such as sewers, water meter enclosures, drains, and damp basements, and are most often not found in higher cupboards, on walls, or in the upper floors of buildings. When found indoors, they are commonly found in bathtubs, as their footpads cannot grip the porcelain or ceramic of the tub, trapping them inside.
