Adults are about 5/8 inch long (17mm). Adult German cockroaches are light brown except for the shield behind the head marked with two dark stripes, which run lengthwise on the body. Young roaches are wingless and nearly black with a single light stripe running down the middle of the back. Egg capsules are light tan.
German cockroaches, Blattella germanica (L.), are the most common roaches found in houses and restaurants. Most cockroaches have a flattened, oval shape, spiny legs, and long, filamentous antennae. Immature stages are smaller, have undeveloped wings and resemble the adults. They eat food of all kinds and may hitchhike into your house on egg cartons, soft drink cartons, sacks of potatoes or onions, used furniture, beer cases, etc.
German cockroach females, unlike most other roaches, carry the egg capsule protruding from their abdomen until the eggs are ready to hatch. The case is then placed in a secluded location, with the nymphs emerging one to two days later. A female may produce four to six cases during her lifetime, each containing 30 to 40 eggs. Eggs hatch in 28 to 30 days, and nymphs develop in 40 to 125 days. Female roaches live about 200 days and males not as long. The roach produces more eggs and has more generations per year (three to four) than other roaches, and only a few individuals are needed to develop into troublesome infestations.
They can develop into large populations and live throughout the house, especially in the kitchen and bathroom. During the day, these roaches may be found hiding clustered behind baseboard molding, in cracks around cabinets, closets or pantries, and in and under stoves, refrigerators and dishwashers, behind window and door frames, in radio and TV cabinets, and around closet and bookcase shelves. When seen during the day in clusters, the population is large.
Roaches can foul food, damage wallpaper and books, eat glue from furniture, and produce an unpleasant odor. Some homeowners are allergic to roaches. The pests can contaminate food with certain bacterial diseases that result in food poisoning, dysentery, or diarrhea.
Inspect sacks, cartons and boxes, etc., before they are brought into the house, and destroy any roaches. Sanitation is critical in roach control. Clean up spilled foods and liquids, avoid leaving scraps of food on unwashed dishes and counter tops, keep food in tightly sealed containers, rinse cans and bottles before putting them in trash and transfer garbage outdoors into roach-proof receptacles.
The American cockroach is the largest of the house-infesting roaches. They are most commonly found in restaurants, grocery stores, bakeries, breweries, pet shops and other establishments where food is prepared or stored. They are often found in damp sewers and basements, in heating ducts under hospitals, and on the first floors of buildings. They can be transported into homes and apartments in boxes from infested establishments. Roaches can foul food, damage wallpaper, books and clothing, and produce an unpleasant odor. Some home owners are allergic to roaches and the pests can contaminate food with certain bacterial diseases that result in food poisoning, dysentery, or diarrhea. Cockroaches can cause childhood asthma.
Most cockroaches have a flattened oval shape, spiny legs, and grow long, filamentous antennae. Immature stages are smaller, have undeveloped wings and resemble adults. Adult American cockroaches are reddish-brown to dark brown (except for a tan or light yellow band around the shield behind the head), about 1-1/2 to 2-inches long, and have wings capable of flight. Males and females are about the same size. The wings are about the same length as the body (abdomen) in the females and longer in the males, extending slightly beyond the abdomen. Females have a broader abdomen, while the males have both cerci (pair of appendages at the end of the abdomen) and styli (short, slender, fingerlike process). Nymphs are wingless, uniformly brown colored, and run very fast. Egg capsules are mahogany brown and about 1/3-inch long.
American cockroach females deposit their eggs in bean-shaped cases in sheltered areas on or near the floor, usually close to a food source. Egg capsules protrude from the body for a few hours to four days. One egg capsule is formed each week until 6 to 14 have been produced. Eggs hatch between 5 to 7 weeks, first into whitish-brown nymphs, later turning more reddish-brown. Development to adult averages about 15 months, varying between 9-1/2 to 20 months. These roaches are found in dark, moist areas, especially in sewers, steam heat tunnels, boiler rooms, around bathtubs and clothes hampers, and around plumbing, feeding on decaying organic matter. Cockroaches hide during the day in sheltered, dark places and forage for food at night, often running rapidly when disturbed. American cockroaches are one of the least common roaches found in homes and, though winged, seldom fly when disturbed.