The American Cockroach is the largest species of common cockroach.They are reddish brown and have a yellowish margin on the body region behind the head. Immature cockroaches resemble adults except they are wingless. In residential areas, these cockroaches live in basements and sewers, and may move outdoors into yards during warm weather. These cockroaches are common in basements, crawl spaces, cracks and crevices of porches, foundations, and walkways adjacent to buildings.Cockroaches can pick up disease-causing bacteria, such as Salmonella, on their legs and later deposit them on foods and cause food infections or poisoning. House dust containing cockroach feces and body parts can trigger allergic reactions and asthma in certain individuals.
American cockroaches are one of the largest cockroaches that invade homes. Adults can be slightly more than 50 cm long.
Adult American cockroaches are reddish brown or mahogany colored. The area behind their heads is outlined with a yellow band. Immature American roach nymphs are grayish brown. As they mature, their color becomes more reddish brown.
Both male and female American cockroaches can fly. The wings develop when the roaches become adults.
Behavior, Diet & Habits
American cockroaches normally live outdoors. They prefer warm, damp areas like flowerbeds, and under mulch. In many parts of the United States people call them “palmetto bugs” because they live on trees. American cockroaches are very common in sewer systems of many American cities.
American cockroaches enter homes to find water or food. They can easily pass under doors if the weather stripping is damaged. Basement windows and garages are also common entryways. When American cockroaches enter homes, they often go to bathrooms, kitchens, laundry rooms and basements.
Outdoors, American cockroaches eat leaves, tiny wood particles, fungi and algae. They also eat small insects. Indoors, American cockroaches forage under appliances, in drains, in kitchen cabinets and on the floor. They eat crumbs, scraps of food and spilled food that they find. They will also eat pet food that is left out overnight.
Female American cockroaches make protective cases for their eggs. These cases are capsule-shaped. After forming a capsule, the roach deposits it in a warm, humid area. An average American roach egg capsule contains about 16 eggs.
When the eggs hatch, the tiny nymphs come out of the capsule. As they grow, the immature roaches shed their skins. If there is plenty of food, American cockroaches can develop from egg to adult in as little as 5½ months.
Signs of an American Cockroach Infestation
Homeowners may see these active cockroaches. American roaches can run very fast, and they usually scurry into a dark area. If they are startled, American roaches may even fly.
American cockroaches leave their droppings in the dark areas where they hide. Homeowners may find these droppings in basements, in pantries or behind appliances.
American cockroach droppings are small, and sometimes people mistake them for mouse droppings. American cockroach droppings have ridges on the sides and they are blunt on the ends. Mouse droppings have pointed ends. Since mice groom themselves, mouse droppings often have hairs embedded in them.
American cockroach egg cases are about 38 mm long. They are dark-colored—reddish or blackish brown. Homeowners often find these egg cases in basements, in laundry rooms or kitchens. The egg cases may be under cabinets or behind appliances. American cockroaches also deposit their egg capsules behind stored items in garages and sheds.
Cockroaches produce a chemical called an “aggregation pheromone.” The odor of this chemical causes the roaches to stay together in groups. Some people describe the odor of these pheromones as having a “musty” smell. As the roach population starts to grow, people with sensitive noses may begin to notice this odor.
They are a peridomestic species and live primarily outdoors. In southern states, they are common in shady, humid areas like flowerbeds and around trees. In northern areas, they are usually found in sewers and drains. Climate changes or food shortage can cause them to move indoors.
When they move indoors, American cockroaches prefer to live in moist, humid environments. They can also survive in dry areas with sufficient food and water sources. These insects favor temperatures between 70 and 80 degrees Fahrenheit. When an American cockroach population infests a human home, the insects are drawn to food storage and preparation areas, as well as moist locations. In industrial settings such as restaurants and bakeries, they can be found in boiler rooms and steam tunnels. In residential and commercial buildings, the American cockroach typically infests basements and landscaping.
American cockroaches are moderate flyers. They also gather together in open spaces, while other domestic cockroaches tend to hide in cracks and crevices. They do enjoy sweet foods, but prefer decaying material.