The German cockroaches are the most common species in Utah. Adults are pale brown to tan and about 1/2 inch in length. Adults have wings and are distinguished by having two dark stripes that run lengthwise along the pronotum that is located at the back or top of the head. This species has the highest reproduction potential, mean it is capable of laying the greatest number of eggs in the shortest life cycle, of all the house infesting cockroaches.
Females carry their egg capsule protruding from their abdomen until the eggs are ready to hatch. Females produce 4 to 8 capsules in their lifetime. Each capsule contains 30 to 50 eggs, which hatch in about 28 days at room temperature. The eggs usually die if the mother is killed. Females usually live an average of 250 days. German cockroaches are generally found close to moisture and food, such as in kitchens and other food areas, restrooms, and around plumbing fixtures. Infestations found scattered throughout a building, including nonfood areas, indicate very high populations.
Cockroaches are oval, flattened, fast moving insects. They have long, hair like antenna and a broad, saddlelike plate called a pronotum that covers the head. Adult stages of most species have wings, with the front pair of wings being thick and leathery. Cockroaches go through gradual metamorphosis in three stages consisting of egg, nymph, and adult. The eggs are laid in bean like egg capsules called ootheca, which may contain several dozen eggs. These egg capsules are often dropped around food sources or secured to surfaces. Some cockroaches carry the ootheca during its development.
The immature stages are called nymphs. Several nymphal stages occur, each separated by a molt. The nymphs generally appear similar to the adult stage, but they lack wings and are smaller. Typically it requires 2 to 3 months to complete a life cycle.
Cockroaches are among the oldest insects known, with fossils dating back 200 million years. As a group, the cockroaches have shown exceptional ability to adapt to and survive in a wide range of environments. Most cockroaches can develop on a wide range of food and their flattened body form allows them to move into most areas. Cockroaches have also developed a resistance to many commonly used insecticides.
Cockroaches can enter buildings and containers of all kinds. They also may enter around loose fitting doors, windows, and through utility lines, and they may travel through sewers. Once within a home, cockroaches tend to prefer warm, dark, moist shelters and are often found near kitchens and food handling areas. Since cockroaches are nocturnal they are rarely seen during the day.
Aside from their reputation as a household nuisance, they may soil areas with their salivary secretions and excrement, leaving an unpleasant odor. Cockroaches and cockroach parts also produce allergic reactions in some humans. Cockroaches have not been found to be direct carriers of human disease. However, their feeding on filth or disease organisms is why they often contaminate food and utensils. They are suspected of helping to spread diseases such as dysentery, diarrhea, and food poisoning.
Most cockroaches are tropical or subtropical in origin and possess generally harmless habits. A few have developed into serious pests, including several species of cockroaches that have been introduced into Utah. The habits of common cockroaches are as follows.
Oriental cockroaches are not as common in Utah as the brown banded cockroach and the German cockroach. Adults are about 1 inch in length and dark brown or black in color. Wings of the oriental cockroach are short. Females only have small wing pads, while males have wings that only cover about 3/4 of their abdomen.
Females drop egg capsules in warm, sheltered areas near a food supply. Each female produces an average of 8 egg capsules, each containing about 160 eggs. Under room temperature conditions, eggs hatch in about 60 days. Adult females may live about 180 days. Oriental cockroaches are almost always found around moist, dark sites. Common habitats include floor and storm drains, water meter boxes, around plumbing fixtures, moist crawl spaces, sewers, and around garbage.
Oriental cockroaches are referred to as waterbugs and may be found outdoors during warmer months of the year. Oriental cockroaches are rather sociable, and clusters of them may be found in favorable habitats. They are seldom found high on walls, in high cupboards, or in the upper floors of buildings.
Brown banded cockroaches are slightly smaller than the German cockroach and are the smallest cockroach found in Utah, brown banded cockroaches vary from light tan to glossy dark brown in color. The adult stages are marked with two light colored bands at the base of the wings. Brown banded cockroaches usually secure their egg capsules to surfaces in dark areas such as cabinets, chairs, boxes, drawers, and high areas of building. This is why the eggs are easily transported to new buildings.
Females produce about 14 capsules during their lifetime, averaging 18 eggs in each capsule. Eggs hatch in about 50 to 75 days. The adult female may typically live about 200 days. Brown banded cockroaches tend to scatter thoroughly throughout a building. They prefer areas with temperatures of 80 degrees or higher. Brown banded cockroaches tend to occur more often in homes, apartments, hotels, and hospitals than in stores or restaurants.
BROWN BANDED COCKROACH
BIOLOGY AND BEHAVIOR