Cockroaches are among the most common of insects. Fossil evidence indicates that cockroaches have been on earth for over 300 million years. They are considered one of the most successful groups of animals. Because cockroaches are so adaptable, they have successfully adjusted to living with humans. About 3,500 species of cockroaches exist worldwide, with 55 species found in the United States. Only four species are common pests in San Diego structures. These are the German, brown-banded, Oriental, and American cockroaches. A fifth species, the Pennsylvania wood cockroach is an occasional nuisance pest in some locations.
Brown Banded Cockroach
Description and Behavior
Adult male brownbanded cockroaches are about 1/2 inch long and light brown, with fully developed wings . The adult females are shorter and stouter than the males and their wings do not cover the entire abdomen. Both adults and nymphs can be distinguished by the two brownish, broad bands across the body at the base of the abdomen and at mid-abdomen. Both males and females are quite active; adult males fly readily when disturbed.
Brownbanded cockroaches prefer warm and dry locations, such as near refrigerator motor housings, on the upper walls of cabinets, and inside pantries, closets, dressers, and furniture in general. They can also be found behind picture frames and beneath tables and chairs, and inside clocks, radios, light switch plates, doorframes, and dressers. It is common to find them hiding nearer the ceiling than the floor and away from water sources. Accurate identification is paramount to controlling brownbanded cockroaches. Control strategies for other cockroaches will not be efficacious for brownbanded cockroaches.
The German cockroach is a widely distributed urban pest. It is also the most common cockroach species in houses, apartments, restaurants, hotels, and other institutions. This is true not only in Pennsylvania but also throughout the United States and in most parts of the civilized world.
Adult German cockroaches are 1/2 to 5/8 inch long and tan to light brown (Fig. 1). Although they have fully developed wings, they do not fly. Nymphs are similar in appearance to adults except that they are smaller and lack wings. The German cockroach is best identified by its small size and by two dark parallel lines running from the back of the head to the wings. It is usually found in kitchens (near dishwashers, stoves, and sinks) and in bathrooms of homes.
German cockroaches usually prefer a moist environment with a relatively high degree of warmth. The insects are mostly scavengers and will feed on a wide variety of foods. They are especially fond of starches, sweets, grease, and meat products. In many locations, garbage is a principal food source. As with other species, German cockroaches are mostly active at night, when they forage for food, water, and mates. During the day they hide in cracks and crevices and other dark sites that provide a warm and humid environment. Their relatively wide, flat bodies enable them to move in and out of cracks and narrow openings with ease. They may be seen during the daytime, particularly if a heavy population is present or if there is some other stress, such as a lack of food or water or an application of pesticides.
The German cockroach is the most successful of the species infesting buildings in Pennsylvania. There are several reasons for this cockroach’s persistence and the difficulty of controlling it. German cockroaches produce a larger number of eggs per capsule and they undergo the shortest time from hatching until sexual maturity, resulting in a rapid population growth. A greater number of nymphs hatch successfully because the female carries the egg capsule during the entire time the embryos are developing within the eggs. Also, and most importantly, German cockroaches are smaller than most other cockroaches and can conceal themselves in many places inaccessible to individuals of the larger species.
Oriental cockroaches are often called water bugs because of their preference for dark, damp, and cool areas such as those under sinks and washing machines, and in damp basements. This species, which is less wary and more sluggish than the others, of concern because it often travels through sewer pipes and lives on filth.
Adult Oriental cockroaches are about one inch in length (Fig. 1). Both male and female adults are very dark brown, nearly black; their bodies usually have a somewhat greasy sheen. Females have small, functionless, rudimentary wing pads and broader, heavier bodies. Males have wings that cover only about three-quarters of their abdomen. Males are apparently unable to fly.
Nymphs and adults have similar habits and are found with decaying organic matter indoors and out. Indoors, Oriental cockroaches prefer dark, moist areas such as under porches, sewers, drains, crawl spaces, dark, damp basements, and floor drains. They can be found outdoors in abandoned cisterns and water valve pits; in yards; beneath leaves; in bark mulch around shrubs, flowers, and foundations; in dumps, stone walls, and crawl spaces; and in garbage and trash dumps and trash chutes. Both nymphs and adults are sluggish and are usually situated at or below ground level indoors. They are seldom found on walls, in high cupboards, or in the upper floors of buildings. At times large numbers occur in one great mass around leaks in the basement or crawl space areas of homes. Oriental cockroaches are generally found outdoors during warm weather, but in periods of drought there may be considerable movement into structures, apparently in search of higher humidity. They may enter the home in food packages and laundry, or merely come in under the door or through air ducts, garbage chutes, or ventilators.
Smokey Brown Cockroach
This roach, which is called a “water bug” by many locals or a “tree roach” by people who live in Highland Park is really a cockroach of major proportions.
Adults are 1 to 1-1/4 in. and are brownish-black in color, have wings, can fly and are attracted to light. Instars (juveniles) have distinctive colors, shapes and bear limited resemblance to the adults.
Common habitats are loose mulch, ground ivy, woodpiles, and the soffits/eaves of attics. They can be carried into homes, but usually enter at night via small cracks and crevices where light penetrates to the outside. Once inside, they tend to prefer warm and humid areas that are not exposed to air currents.
They feed on any kind of organic matter and can do minor damage to indoor plants. Primarily a night feeder, it is not uncommon for the homeowner to find them in the kitchen or pet feeding areas in the middle of the night. They can be very prosperous and flourish in huge numbers by feeding on dog droppings left in the yard.
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.
Life Cycle and Habits
American cockroach females deposit their eggs in bean-shaped cases (oothecae) 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. Each case contains up to 16 white or yellowish-white eggs. 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. Adults live almost 15 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. Many are attracted to fermenting liquid (bread saturated with beer). Feeding can occur on starch sizing in books, papers, etc. 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. Instead, there is more of a gliding flight. Adults can live at least two to three months without food, a month without water, and can easily survive outdoor freezing temperatures. Some have been found in alleyways and yards in summer months and around street lights.
Coastal Pest Solutions serves San Diego and beyond:
Mission Beach cockroach removal
Pacific Beach cockroach removal
Clairemont cockroach removal
Bird Rock cockroach removal
La Jolla cockroach removal
Scripps Ranch cockroach removal
Ocean Beach cockroach removal
Point Loma cockroach removal