Plant & Pest Diagnostics

American Cockroach (Periplaneta americana)

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.

Identification

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, finger-like 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.

Control Measures

Integrated Pest Management (IPM)

Integrated Pest Management (IPM) is a systems approach that combines preventive techniques, non-chemical pest control methods, and the wise use of pesticides with preference for products that are least harmful to human health and the environment. It is not the total elimination of pesticides but an alternate approach to traditional pest control measures. Complete reliance, in the past, on pesticides alone for pest control allowed certain pests to develop resistance, created potential human exposure to harmful chemicals, produced unsound environmental contamination, and created a threat to non-target species and pesticide waste. IPM consists of routine inspection and monitoring with treatment only when pests are actually present, thus reducing traditional, routine pesticide application treatment (calendar date sprays) whether pests were present or not.

By following a cockroach IPM plan, cockroach activity is monitored using sticky traps or glue boards. These monitoring stations are placed throughout a structure where roaches are likely to be found such as in dark places along cabinets, walls, under appliances, on pipes, etc., and in bathrooms and kitchens. Any tight cracks about 3/8 inch or smaller are good cockroach habitats. Monitoring indicates whether roaches are present and if control practices are working. IPM tools include glue boards, baits, vacuum cleaners, caulking, insect growth regulators (IGRs), etc.

Detection

American cockroaches can be detected by examining the premises after dark with a flashlight. They occur in dark, damp, warm places, often near steam pipes, in sewers, grease traps, damp basements, etc. During the day, probing hiding places with a wire will expose roaches. Household sprays of pyrethrins applied to hiding places will flush out roaches, sometimes killing them if they contact the spray.

Prevention and Sanitation

American roaches can move from one building to the next during the summer, entering through cracks in foundations, around loose-fitting doors or windows, and along water and gas pipes. Seal openings with putty or plastic wood. Inspect sacks, cartons and boxes, etc., brought into the home 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 in trash and transfer garbage outdoors into roach-proof receptacles.

Insecticides

Apply chemicals at roach hiding places. Enter a dark room quietly, turn on the light and watch where the roaches run. Spot treat these hiding places and known pathways, especially under and behind loose baseboards or molding strips and around pipes or conduits along the walls and through it. Do not treat entire floors, walls, or ceilings. Surfaces where food is prepared should not be treated. Buildings with multiple dwellings usually require the treatment of each unit.

There are numerous cockroach insecticide formulations. Some are labeled “general use” for homeowner application, and others are labeled “restricted use” for professional pest control or licensed, certified pesticide applicators only. Before using any insecticide, always Read the Label and follow directions and safety precautions.

Dusts such as bendiocarb (Ficam D), boric acid powder, pyrethrins (Drione) or silica aerogel (Dri-Die) can be applied with a puff duster into hiding places normally hard to reach with a spray.

Sprays, either oil-based or water emulsion, are applied as spot or crack and crevice treatments. These include propoxur, acephate, chlorpyrifos, diazinon, permethrin or resmethrin. Only the licensed certified pest control applicator may apply bendioarb, propetamphos, trichlorfon, cyfluthrin, cypermethrin, deltamethrin, esfenvalerate, lambda-cyhalothrin, tralomethrin and bifenthrin. Insect growth regulators or IGRs include hydroprene (Gentrol) and pyriproxyfen (Archer, Nylar) which act on immature growth stages by contact or ingestion, disrupting molting and development to fertile adults. (A combination of an IGR followed up by use of a bait is often effective.) Some still use contact insecticides in mist or ULV (ultra-low volume) machines to treat the entire indoor area. Open all drawers and closet doors so roach hiding places can best be treated. However, the trend is toward less sprays and aerosols and more IGRs and baits.

Baits

Certain segments of the public such as schools, hospitals, and office buildings may prefer baits to sprays. Baits include pastes, gels, particle baits and bait stations.

Bait advantages include: low hazard (toxicity) to people; suited for sensitive accounts; IPM oriented; offer effective control. Disadvantages include: high bait cost; precise placement required; not cost effective in heavy roach infestations.

Sticky traps have openings at both ends with the inside surface covered with a very sticky adhesive and slow-release food attractant. Properly placed traps, to and from roach hiding and feeding areas, can catch numerous adults and nymphs daily, especially brown-banded and German cockroaches. Traps are best used along with preventive and insecticidal applications to monitor populations. Trapping can determine harborage areas and infestation severity, monitor effectiveness of pesticide applications, and detect any roach population increases which may require additional pesticide treatments.

Fumigation is seldom used but will clean out a cockroach infestation. It must be applied only by a licensed, certified pesticide applicator.

If a severe cockroach infestation develops or if you are in doubt as to the control measures to use, contact a reputable, licensed pest control firm who has the chemicals, training and experience to best do a thorough job.