Cockroaches

German Cockroaches

Adult German cockroaches are 1/2 to 5/8 inch long and tan to light brown. 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.

Brown Banded Cockroaches

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.

American Cockroaches

The American cockroach is typically the largest of the species common to New England. This species often becomes abundant in city dumps and is most common in the basements and steam tunnels of restaurants, bakeries, food-processing facilities, and grocery stores.

Adults are approximately 1-1/2 inches long and reddish brown, with fully developed wings that cover the entire length of the abdomen. Both male and female are fully winged. The wings of the male extend slightly beyond the tip of the abdomen, while those of the female are about the same length as the abdomen. Nymphs are similar in appearance but are smaller and do not have wings. American cockroaches are capable of flying but rarely do in northern areas of the United States. The American cockroach can be identified by its large size and reddish brown color with faded yellow edges on the thorax.

When indoors, the nymphs and adults are usually found in dark, warm and moist areas of basements and crawl spaces, and in and around bathtubs, clothes hampers, floor drains, pipe chases, and sewers. They are also common around the manholes of sewers, and on the undersides of metal covers over large sump pumps. In the north, this cockroach is often associated with steam heat tunnels. Where steam heat tunnels are not found, the American cockroach is restricted primarily to large institutional buildings. It has also been observed migrating from one building to another during warm months in the north. Occasionally, the cockroaches infest sanitary landfills and can survive Pennsylvania winters because of the warmth generated within the piles of trash.

American cockroaches feed on a variety of foods, with an apparent preference for decaying organic matter. The adults can survive two or three months without food but only about a month without water.

Cockroach Control

The standard method of treating for cockroaches has been to spray insecticides on baseboards and in cupboards, with the hope that cockroaches will crawl across the band of dried insecticide and the residue left from the application will kill them. We now know that this type of treatment is not very effective. Reasons why include:

• Cockroaches do not live behind baseboards, but live in dark, damp locations near food and water sources. Efforts to locate and treat these hiding places are much more effective.


• Insecticides are not 100 percent effective and, unless efforts are made to reduce food, water and harborage, populations of the prolific German cockroach are likely to rebound.


• Cockroaches species, including the German cockroach, have developed insecticidal resistance to many insecticides.


• Most insecticidal sprays, especially aerosol treatments, don't have much residual activity. This is also true of "bomb" type applications.

Tools and Tips for Success.

It is possible to eradicate cockroaches, but effort and persistence must be greater than their reproductive rate. To be successful, a multi-tactic approach must be used. This means not relying on a single strategy (like sprays), but using several types of control tactics.

• Sanitation efforts alone (eliminating food, water, harborage) may not be enough to eliminate a cockroach problem, but will reduce the population and make other control efforts work better.


• Getting rid of clutter is extremely important.


• Eliminating water and food will make roaches move farther to obtain them and come into contact with baits and other control tactics.


• Cleaning cupboards and under/around appliances is important. Keep a vacuum cleaner handy. Vacuuming roaches is an easy way to make a dent in the population. Just be sure to take the vacuum cleaner bag outside afterwards.


• Because roaches usually travel pretty close to where they hide, use sticky traps (glue boards) to see where roaches are hiding. Replace them when the surface is covered with roaches. Over time, glue boards will indicate how well controls are working and identify new infestations.


• The biggest improvement in controlling cockroaches in recent years is the availability of effective bait products. They are available in small plastic containers (bait stations) or as a dispensable gel. Baits use fipronil, hydamethylnon, boric acid or abamectin as their active ingredient. Use gel baits (best) or bait stations in areas where roaches are caught on sticky traps. Bait areas where roach specks are found—these are locations where roaches spend a lot of time.