There are at least 25 species of cockroaches in Alabama, but only five are serious pests. Cockroaches are also known as palmetto bugs, water bugs, and croton bugs. They vary somewhat in appearance and habits, but in general they are all rather large, flattened insects, brownish or dark in color and fast moving. Roaches seek concealment in the daytime and also when disturbed at night. Most cockroaches are found outdoors. Outdoors, cockroaches are an important source of food for many forms of wildlife. They are also important in nutrient recycling. However, when indoors, cockroaches are a public health nuisance. They can serve as mechanical vectors for bacteria, protozoa, and viruses that can cause different forms of gastroenteritis in humans (food poisoning, dysentery, diarrhea, etc.).
Cockroaches can feed upon a great variety of materials such as cheese, beer, leather, bakery products, starch in book bindings, manuscripts, glue, hair, flakes of dried skin, dead animals, plant materials, soiled clothing, and glossy paper with starch sizing. The most important aspect of cockroach damage derives from the insects’ habit of feeding and harboring in damp and unsanitary places such as sewers, garbage disposals, kitchens, bathrooms, and indoor storage indoors. Filth from these sources is spread by cockroaches to food supplies, food preparation surfaces, dishes, utensils, and other surfaces. Cockroaches contaminate far more food than they are able to eat.
Cockroach excrement and cast skins also contain a number of allergens, to which many people exhibit allergic responses such as skin rashes, watery eyes, congestion of nasal passages, asthma, and sneezing.
There are five kinds of cockroaches commonly found in Alabama:
- The German roach is a very common species and the one usually found in kitchens. The adults are comparatively small (about 1/2 inch long), tan in color and often occur in large numbers. The immatures (nymphs) have dark markings which make them appear dark brown to black.
- The American roach is reddish-brown and is the largest of the common roaches (about 1-1/2 inches in length at maturity). It is found more often in food establishments, although houses and apartments near such establishments frequently become infested.
- The Oriental roach is also large (about 1 inch in length) and shiny black or very dark brown. It is often called a “water bug” or “black beetle.” This species is frequently found in dampness and may enter homes through sewer openings. It may likewise live outdoors during the summer months and move from home to home.
- The brown-banded roach is a southern species but is often found in Indiana. It resembles the German roach in size but differs in habits. It may infest the entire home, rather than confining itself to the kitchen or where there is food. Infestations usually start from luggage, furniture or other materials shipped from one place to another.
- The woods roach normally lives under the loose bark of dead trees, logs or stumps. It sometimes invades homes built in or near wooded areas, but it does not thrive indoors. Males are nearly 1 inch long and dark brown with a pale stripe on the outer margins of the wings. They are fairly good fliers and often enter homes this way. They can also be carried in on firewood. The females are short-winged and resemble the Oriental roach, but they are seldom found indoors.
CONTROL MEASURES AND MATERIALS
The chances of effective, lasting cockroach control are greatly increased when an integrated approach is used. Sanitation and exclusion precedes proper chemical application. The destruction of breeding places (by clearing out garbage and clutter, sealing cracks and openings, etc.) and the removal of food and water sources may reduce the necessity for chemical applications. When chemical applications are necessary, they must be applied strictly according to their labels and based upon the biology of the species. Evaluation after application is necessary to determine success.
Sources and more information: http://www.aces.edu/pubs/docs/A/ANR-1016/ANR-1016.pdf http://ento.psu.edu/extension/factsheets/american-cockroaches http://extension.entm.purdue.edu/publications/E-23.pdf http://extension.entm.purdue.edu/publications/E-241.pdf