Oriental Cockroach
The Oriental cockroach known as the “water bug,” is more closely associated with damp areas than the other common roaches. These insects feed on garbage and decaying organic matter and are often considered the filthiest of the house-infesting roaches. They are found in damp basements, cellars, crawl spaces, near drains, leaky water pipes and beneath refrigerators, sinks and washing machines, under floors, and inside walls. They forage mostly on first floors of buildings. Outdoors, they are found beneath decomposing leaves or stones in mulching materials, in trash and at municipal sewer plants. During the autumn, there can be a mass movement into buildings, but because of their preference for cooler temperatures, can be found outdoors and in unheated buildings during the winter.
Most cockroaches have a flattened oval shape, spiny legs and grow long, filamentous antennae. Adult Oriental cockroaches are shiny, dark brown or black, about 1 to 1-1/4-inch long and have nonfunctional wings incapable of flight. Females are about 1-1/4-inch long, broad and have only little pads for wings. Males are about one inch long, more slender and have wings not reaching the tip of the abdomen. Immature roaches (nymphs) are darker in color than adults, similarly shaped and wingless. Egg cases are dark reddish-brown, one inch long (largest of the common roaches), and appear slightly inflated.
Oriental cockroach females (more numerous than males) carry the egg capsule 12 hours to 5 days and deposit them in a sheltered location near or within a food supply at a warm, sheltered spot. Females produce 1 to 18 capsules, each containing up to 16 eggs. Eggs hatch in about 60 days and nymphs develop in about one year. Adult females live 1 to 6 months. These roaches, most common during May, June and July, are more sluggish than the other common roaches, developing in damp basements and sewers and foraging mostly at or below ground level structures. They are usually not found in cupboards, on walls or on upper levels of buildings. They occur outside during warm weather, and, during cool periods, may migrate in masses indoors. They have a preference for high-moisture conditions. They can live without food for a month if water is present, but die in two weeks without food and water.
Oriental cockroaches feed on all kinds of filth, rubbish, and other decaying organic matter. They seem especially fond of garbage and the contents of discarded tin cans. If water is available, they can live for a month without food; without water they die within two weeks. The most important aspect of cockroach damage derives from their habit of feeding and harboring in damp and unsanitary places such as sewers, garbage disposals, kitchens, bathrooms, and indoor storage areas. 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.
Different forms of gastroenteritis (food poisoning, dysentery, diarrhea, etc.) appear to be the principal diseases transmitted by Oriental cockroaches. The insects carry these disease-causing organisms on their legs and bodies and deposit the organisms on food and utensils as they forage. 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.
Perimeter insecticide sprays may aid in the reduction of Oriental cockroaches entering homes from the exterior. Sprays should be applied as to create a continuous barrier around the structure. Oriental cockroaches may move into dwellings from the outside. Recent research has been conducted on the movement of Oriental cockroaches under, around, and into homes from harborages in crawl spaces and cinder block foundations. The research has shown that these cockroaches frequently move into the home along plumbing (e.g., up through the floor from underneath the crawl space) and under door or window jams.
