Cockroaches are found throughout the United States. Although they have not been found to transmit disease organisms, their movement in food preparation and serving areas allows the spread of pathogens that cause diarrhea, food poisoning and dysentery. They contaminate food with their droppings, their bodies, and the bacteria they carry.
Cockroaches also secrete a musty oil-based liquid that ruins food and gives an offensive odor to furniture, clothing and other articles. Their secretions and cast skins have been implicated as one of the causes of asthma in people, and their presence is often considered repulsive.
Cockroaches have chewing mouthparts. They feed on a variety of plant and animal products, including meats, grease, starchy foods, sweets and unprotected kitchen foods. They sometimes consume leather, wallpaper paste and other materials.
Cockroaches prefer warm, dark, humid conditions and are often found in sewers or in cracks and crevices around cupboards, drainboards and baseboards.
Cockroaches are important economically because of the large amount of foodstuffs they contaminate. Although they normally thrive in unsanitary conditions, even sanitary structures and establishments can become infested because these insects readily spread through adjoining buildings.
Cockroaches have three distinct life stages: the egg, several nymphal stages and the adult. Fertilized adult females produce small bean-like capsules that contain many eggs. These capsules, called oothoeca, may be dropped or glued onto surfaces by the female.
The nymphs emerging from the eggs resemble adult cockroaches but are smaller and have undeveloped wings. Cockroaches undergo several nymphal stages before reaching the adult stage. The life cycle Egg case may require 3 months to 3 years, depending on the species and environmental conditions
When infestations are small, live cockroaches may never be seen because they are most active at night. However, there are other ways to detect the presence of cockroaches. They have a characteristic "musty" odor, which may be strong in places they visit often. Other signs of cockroach infestations may include excrement, full or empty autmphegg cases and occasionally the skin shed by the nymphs. Excrement left by smaller species may appear as greasy smudges, that of the larger species resembles mouse droppings.
About 3,500 cockroach species have been identified worldwide. The majority of these species are not considered pests and often provide the essential service of recycling nutrients back into the ecosystem. However, some species have become adapted to living with and depending on humans for their survival. Due to their behavior and their associated pathogens these species are consisted pests.
Many species become pests when they are taken out of their native habitat and introduced into a foreign one. Cockroaches, or other insects that are introduced in this manner, and then thrive are known as an invasive species. One such cockroach species has been detected in Houston, and appears to be thriving along Buffalo Bayou west of Interstate Highway Loop 610. It is the Asian cockroach. It closely resembles the German cockroach, but is differentiated by its behavior and the underside of its' wings. The Asian cockroach prefers an outdoor habitat, is attracted to lights, and is a strong flier.