Vector Borne Disease Control-Cockroaches

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Cockroaches have been found to be mechanical carriers of many diseases including staphylococcus, Escherichia coli (E. Coli), Salmonella food poisoning, and streptococcus. They carry bacteria around on their legs, and bodies. Pathogenic bacteria have also been identified in the feces of cockroaches. The most common cockroaches found within the human habitations in this area are the German cockroach, and the Oriental cockroach.

Cockroaches go through an incomplete metamorphosis, that is, they do not have a pupal stage. After hatching from an egg, cockroaches go through several nymphal stages before becoming adults. The nymphs are smaller than the adults, are a lighter color, and are broader in proportion to their length..

Adult German cockroaches are about ½ inch long. Males are grayish-tan with two black stripes on the front part of the back, and have a tapering abdomen. Females are usually darker, and their abdomens are more rounded. The egg capsule of the German cockroach is about 1/4 inch long. Half of it protrudes from the female’s abdomen, and it is carried this way until it is dropped, about one day before the eggs hatch. The female produces four to eight egg cases during its lifetime, each containing 30 to 48 eggs. The eggs hatch in about one month. The nymphs grow to adulthood in one and a half to four months. Adult cockroaches live about six months.

German cockroaches live in areas of high humidity, and nearby food. They like harborage into which they can fit closely, which means tight spaces. Places where there are plumbing leaks and standing water, such as in kitchens and bathrooms, provide favorable humidity levels. German cockroaches will leave favorable harborage under population pressure, or if something causes conditions to change unfavorably for them, such as pesticide applications.

The continued presence of cockroaches may be due to poor housekeeping on the premises, or on nearby premises. Cockroaches can best be controlled by maintaining scrupulous cleanliness, by removing sources of food and water, and by the proper disposal of garbage. Spraying pesticides, or setting bait will do little good if conditions remain favorable for them. Spraying and baiting should only be performed after the premises have been thoroughly cleaned, and their sources of food and water have been removed.

The Oriental cockroach is also known as the "water bug". Adult Oriental cockroaches are very dark brown, or shiny black. The female is one and a quarter inch long; the male is one inch long. The egg capsule is irregularly shaped, black, and 3/8 inch long. The female does not have wings. The male has short wings which leave part of the abdomen exposed. Oriental cockroaches prefer crawl spaces, basements, floor drains, and other moist places. These cockroaches can enter homes through the floor drain. They prefer starchy food, and build up populations around garbage cans.

Oriental cockroach females produce one to eighteen egg cases. Each case contains up to sixteen eggs. The eggs hatch in about sixty days. Nymphs develop into adults in about one year. Adults live one to six months.

Oriental cockroaches can be controlled by ventilating moist spaces, stopping water leaks, keeping water away from buildings, keeping drain traps full or covered, caulking cracks in walls, and moving garbage cans away from moist habitat. Pesticide applications can also be used to control Oriental cockroaches.

The application of pesticides is best performed by a trained professional. The misapplication of pesticides will quickly result in breeding pesticide resistant pests, which will make controlling them more difficult. In apartment buildings, control measures should be applied throughout the building in order to achieve effective control. If only a single unit in an apartment building is treated with pesticides, then cockroaches will be driven to other parts of the building. Holes and cracks in walls, floors, ceilings, and around pipes should be sealed to prevent cockroaches from migrating from one part of a building to another.

The Health District regulates cockroach infestations within rental properties under Public Health Nuisance Regulation 2-93, Section 7D. In cases where cockroach infestations have been found within a rental property the Health District can order the property owner to initiate control measures.

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