An affinity for moisture helps direct the infamous Oriental Cockroach into many unwanted areas.
Found in all three countries of North America, the Oriental Cockroach is not originally from the continent. Despite the common name, it may not even originally come from Asia either. Regardless of its origin, it has established itself as one of a handful of pest cockroach species. Its ordinary habitat is woodland leaf litter and other moist areas, but its innate attraction to water and moisture has led the species to more developed areas. Because of its affinity for wet terrain, it is also called a Waterbug. Populations of Oriental Cockroaches commonly infiltrate sewer systems and pipelines, crawling on pipes and entering homes, offices and other buildings through small openings, like those around pipes. They seek shelter in crawlspaces, cellars, and basements where high humidity is often normal. Once inside, they explore for food sources and sometimes hide in sink (kitchen and bathroom) and tub drain holes. Their sudden emergence from drains terrifies the best of us. They tolerate dry areas well enough to also hide under furniture, behind radiators, and in dark closets. This adaptability makes them a serious nuisance indoors. This is also the type of cockroach seen scurrying out from under outside containers, like garbage cans.
The average lifespan of an Oriental Cockroach is about 18 months. They mature the first year, molting many times until they become winged adults. Long-winged males and the short-winged females cannot actually fly though. After mating, dark, tubular egg sacs the size of Tic-Tacs called ootheca are wedged in cracks, crevices, and other hiding places to increase the chances of offspring survival. Each brown capsule can carry over a dozen tiny eggs. Both nymphs and adults feed on pretty much anything, even filth and sewage, but they are especially fond of starchy items like crumbs, cereal, cookies, and most foods stored in pantries or cupboards.
Infestations are difficult to control and may require multiple treatments, possibly from a professional. Finding and destroying egg capsules in tiny cracks is hard, even with spray insecticide, so it is reasonable to think complete eradication from a home or building may require months of applications to reduce the living adult population and then the younger, newly born nymphs. There are some things one can do to make it harder for Oriental Cockroaches to enter a building in the first place: seal gaps in door and window trim, as well as gaps around any incoming pipes. Use an appropriate insecticide to spray around the exterior and interior of the building. Fix water leaks, even small ones, to help keep areas dry and less attractive.
Chances are, however, if you are reading this, they have already found a way in. If they have infiltrated the premises, still consider making it harder for more to come in by plugging exterior gaps. Cockroach bait (i.e. 'roach motels') can poison adults and nymphs. Insecticidal sprays created just for cockroaches can help reduce their presence in sprayed areas. The destruction of ootheca is necessary to prevent reoccurring population booms, so look for and destroy any dark brown capsules hiding in corners, cracks in the floor or walls, and even in drains. Drain caps will prevent hiding adults or hatching nymphs from scaring people when water is turned on. Fortunately, this species of cockroach is a slow mover compared to others. This may be a small comfort in the event of an infestation, but it also means slippers and shoes are useful tools for reducing the population. If the situation seems beyond control, call in the professionals.
Scientific Name: Blatta orientalis
Other Name(s): Waterbug, Black Beetle
Size (Adult; Length): 18mm to 30mm (0.70in to 1.17in)
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