The American cockroach (Periplaneta americana) is the largest species of cockroach routinely found in homes, and often considered a pest. In certain regions of the U.S. it is colloquially known as the waterbug, though it is not a true waterbug since it is not aquatic, nor a Hemipteran. It is also known as the ship cockroach, kakerlac, and Bombay canary.
Despite their name, American cockroaches are native to Africa and the Middle East. They are believed to have been introduced to the Americas only from the 17th century onward as a result of human commercial patterns,
Distribution
Despite the name, none of the Periplaneta species is native to the Americas; P. americana was introduced to what is now the United States from Africa as early as 1625. They are reddish brown and have a yellowish margin on the pronotum, the body region behind the head. Immature cockroaches resemble adults, except that they are wingless.
The cockroach is divided into three sections; the body is flattened and broadly oval, with a shield-like pronotum covering its head. A pronotum is a plate-like structure that covers all or part of the dorsal surface of the thorax of certain insects. They also have chewing mouth parts, long, segmented antennae, and leathery fore wings with delicate hind wings. The third section of the cockroach is the abdomen.
The insect can travel quickly, often darting out of sight when a threat is perceived, and can fit into small cracks and under doors despite its fairly large size. It is considered one of the fastest-running insects.
In an experiment, a P. americana registered a record speed of , about 50 body lengths per second, which would be comparable to a human running at .
It has a pair of large compound eyes, each having over 3,500 individual lenses (ommatidia, hexagonal apertures which provide a kind of vision known as mosaic vision, with more sensitivity but less resolution, particularly useful at night, hence called nocturnal vision). It is a very active night insect that shuns light.
American cockroach nymphs are capable of limb regeneration. Females produce an egg case (ootheca) which protrudes from the tip of the abdomen. On average, females produce 9–10 oothecae, although they can sometimes produce as many as 90. After about two days, the egg cases are placed on a surface in a safe location. Egg cases are about long, brown, and purse-shaped. Immature cockroaches emerge from egg cases in 6–8 weeks and require 6–12 months to mature. After hatching, the nymphs feed and undergo a series of 13 moultings (or ecdysis). Adult cockroaches can live up to an additional year, during which females produce an average of 150 young. The American cockroach reproductive cycle can last up to 600 days.
Parthenogenesis
When female American cockroaches are housed in groups, this close association promotes facultative parthenogenic reproduction. The oothecae are produced asexually, without fertilization. during automixis, meiosis occurs, but instead of giving rise to haploid gametes as ordinarily happens, diploid gametes are produced (probably by terminal fusion of meiotic products) that can then develop into female cockroaches. Eggs produced by parthenogenesis have lower viability than eggs produced by sexual reproduction. These traits, along with enlarged groups of genes relating to detoxification, the immune system, and growth and reproduction, are believed to be part of the reasons behind the cockroach's ability to adapt to human living spaces.
Diet
American cockroaches are omnivorous and opportunistic feeders that eat materials such as cheese, sweets, beer, tea, 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. They have also been observed to feed upon dead or wounded cockroaches of their own or other species.
Flight
In the immature (nymph) stage, American cockroaches are wingless and incapable of flight. Adults have useful wings and can fly for short distances. If they start from a high place, such as a tree, they can glide for some distance. However, despite their ability to do so, American cockroaches aren't regular fliers. They can run very fast and, when frightened, these insects more commonly scatter on foot.
Habitat
thumb|Anatomy
American cockroaches generally live in moist areas but can survive in dry areas if they have access to water. They prefer high temperatures around and do not tolerate low temperatures. These cockroaches are common in basements, crawl spaces, cracks and crevices of porches, foundations, and walkways adjacent to buildings. In residential areas outside the tropics, these cockroaches live in basements and sewers and may move outdoors into yards during warm weather. Adult American cockroaches were not able to survive several days at ≤10°C. Under constant temperatures of 8, 9, and 10°C, approximately 40% of cockroaches died within 72 hours.
Relationship with humans
Risk to humans
The odorous secretions produced by American cockroaches can alter the flavor of food. Also, if populations of cockroaches are high, a strong concentration of this odorous secretion can be present. such as Salmonella, on their legs, and later deposit them on foods and cause food poisoning or infection if they walk on the food. House dust containing cockroach feces and body parts can trigger allergic reactions and asthma in certain individuals.
At least 22 species of pathogenic human bacteria, viruses, fungi, and protozoans, as well as five species of helminthic worms, have been isolated from field-collected P. americana (L.)
thumb|right|Underside of P. americana
thumb|P. americana, view from side
Control as pests
thumb|right|Anoplolepis gracilipes ([[yellow crazy ants) moving a dead American cockroach toward their nest in Pohnpei, Micronesia]]
In cold climates, these cockroaches may move indoors, seeking warmer environments and food. Cockroaches may enter houses via wastewater plumbing, underneath doors, or via air ducts or other openings in the walls, windows or foundation. Cockroach populations may be controlled through the use of glue board traps or insecticides. Glue board traps (also called adhesive or sticky traps) are made using adhesive applied to cardboard or similar material. Bait can be placed in the center or a scent may be added to the adhesive. Inexpensive glue board traps are normally placed in warm indoor locations readily accessible to insects but not likely to be encountered by people: underneath refrigerators or freezers, behind trash cans, etc.
Covering any cracks or crevices through which cockroaches may enter, sealing food inside insect-proof containers, and quickly cleaning any spills or messes that have been made is beneficial. Another way to prevent an infestation is to thoroughly check any materials brought inside: cockroaches and their egg cases (ootheca) can be hidden inside or on furniture, or inside boxes, suitcases, grocery bags, etc. Upon finding an egg case, use a napkin to pick it up and then forcefully crush it; the resulting fluid leakage will then indicate the destruction of the eggs inside. Discard the napkin and the destroyed egg case as garbage. || || || 54–215 days<br/>(at )