The American cockroach (Periplaneta americana), also known as the waterbug, or misidentified as the palmetto bug (see Florida woods cockroach for the differences), is the largest species of common cockroach, and often considered a pest. None of the Periplaneta species are endemic to the Americas; despite the name, P. americana was introduced to the United States from Africa as early as 1625. They are now common in tropical climates because human activity has extended the insect's range of habitation, and global shipping has transported the insects to world ports including the Southern United States, Tenerife, southern Spain, Greece, Taiwan, and Cape Town and Durban, South Africa and the United Kingdom.
American cockroach adults grow to an average length of around 4 centimetres (1.6 in) and about 7 millimetres (0.28 in) tall. They are reddish brown and have a yellowish margin on the body region behind the head. Immature cockroaches resemble adults except that they are wingless.
The insect can travel quickly, often darting out of sight when someone enters a room, 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 carried out at the University of California, Berkeley in 1991, a Periplaneta americana registered a record speed of 5.4 kilometres per hour (3.4 mph), about 50 body lengths per second, which would be comparable to a human running at 330 kilometres per hour (210 mph).
It has a pair of large compound eyes each having over 2000 individual lenses, and is a very active night insect that shuns light.
Risk to humansEdit
Many people find cockroaches disgusting and terrifying. While cockroaches do not typically bite and are not poisonous, they can pick up disease-causing organisms which after growing and multiplying in their guts can subsequently be deposited on kitchen surface areas, utensils, and food items. In addition, "cockroaches can pick up disease-causing bacteria like Salmonella on their legs and later deposit them on foods and cause food poisoning". House dust containing cockroach feces and body parts can trigger allergic reactions and asthma in certain individuals.
American cockroaches generally live in moist areas, but can survive in dry areas if they have access to water. They prefer warm temperatures around 29 °C (84 °F) and do not tolerate cold temperatures. In residential areas, these cockroaches live in basements and sewers, and may move outdoors into yards during warm weather. These cockroaches are common in basements, crawl spaces, cracks and crevices of porches, foundations, and walkways adjacent to buildings.
The American cockroach is a scavenger that feeds on decaying organic matter and a variety of other foods. It is particularly fond of fermenting foods.
Females produce an egg case called an ootheca which protrudes from the tip of the abdomen. After about two days, the egg cases are placed on a surface in a safe location. Egg cases are about 0.9 centimetres (0.35 in) long, brown, and purse shaped. Immature cockroaches emerge from egg cases in 6 to 8 weeks and require 6 to 12 months to mature. Adult cockroaches can live up to one year, during which females produce an average of 150 young.
Due to their large size and slow development, large infestations of these insects are not common within houses. However, during certain times of the year, these cockroaches may move inside a house from outside. In cold weather these cockroaches may move indoors, seeking warmer temperatures and food. Cockroaches may enter houses through sewer connections, under doors, around plumbing, air ducts, or other openings in the foundation. Cockroach populations may be controlled through the use of insecticides.