American cockroach

Appearance

Of all common cockroach species, the American cockroach has the largest body size; molts 6–14 times before metamorphosis; and has the longest lifecycle, up to about 700 days.

It has an average length around 4 cm and is about 7 mm tall. They are reddish brown and have a yellowish margin on the pronotum, the body region behind the head. Immature cockroaches resemble adults except they are wingless.

The cockroach is divided in 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 5.4 km/h , about 50 body lengths per second, which would be comparable to a human running at 330 km/h .

It has a pair of large compound eyes, each having over 2000 individual lenses , and is a very active night insect that shuns light.

American cockroach nymphs are capable of limb regeneration.The American cockroach shows a characteristic insect morphology with its body bearing divisions as head, trunk, and abdomen. The trunk, or thorax, is divisible into prothorax, mesothorax and metathorax. Each thoracic segment gives rise to a pair of walking appendages . The organism bears two pairs of wings. The fore wings, known as tegmina, arise from mesothorax, and are dark and opaque. The hind wings arise from the metathorax and are used in flight, though cockroaches rarely resort to flight. The abdomen is divisible into 10 segments, each of which is surrounded by chitinous exoskeleton plates called sclerites, including dorsal tergites, ventral sternites, and lateral pleurites.

Distribution

Despite the name, none of the ''Periplaneta'' species is endemic to the Americas; ''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 insects' range of habitation, and are virtually cosmopolitan in distribution as a result of global commerce. American cockroaches are also known as plagues in the warm Mediterranean coast of Spain, as well as in southern Spain and southern Portugal and in the Canary Islands, where the winters are mild/warm and frost-free, and the summers are hot.

Habitat

American cockroaches generally live in moist areas, but can survive in dry areas if they have access to water. They prefer high temperatures around 29 °C 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.

Food

American cockroaches are omnivorous and opportunistic feeders that eat materials such as cheese, 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 are particularly fond of fermenting foods. They have also been observed to feed upon dead or wounded cockroaches of their own or other species.

Evolution

Cockroaches date back to the Carboniferous period. They are thought to have emerged on the supercontinent Pangaea, or on Gondwana, the daughter continent of Pangaea. The cockroach made many adaptations over the years to be able to survive the major die-offs to which many species succumbed. However, like all the extant species, the American cockroach has probably evolved in the last few millions to thousands of years and is a fully modern organism.