German Roach

The German cockroach, Croton bug or Steam fly is a small species of cockroach, measuring about 1.3 cm (0.51 in) to 1.6 cm (0.63 in) long; however, they are known to get bigger. It can be tan through brown to almost black, and has two dark parallel streaks running from the head to the base of the wings. Although it has wings, it is unable to sustain flight. The German cockroach is one of the most common and prominent household cockroaches in the world, and can be found throughout many human settlements. These insects are particularly associated with restaurants, food processing facilities, hotels, and nursing homes. In colder climates, they are found only near human habitats, since they are not very tolerant to cold. However German cockroaches have been found as far north as Alert, Nunavut. The German cockroach is originally from Asia, it is very closely related to the Asian cockroach, and to the casual observer they appear nearly identical and may be mistaken for the other. This cockroach can be seen in the day occasionally, especially if there is a large population or if they have been disturbed. However, sightings are most commonly reported in the evening hours as they are most active at night. This type of cockroach can emit an unpleasant odor when excited or frightened.

The German cockroach is very successful at establishing an ecological niche in buildings, and is very hardy and resilient against attempts at pest control. This is because of the large number of nymphs produced from each egg case, the short period between birth and sexual maturity, and their ability to easily hide due to their small size. The mother also carries the egg case (called an ootheca) with her during the germination period, rather than depositing it like other species, a practice which would leave them vulnerable in a human habitat to zealous attempts to wipe them out. This cockroach is also smaller than many other species so it can more easily hide and fit into very small cracks and crevices to evade humans. That is also the main reason they can most effectively be controlled with bait in cracks and crevices near harbor-ages. These type of pest control methods should kill 95% of the overall population in a property due to their fast reproductive cycles. The German cockroach, discounting the presence of pets, has few natural predators inside a human habitat. The German cockroach's thigmotactic nature compounds the difficulty of pest control treatment. The immature cockroaches will live off excretions and moults from the adult cockroaches and thus can remain hidden away from most surface treatments.

The German cockroach is omnivorous and a scavenger. They particularly like starch, sugary foods, grease and meats. In certain situations where there is a shortage of foodstuffs, they may eat household items such as soap, glue and toothpaste or they may even turn cannibalistic, often chewing on the wings and legs of each other.

Asian Roach

Blattella asahinai, the Asian cockroach is a species of cockroach that was first described in 1981 from insects collected on Okinawa Island, Japan. It is nearly identical to the German cockroach except for a few minor morphological differences. Like the German cockroach, it is about 1.6 cm (0.63 in) long, is tan to brown in color, and has wings. However, its wings are longer than the German cockroach, and there is a difference between a groove in the abdomen between the two species. There are other differences. The quickest way to tell the difference between the two species is that the Asian cockroach is a strong flier (almost like a moth) and is attracted to light, unlike the German cockroach. This outgoing species tends to prefer the outdoors, whereas the depressive German cockroach prefers living indoors.

It is found in tropical and subtropical climates, and was first identified in the United States in 1986 in Lakeland, Florida. It has since expanded throughout much of Florida and is spreading into other southern states. Its population reaches it zenith in late August and declines rapidly with the onset of cool weather. During adverse weather conditions such as cold weather or dry conditions the Asian cockroach will burrow down into the leaf litter.


American Roach

The American cockroach, also known as the palmetto bug or waterbug. particularly in the southern United States, is the largest species of common cockroach, and often considered a pest. None of the species are endemic to the Americas; despite the name, were 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.

American cockroach adults grow to an average length of around 4 centimeters (1.6 in) and about 7 millimeters (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 American Roach registered a record speed of 3.4 mph, about 50 body lengths per second, which would be comparable to a human running at 210 mph.

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

American cockroaches generally live in moist areas, but can survive in dry areas if they have access to water. They prefer warm temperatures around 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 centimeters (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.

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.