The oriental cockroach (also known as: waterbug and Blatta orientalis) is a large species of cockroach, measuring about 1 in (2.5 cm) in length at maturity. It is dark brown to black in colour and has a glossy body. The female Oriental cockroach has a somewhat different appearance to the male, appearing to be wingless at casual glance but has two very short and useless wings just below her head. She has a wider body than the male. The male has long wings, which cover a majority of his body and are brown in colour, and has a more narrow body. The odd male is capable of very short flights, ranging about 2 to 3 meters. The female oriental cockroach looks somewhat similar to the Florida woods cockroach, and may be mistaken for it.
In order to thrive, cockroaches need a place to hide. They prefer warm places and a relatively high humidity if possible; they also need a source of food/liquid. The optimum temperature for oriental cockroaches is between 20 °C (68 °F) to 29 °C (84 °F). Female oriental cockroaches have vestigial tegmina (reduced forewings) and males have longer tegmina. Cockroaches are mainly nocturnal. Oriental cockroaches can be elusive in that a casual inspection of an infested dwelling during the day may show no signs of roach activity.
The German cockroach (Blattella germanica) 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.
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 entrances.
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.
Brown-banded cockroaches get their name from the two lighter bands they have across their dark brownish bodies. In addition to the distinctive banding, males have full wings, which reach beyond the tip of their rather pointed abdomens, but females have underdeveloped wings, much shorter than their broad, rounded abdomens. The lighter band markings are much more distinct in nymphs than in adults of either sex. They grow to 5/8 inch long.
Male brown-banded cockroaches have been observed to fly indoors. Among cockroach species, brown-banded cockroaches have the most distinctions between sexes. Females have larger abdomen and shorter wings than males. Brown-banded cockroaches often hide their egg cases in or under furniture.
Within a room, these roaches tend to prefer warmer, drier, and higher locations than do any of the other urban pest roaches. They are often found in upper cabinets or in other rooms than the kitchens (food preparation areas) or bathrooms.
Cockroaches have been reported to spread at least 33 kinds of bacteria, six kinds of parasitic worms, and at least seven other kinds of human pathogens. They can pick up germs on the spines of their legs and bodies as they crawl through decaying matter or sewage and then carry these into food or onto food surfaces. Germs that cockroaches eat from decaying matter or sewage are protected while in their bodies and may remain infective for several weeks longer than if they had been exposed to cleaning agents, rinse water, or just sunlight and air. Recent medical studies have shown that cockroach allergens cause lots of allergic reactions in inner city children. They were even shown to cause asthma in children. These allergens build up in deposits of droppings, secretions, cast skins, and dead bodies of roaches.