Cockroaches are commonly found pests in our home. There are 4600 total species of cockroaches worldwide of which 30 associated with human habitat.About four species are well-known pests.
Cockroaches have broad, flat bodies and relatively small heads. They are generalised pests, with few only modifications, and may be among the most straightforward living nocturnal insects. The mouthparts are underneath of the head and include generalised chewing mandibles. They have big compound eyes, two ocelli, and long, adjustable antennae.
They comprise of two pairs of wings, the first couple (the tegmina) are strict and protective, lying as a protection on top of the second pair. The legs are high, with large coxae and five claws each. The middle has ten segments and several cerci.
These are the insects of the order Blattodea sometimes called Blattaria.
Some of the best-known cockroaches are
The American cockroach (Periplaneta Americana) about 30 mm (1.2 in) in length;
The German cockroach (Blattellagermanica) about 15 mm (0.59 in) in length;
The Asian cockroach (Blattella Asahi Nai) also about 15 mm (0.59 in) in height;
The Oriental cockroach, Blatta Orientalis, about 25 mm (0.98 in).
Cockroaches live in a variety of environments around the world. Pest species adapt readily to a variety of situations but prefer warm conditions found within buildings. Many tropical species prefer even more temperate climates.
Cockroaches are mainly night-loving and will run away when exposed to light.
Cockroaches leave chemical traces in their faeces, as well as emitting airborne pheromones for mating and swarming. These chemical traces transmit bacteria onto the area. Others will follow these paths to discover sources of water and food, and also find where other cockroaches are living. Thus, cockroaches can exhibit rising behaviour, in which group or swarm behaviour arises from a simple set of individual cooperation.
Female cockroaches are seldom seen carrying egg cases on the end of their body; the eggs case called an ootheca. The egg case may take more than five hours to lay and is bright white. The eggs hatched from the mixed pressure of the hatchlings gulping air. The hatchlings are bright white nymphs in the beginning and continue inflating themselves with air, becoming harder and darker within about four hours. They’re transient white stage while hatching and later while moulting has led many to claim the existence of albino cockroaches.