In the Washington D.C National Zoo, are insect exhibits. Out of the many insects on display, I made observations on cockroaches. My focus was on the Haitian cockroach (BlaberusDiscoidalis), a species from Central America. In this paper; I will describe the roaches with reference to behaviors, habitat and morphology.
Cockroaches are crawling insects that can move with lightening speed especially on sensing predators. Their behavioral patterns are characterized by a tendency to inhabit warm places away from the light. In most instances, the roaches hide within small cracks and crevices, a behavior that is complemented well by their thin, flattened bodies. They also inhabit swamps, tropical forests, caves and grasslands. They rarely make any movements unless when crawling towards edibles. After finishing eating, the insect goes back to its concealment. Although, they come out during the day to eat, most roaches prefer feeding in the dark and can be startled by sudden flash of light. The insect is omnivorous, consuming almost any dead matter whether plant or animal derived. Following ecdysis; the periodical shedding of outer skin, the roaches can eat that cast skin as well as egg cases. The different species attack one another and they may exist in colonies or in solitude. The roaches also have a tendency to gnaw plastic and leather casings, furniture and paper materials resulting in extensive damages (Bell, Louis &Christine, pg. 10).
Aside from the damage caused by eating away these materials, the roaches also soil their habitats leaving a nauseous and persistent odor and taints from their droppings. The roach has a predatory instinct and preys on bedbugs. During oviposition, they display an atypical habit whereby eggs are enclosed within an oval elongate capsule that develops in the abdomen and is discharged when the eggs enclosed are ready to hatch. On hatching, the young are brooded by the mother until they can fend on their own. They take long to mature, occasionally passing through various molting stages. The insect hibernates in cold weather only reproducing during the warm seasons. Their existence does not depend on the rate at which they multiply but rather their ability to resist adverse conditions and scarcity of their enemies such as ants (Bell, Louis &Christine, pg. 11).
Morphologically, the cockroach body is oval shaped and flattened. The head is covered by a large pronotum and with ventrally located mouth parts. The head’s epicranium is made of layers of chitinous material on which hinges the movable labrum. The insect has a sensitive, highly segmented antenna that usually faces backwards when the insect is resting but perpendicularly when feeding or moving. The roach has two sets of wings with the forewings leathery in texture while the long hind wings are relatively delicate. The membranous hind wings are used for flying. The roach has a rich reddish brown color and the body is covered by a brittle exoskeleton made of chitin. The body has three major segments; head, thorax and abdomen. The head and thorax are connected by a flexible tube made of articular membrane.The thorax is compartmentalized into three segments, anterior, middle and posterior metathoraxes. The abdomen of the roach has ten distinct segments with each segment constituting a ventral sternum and a dorsally placed tergum. On the abdominal sides are spiracles and stick glands that produce oily substance with a characteristic order believed to be a predator repellent(Bell, Louis &Christine, pg. 4)