Insect exhibits are found in the Washington DC National Zoo. Out of the many insects on display, I made observations on cockroaches. My focus was on the Haitian cockroach (Blaberus Discoidalis), 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 lightning 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 cockroaches hide within small cracks and crevices. This behavior 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 they finish eating, the insects go back to their concealment. Although they come out during the day to eat, most roaches prefer feeding in the dark and can be startled by a sudden flash of light. The insect is omnivorous, consuming almost any dead matter whether plant or animal-derived. The following ecdysis; the periodical shedding of the 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 solitude. The roaches also have a tendency to gnaw plastic and leather casings, furniture and paper materials resulting in extensive damages (Bell, Louis & Christine, p. 10).
Aside from the damage caused by eating these materials, the cockroaches 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 taken care of by the mother until they gain independence. 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 is not dependent on their multiplication rate, but rather their ability to resist adverse conditions and scarcity of their enemies such as ants (Bell, Louis & Christine, p. 11).
Morphologically, the cockroach body is oval shaped and flattened. The head is covered with a large pronotum and ventrally located mouth parts. The head’s pericranium is made of layers of chitinous material on which hinges the movable labrum. The insect has a sensitive, highly segmented antenna that usually faces backward 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 with 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 an 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 an oily substance with a characteristic order believed to be a predator repellent (Bell, Louis & Christine, p. 4).
Works Cited
Bell, William, Louis Roth & Christine Nalepa. Cockroaches: Ecology, Behavior, and Natural History. Baltimore: Johns Hopkins University Press, 2007. Print.