This is my lead section

History

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Cockroaches date back all the way to the Carboniferous Period. The cockroach's form evolved directly from the segmented form and simple anatomy of the onychophoran, a very functional and successful pattern. Cockroaches are thought to have emerged on Pangaea, the original super-continent, or on Gondwanaland, the daughter continent of Pangaea. The cockroach made many adaptations over millions of years to be able to survive the major die offs that many species succumbed to. [1]

Characteristics

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The standard cockroach is made of three sections that consist of a body that is flattened and broadly oval, with a shield-like pronotum covering its head. A pronotum is a plate-like structure that covers all or part of the dorsal surface of the thorax of certain insects. They also have chewing mouth parts, long, segmented antennae, and leathery fore wings with delicate hind wings. The third section of the cockroach is the abdomen. [2]

Body Functions

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Everyone knows that the brain is one of the most important organs in the body of any creature, but this is not the case with cockroaches. A cockroach is able to live an entire week without a head. The reason for this is because most of the nervous system functions are carried out in the nerve ganglia which is found throughout the cockroach’s body. The function of breathing is also unaffected because a cockroach does not breathe through its mouth; instead a cockroach brings air into its body through holes in its side called spiracles. The air will then travel through tubes into its body called tracheae, feeding the organs and tissues with oxygen. The abdomen of a cockroach consists of a tube-like heart that moves the blood to the organs and tissues. Even though a cockroach has an aorta, most of the blood travels through a network of spaces called a hemocoel. Fat is also stored differently in a roach than in a human. A cockroach stores its fat in one centralized location called the fat body, instead of being spread through its entire body. The digestive system of a cockroach is also located in its abdomen and resembles a simplified version of a mammal’s digestive system. The alterations that are in the cockroach’s digestive system allow it to eat cellulose and other tough materials. One adaptation is a crop that is able to hold food until a toothy section of the digestive tract, called the proventriculus, can pulverize it. Sacs called the gastric cacea hold enzymes and microbes that continue to digest the food. These sacs are useful when the roach consumes wood or cellulose because the roach is only able to absorb the nutrients after further digestion. Cockroaches do have compound eyes, even though they are not as prominent as other insects, which are made of photoreceptor cells called ommatidia. A hard ring called the ocular sclerite surrounds the photoreceptors. Cockroaches use their long antennae to fell and smell. Their antennas are made up of tiny hair-covered segments. “An experiment conducted by Makota Mizunami and Hidehiro Watanabe of Tohoku University took advantage of the cockroaches’ obsession with sugar to test their sense of smell via their antenna and to observe their responses.” Through this experiment, they were able to conclude that the cockroaches’ tiny brains were able to remember and associate, through the sense of smell and respond by salivating. Cockroaches also have three different sets of legs which all serve a different purpose. The prothoracic legs, which are the legs that are closest to the cockroach’s head, act like brakes when it runs. The next set of legs, the mesothoracic legs, is the ones that move back and forth to either speed up the roach or slow it down. Lastly, the metathoracic legs are the back legs which also help the cockroach move forward. These are the legs that give the cockroach its extra speed. When this set of legs is in use, the cockroach is able to move about fifty body lengths in a second. Even though each leg has a different function and different lengths, they all have the same make up. The upper portion of the leg that attaches to the thorax is called the coxa. The trochanter acts like a knee to let the roach bend its leg, the femur and tibia resemble the thigh and shin bones of a human and the segmented tarsus functions like an ankle and foot. The front and back leg move at the same time, along with the middle leg on the opposite side. This makes it to where the cockroach is able to move over nearly any terrain. Although cockroaches have very limited eyesight, they are extremely sensitive to changes and movements in light. They are also very sensitive sound waves. Both light and sound are detected are detected through sensory hairs located at their tail which is on the lower part of their abdomen. A cockroach is so sensitive to movement that it is able to detect a movement that is less than a millionth of a millimeter.[3]

Life Cycle

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American cockroaches have three developmental stages: egg, nymph, and adult.[4]

Risk to Humans

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The American cockroach produces odorous secretions that can alter the flavor of food. Also if there is a high concentration of cockroaches, there will be a strong concentration of this odorous secretion.[4]

Diet

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American cockroaches feed upon a great variety of materials such as cheese, beer, leather, bakery products, starch in bookbindings, manuscripts, glue, hair, flakes of dried skin, dead animals, plant materials, soiled clothing, and glossy paper with starch sizing.[4]

Control

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It is also wise to cover any cracks or crevices that the cockroaches may enter in through. Also, always clean any spills or messes that have been made so that the cockroaches will not be attracted to the food source. Another way to prevent an infestation of cockroaches is to thoroughly check any material that is brought inside. Cockroaches and egg cases can be hidden inside or on furniture, in boxes, suitcases, grocery bags etc.[4]

References

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  1. ^ Copeland, Marion (2003). Cockroach. London: Reaktion Books LTD. ISBN 186189192. {{cite book}}: Check |isbn= value: length (help)
  2. ^ Bell, William (2007). Cockroaches. Baltimore: The Johns Hopkins University Press.
  3. ^ Wilson, Tracy. "How Cockroaches work". how stuff works. Retrieved 22 October 2012.
  4. ^ a b c d Jacobs, Steve. "American Cockroaches". The Pennsylvania State University. Retrieved 18 October 2012.