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COCKROACHES
Cockroaches exist worldwide, with the exception of the polar regions. Cockroaches are also simply known as "roaches".
Among the most well-known species are the American cockroach , Periplaneta americana , which is about 3 cm long, and the German cockroach , Blattella germanica , about 1½ cm long
Biology
Cockroaches are most common in tropical and subtropical climates. Some species are in close association with human dwellings and widely found around garbage or in the kitchen.
Common household roaches
A. German cockroach ,
B. American cockroach ,
C. Australian cockroach ,
D. Oriental cockroach
A female German cockroach carries an egg capsule containing around 40 eggs. She drops the capsule prior to hatching. Development from eggs to adults takes 3-4 months. Cockroaches live up to a year. The female may produce up to eight egg cases in a lifetime; in favorable conditions, it can produce 300-400 offspring. Other species of cockroach, however, can produce an extremely high number of eggs in a lifetime. Laying up to 100 eggs in each egg sac, it only needs to be impregnated once to be able to lay eggs for the rest of its life, allowing one single cockroach to lay over a million eggs during its lifespan.
The cockroach is also one of the hardiest insects on the planet, capable of living for a month without food and remaining alive headless for up to a week. It can also hold its breath for 45 minutes and has the ability to slow down its heart rate.
Cockroaches do indeed have a much higher radiation resistance than vertebrates, with the lethal dose perhaps 6 to 15 times that for humans. However, they are not exceptionally radiation-resistant compared to other insects, such as the fruit fly.
Behavior
New research being conducted shows that cockroaches leave chemical trails in their feces. Other cockroaches will follow these trails to discover sources of food, water, and where other cockroaches are hiding. One of the major implications of this research is a new technique in cockroach pest control. Cockroaches could be potentially removed from a home by leaving a chemical trail that leads away from the home. A study where 50 cockroaches were placed in a dish with three shelters with a capacity for 40 insects in each, the insects arranged themselves in two shelters with 25 insects in each, leaving the third shelter empty. When the capacity of the shelters was increased to more than 50 insects per shelter, all of the cockroaches arranged themselves in one shelter. Researchers found a balance between cooperation and competition exists in group decision-making behavior found in cockroaches. The models used in this research can also explain the group dynamics of other insects and animals.
Cockroaches and health risks
A 2005 national study on factors that affect asthma in inner-city children shows that cockroach allergens appear to worsen asthma symptoms more than other known triggers. This study, funded by the US National Institute of Environmental Health Sciences (NIEHS) and the US National Institute of Allergy and Infectious Diseases (NIAID), is the first large-scale study to rank asthma triggers according to severity.
Cockroach control, with cockroach baits, boric acid, and hydramethylnon gel.
Cockroaches live in a wide range of environments around the world. Pest species of cockroaches adapt readily to a variety of environments, but prefer warm conditions such as found within buildings.
Interesting facts
Most of these insecticides are pyrethroid nerve poisons. The nerve poison induces muscular spasms which often result in the cockroach flipping on its back. Without muscular coordination, the cockroach cannot right itself and eventually dies in its upside-down position.
The lethal dose for the American cockroach is 67,500 rems and for the German cockroach it is between 90,000 and 105,000 rems. In(A "rem" is the dosage of radiation that will cause a specific, measured amount of injury to human tissue). addition, cockroaches can survive on very little; it has been discovered that cockroaches will eat the glue from the back of stamps. |
