Cockroaches
Have you ever tried to get rid of cockroaches? Those stupid little bugs refuse to go. You can chase them, starve them, spray them, and even try to squash them. But no matter what you do, they always come back. I have read that they are the only creatures that can survive a nuclear explosion. How have cockroaches survived in such extreme conditions? What has enabled them to be such resilient insects? The answer is simple. Cockroaches have survived in some of the Earth’s most hostile environments because they possess several unique physical features, an amazing reproductive process, and an immune system that has frustrated even the best efforts of exterminators to get rid of them.
Cockroaches are thin, torpedo-shaped insects. Their body shape allows them to squeeze into small cracks or holes in walls and ceilings or dart into drains, thus avoiding many dangers. Their outer shell is unusually hard, making them almost impossible to crush. Cockroaches have sticky pads on their claws that enable them to climb walls or crawl upside down on ceilings. They also have two little tails, called “cerci,” to alert them to danger. These cerci are covered with tiny hairs that, like antennae, are sensitive to things as small as a speck of dust or as seemingly innocent as a puff of air. Finally, if cockroaches cannot find food, they can sustain themselves for up to a month without food, as long as they have water. Combined with their other physical features, this ability to go without food for long periods has made the cockroach almost invincible.
Cockroaches give credence to the old adage that there is safety in numbers. They reproduce at a truly amazing rate. About two months after mating, a new generation of cockroaches is born. One cockroach can produce about two dozen offspring each time it mates. To get some idea of the process behind their reproductive power, imagine that you start with three pairs of cockroaches. Approximately three weeks after mating the females lay their eggs, which hatch some forty-five days later. If we assume two dozen eggs from each female, the first generation would number seventy-two. These cockroaches would continue to multiply geometrically so that by year’s end the colony would total more than 10,000 cockroaches. Stopping this process is almost impossible because, even if we were successful in annihilating the adult population, it is more than likely that a new generation would already be on the verge of hatching.
Finally, cockroaches have frustrated scientists with their ability to immunize themselves against drugs, poisons, and bomb gases. Cockroaches then pass this new immunity on to the next generation quicker than a new insecticide can be developed. Although scientists have studied the cockroach for decades, they have not yet discovered the biological mechanism that enables them to develop immunity so rapidly. It is not surprising that many scientists are now focusing on a “birth control” solution for cockroaches. By rendering at least some portion of the adult population sterile, scientists hope to gain a measure of control over these pesky insects.
Today there are approximately 3,500 different species of cockroaches. They have survived on this planet since the time of the dinosaurs some 350 million years ago. Whether or not scientists are successful in their latest efforts to rid us of cockroaches is yet to be determined. Odds are that they will not succeed. Given the cockroach’s amazing record of survivability, it is not likely to turn up on anyone’s list of endangered species.
—Courtney Smith