The hardy cockroach, which has survived flood, fire and all forms of assault for millions of years, may be about to come to grief. And the key to its possible downfall is as old as the bug itself: sex. A Kansas scientist has developed a sex-odor cockroach trap that lures male cockroaches into making a 25-foot dash to their doom. The trap, baited with a synthetic sex pheromone that duplicates the odor secreted by the female, draws the males onto sticky paper traps where they are poisoned. "With only a whiff of the pheromone, healthy male cockroaches have been known to cover a distance of 25 feet in 5 seconds to jump into a pheromone-laden trap," said the inventor, Dr. William Bell, professor of entomology at the University of Kansas. Cockroaches, said by scientists to be one of the oldest life forms on earth, are also among the most prolific. The female roach produces about 16 offspring every five days. Details of Bell's invention were released by the National Science Foundation. Bell said he expected some private company would soon pick up his invention which he called "highly effective." "I'm not sure which company will transfer the technology to the public but it's going to happen," he said.