Get Rid Of Cockroaches?

By Unmesh Kher

Not likely. we've deployed everything from sex hormones to roach-killing wasps in our billion-dollar war against the cockroach, and we haven't made much of a dent. Over the past decade, better bait and smarter tactics have knocked the roach from first to third on the household-pest hit parade (after ants and termites), but there are still a lot more of them than us.

The problem is that after 350 million years of evolution, your kitchen-variety cockroach is exquisitely designed for survival. A single female German cockroach (the most prolific of the seven major pest species) generates 35,000 descendants a year on a diet of just about anything: table scraps, toothpaste, glue, hair--even, in a pinch, her young. Such fecundity has evolutionary benefits. The more offspring she produces, the better the chance that one of them will be born resistant to whatever poisons future scientists decide to spray. Today's best roach bait is almost universally fatal, but it's only a matter of time before a bug that's immune scuttles out from underneath someone's fridge.

Even if we did manage--against all odds--to rid a city of roaches, they would still do just fine. What the species really has going for it is wanderlust--and a penchant for traveling with people. That is how cockroaches first colonized the world, and that's how they're spreading today, hitchhiking on trains, planes, automobiles--even up the trousers of unknowing tourists. In Taiwan, for example, where it would have been a curiosity only 30 years ago, the German cockroach is happily entrenched. "The last living thing on the planet," says entomologist Roger Gold of Texas A&M University, "will be a roach eating a lichen on a rock."

--By Unmesh Kher