Scientists Seek Birth Control For Cockroaches

SAN FRANCISCO, March 28 (Reuters) - The common roach has a lot to be cocky about. Spawning legions of descendants over the span of a lifetime, he is one of the most prolific breeders on the planet. But the male cockroach could well face a new threat: a "safe and effective" method of birth control, developed exclusively for roaches. "Cockroaches - specifically, the brown-banded and the German cockroaches - are the number-one urban household pest in terms of frequency," Cornell University entomologist Jeffrey Scott said in a news release issued for this week's meeting of the American Chemical Society in San Francisco. "They are the target of tons of neurotoxin pesticides every year but they keep coming back for more. What we really need is an effective, nontoxic treatment - a birth-control method - to reduce cockroach populations without bothering other insects or humans, either." Scott and Cornell graduate student Zhimou Wen moved a step in that direction when they cloned five P450 genes from the German cockroach, including one, CYP6L1, which has a definite but thus far mysterious role in the male roach's reproductive testes and accessory glands. "We still don't know what hormone this gene is regulating, but this is enough of a clue to get us started," Scott said. "We're pretty sure the hormone is essential for reproduction. If we can knock out the CYP6L1 protein, we can make the pest struggle to reproduce." Scott said any eventual roach birth control strategy would probably not involve direct genetic tinkering, but rather would seek to identify the relevant hormone or other protein produced by the insect's P450 gene, and then develop chemical inhibitors of that protein for inclusion in roach bait. The result, Scott said, could be a pesticide that afflicts only specific pests and not other insects or animals. But Scott cautioned that much work remained before any kinder, gentler method of roach population control was widely available. "Don't expect roach birth control on your store shelves tomorrow," he said.