CATNIP might work as a mosquito repellent, but will it draw cats instead?

Monday, August 27th 2001, 12:00 am
By: News On 6

CHICAGO (AP) _ Catnip, the stuff that drives cats wild, also appears to drive mosquitoes away, research suggests.

Laboratory experiments at Iowa State University suggest that the oil in the catnip plant is about 10 times more effective at repelling mosquitoes than DEET, the chemical in many commercial insect repellents.

The research is preliminary and catnip has yet to be tested on humans as a mosquito repellent.

The bigger question _ especially for feline-haters _ might be whether such a repellent would turn humans into walking cat magnets.

Not necessarily, said Joel Coats, chairman of entomology at Iowa State.

Catnip would probably work only at short-range, like DEET, he said. ``If you sat near a cat, you might generate more interest than usual. They might want to play,'' he said. But ``in terms of walking down the street,'' there would be no effect.

A report on the research was on Monday's agenda at the American Chemical Society's meeting in Chicago.

Ulrich Bernier, a U.S. Agriculture Department chemist who studies mosquitoes, said that while DEET is generally safe, some people prefer natural alternatives. But he said just because catnip worked better in the lab does not mean the same thing would happen if the oil were put on human skin.

Catnip is a mint-related plant that grows wild in much of the United States. It is used in pet toys and in teas, so it is unlikely that it would be harmful to humans if used in repellent sprays or creams, Coats said.

Coats and entomologist Chris Peterson put mosquitoes in a 2-foot glass tube. Half the tube was treated with substances in catnip oil that give the plant its pungent, minty aroma _ two forms of the compound nepetalactone. After 10 minutes, an average of 80 percent of the mosquitoes had moved to the untreated side of the tube.

Similar tests were done with DEET, but it took about one-tenth as much nepetalactone as DEET to have the same effect, Peterson said.

Iowa State has submitted a patent application for the use of catnip compounds as insect repellents.

The scientists previously found that catnip is also effective at repelling cockroaches.