CHICAGO, Aug 28 (Reuters) - Catnip, which mysteriously creates euphoria in cats, is an effective insect repellent, according to Iowa State University scientists.

In a paper presented to the American Chemical Society meeting in Chicago this week, entomologists Chris Peterson and Joel Coats said they have sought a patent for the use of the catnip oil nepetalactone as a repellent for bothersome pests such as mosquitoes and cockroaches.

Nepetalactone, which gives catnip its odor, was found to be 10 times more effective than the popular insect repellent diethyl-meta-toluamide (DEET). In experiments at their Ames, Iowa, laboratory, the scientists found a greater percentage of mosquitoes were repelled by the catnip extract than by DEET.

"It might simply be an irritant, or they just don't like the smell," Peterson said in a statement. Nepetalactone also repelled a common type of cockroach and so might hold potential for the home pesticide market.

An herbal plant in the mint family that is grown commercially as well as in the wild, catnip's stimulating effect on cats is unexplained. Some people use the leaves in tea, as a folk treatment for fevers, colds, cramps and migraines, as a meat tenderizer and to make a yellow dye.

Peterson said because of its capability in repelling insects, less of the catnip oil would have to be used in any potential repellent product. DEET is a chemical that some users find causes rashes, swelling and eye irritation.

12:15 08-28-01