Daily News Archive
From August 31, 2001

Researchers say Catnip Oil is More Effective on Mosquitos Than DEET

Scientists Chris Peterson and Joel Coats have determined that nepetalactone, the essential oil in catnip that gives the plant its odor, can be used as a very effective mosquito repellent, according to Iowa State University. In past studies, the researchers had found that catnip oils could repel cockroaches and wondered whether it would have the same effect on mosquitoes. Click here to read the article from University of Iowa.

Peterson said it took about a tenth as much nepetalactone to have the same repellency as DEET. "In other words, nepetalactone is about 10 times more effective than DEET," he said. "Most commercial insect repellents contain about 5 to 25 percent DEET. Presumably, much less catnip oil would be needed to achieve the same repellency as a DEET-based repellent." Why catnip repels mosquitoes remains a mystery. "It might simply be an irritant," said Peterson, "or they just don't like the smell."

DEET, or N,N-diethyl-m-toluamide, has been associated with dermal and neurological reactions in humans. Several cases of toxic encephalopathy (brain disease) associated with the use of DEET on children have been reported in the medical literature. The children exposed to DEET experienced weakness, disorientation, ataxia (loss of coordination) seizures, coma, and in three cases resulted in death. Click here for more information about DEET provided by the Pesticide Management Education Program at Cornell University.

Catnip is a perennial herb in the mint family and grows wild in most parts of the United States. It also is cultivated for commercial use. It's primarily known for its stimulating effect on cats, although some people use the leaves in tea, as a meat tenderizer and as a folk treatment for fevers, colds, cramps and migraines. The plant also is used to make light yellow dye.