Some common garden plants could be the answer to warding off the West Nile virus. Researchers at Iowa State University found oil from catnip to be a successful repellent to the mosquitoes that caused yellow fever, and new research shows it also works against the biting insects that spread the West Nile Virus. Iowa State entomologist Joel Coats has been studying the catnip oil and says it could provide an alternative to DEET, the most common chemical used in commercial repellents. He says the safety record has been good, but regulatory agencies have been encouraging the use of lower does, especially on children.Coats says it appears the catnip repellent lasts about two hours, less than what DEET offers. He says it would be a rare alternative. He says there are a few other natural repellents on the market with limited success, mostly plant oils like the catnip. The I-S-U Research Foundation owns the rights to the catnip research and is seeking to acquire approval to sell the catnip repellent.He says the E-P-A approval process takes about a year to complete. If you’re thinking that planting catnip around your home might help, think again. He says most of the oil is “locked into” the leaves and stalk of the plant, so he says it wouldn’t do much good simply as a plant. Plus, Coats warns that pure catnip oil is too strong to put directly on skin. Catnip may not be the only plant to help repel mosquitoes and West Nile. Coats says they’re looking into the use of hedge apples too. He says they’re examining the chemicals in the hedge apples and are finding some good potent possibilities. He says the hedge apple repellents will still require a lot of research.