An Even Better Use for Catnip - Repelling Roaches
August 25, 1999 - 0:0
WASHINGTON The stuff that makes catnip irresistible to cats makes it odious to cockroaches, researchers said. They said they found that two old home remedies for getting rid of bugs -- catnip and hedgeapple -- really did work and said they might serve as the basis for insect repellents. Chris Peterson and Joel Coats of Iowa State University were checking out old folk tales about hedgeapple, also known as osage orange, and catnip.
"There are really no commercial cockroach repellents," Peterson said. "Most are insecticides designed to kill roaches. People just don't seem to want them to go away -- they want them dead." Peterson and Coats told a meeting of the American Chemical Society in New Orleans that the active ingredient in catnip is Nepetalactone. It is the chemical that sends many cats into paroxysms of joy when they encounter the herb.
"The two forms of nepetalactone had different repellent activity to the cockroaches," they wrote in a statement ahead of their presentation. But it was stronger that deet, a synthetic compound used in many commercial insect repellents. "One form of nepetalactone was 100 times more potent than deet," they said. Cockroaches were given the choice of walking on treated or untreated paper.
They stayed away from the treated paper, which suggests the chemical repelled them, Coats and Peterson said. They tested hedgeapples in a similar way. Hedgeapples -- hard, inedible softball-sized fruit -- are often sold in grocery stores as insect repellents. "It is said that placing these fruits in cupboards or basements will repel cockroaches, spiders, mice, flies, crickets or just about anything people care to repel," Coats and Peterson said.
Careful observation showed that bugs rarely eat them in the wild, they added. They boiled the fruit and spread the resulting compound on a piece of paper. Cockroaches avoided the treated paper. "So far nobody really knows why insect repellents work," the researchers said. But when the insects had their antennae removed, they did not seem to avoid either compound. Peterson and Coats used the small, German cockroaches common in many parts of the United States but said they thought other cockroaches would respond in the same way.
(Reuter)
"There are really no commercial cockroach repellents," Peterson said. "Most are insecticides designed to kill roaches. People just don't seem to want them to go away -- they want them dead." Peterson and Coats told a meeting of the American Chemical Society in New Orleans that the active ingredient in catnip is Nepetalactone. It is the chemical that sends many cats into paroxysms of joy when they encounter the herb.
"The two forms of nepetalactone had different repellent activity to the cockroaches," they wrote in a statement ahead of their presentation. But it was stronger that deet, a synthetic compound used in many commercial insect repellents. "One form of nepetalactone was 100 times more potent than deet," they said. Cockroaches were given the choice of walking on treated or untreated paper.
They stayed away from the treated paper, which suggests the chemical repelled them, Coats and Peterson said. They tested hedgeapples in a similar way. Hedgeapples -- hard, inedible softball-sized fruit -- are often sold in grocery stores as insect repellents. "It is said that placing these fruits in cupboards or basements will repel cockroaches, spiders, mice, flies, crickets or just about anything people care to repel," Coats and Peterson said.
Careful observation showed that bugs rarely eat them in the wild, they added. They boiled the fruit and spread the resulting compound on a piece of paper. Cockroaches avoided the treated paper. "So far nobody really knows why insect repellents work," the researchers said. But when the insects had their antennae removed, they did not seem to avoid either compound. Peterson and Coats used the small, German cockroaches common in many parts of the United States but said they thought other cockroaches would respond in the same way.
(Reuter)