August 24, 1999
Catnip Said To Repel Cockroaches
By The Associated Press
NEW ORLEANS (AP) -- The stuff that puts the nip in
catnip is a turnoff for cockroaches.
One form of the chemical in catnip repels cockroaches 100
times better than DEET, the basis for commercial bug
repellents, Iowa State University scientists told a meeting
of the American Chemical Society on Monday.
Chris Peterson and Joel Coats said they began studying
catnip a few years ago when a summer intern told them it
was resistant to insects. The pair boiled catnip leaves and
distilled the active ingredient, a chemical called
nepetalactone.
Peterson also has found roach-repellant compounds in an
inedible softball-sized fruit called the osage orange or
hedgeapple, but doesn't know which specific chemical
creates the roaches' ``yuck' response.
The osage orange is sometimes sold in groceries because
of folk wisdom that putting the fruit in cupboards or
basements will repel just about any bug, they said. The
fruits are filled with a sticky substance that turns rubbery
when exposed to air, they said.
The discovery could lead to new nontoxic methods for
curbing the tenacious insects, which are more than just an
annoyance around the house. The rate of asthma among
children, particularly in cities, is rising. Scientists say the
reason is an allergic reaction to roach excrement.
``We've been chasing cockroach treatments for three
years,' Dr. Peyton Eggleston, a pediatrics professor at
Johns Hopkins University Children's Center, told The
(Baltimore) Sun. ``If you could do it with a repellent, that
would be great.'
The researchers tested repellent power by flooring a cage
with treated and untreated filter paper, and measuring how
much time the roach spends on each side during a
five-minute test.
Although most people would prefer to kill roaches
outright, a repellent might be an effective way to keep them
out of the house after the exterminators have left.
So far, they have only studied the small brown German
cockroaches, rather than their thumb-sized American
cousins. They are just beginning to look at mosquitoes.
Roaches have sense organs on their antennae, feet and
mouths. The ``feelers' seem to be the spot affected by
both catnip and osage oranges, the researchers said.
They have not tested the effectiveness of spreading catnip
leaves around the house. While it might help turn away a
swarm of cockroaches, it could lead to a new infestation --
writhing, blissed-out cats. |
