Subject: No more DEET?
Date: Sep 11 00:31:21 1999
From: Bob Mauritsen - bluetooth at csi.com


I don't know how many on Tweeters read Science News, but
for those who don't, the following article (SN, V156, Sept 4, 1999)
might engender some tentative hopefulness. The relevant part
is at the end.

Bob Mauritsen


Roaches Don't Go Crazy Over Catnip

A feline friend may go into ecstasy over a whiff of catnip, but
the same odor will send a cockroach skittering away, according to
entomologists at Iowa State University in Ames. Their finding may
lead to new roach repellents based on an active compound found in
the catnip herb, Nepeta cataria.

Chris J. Peterson and Joel R. Coats tested the reaction of German
cockroaches to two forms of nepetalactone, the herbal compound that
drives cats wild. The researchers gave insects a choice of walking
on either a piece of paper treated with nepetalactone or untreated
paper. For driving away roaches, one form of the compound was 100
times as effective as deet, an ingredient found in commercial insect
repellents. Removing roaches' antennas rendered them indifferent
to nepetalactone, revealing that receptors on those structures,
rather than on their feet or mouthparts, respond to the compound.

The researchers are now testing nepetalactone's effect on mosquitoes.
An insect repellent based on catnip could be safe to use on people and
have a more pleasant smell than the ones currently on the market
do. The only obvious drawback, they note, is that although such a
product would keep insects at bay, it might draw unwanted attention
from cats.