Insecticides Are Sugar-Coated For Real
By Judy McBride
March 10, 2000
insecticides--an oxymoron? Not these sugar esters tested by
Agricultural Research Service and
university entomologists around the country.
They're lethal to mites and soft-bodied insects--whiteflies, aphids, thrips
and pear psylla--almost instantly after contact. Then Mother Nature takes over,
degrading the esters into harmless sugars and fatty acids. And they do little
harm to insect predators and are completely nontoxic to animals and people. In
fact, some are approved as food-grade safe.
AVA Chemical Ventures of Portsmouth, N.H., and ARS recently applied for a
patent on the sugar esters. AVA hopes to have the first of these compounds on
the market by the end of this year, pending registration with the
U.S. Environmental Protection Agency.
The sugar esters can kill up to 100 percent of the soft-bodied insects and
mites they contact. And insects are not expected to develop resistance any time
soon because of the way the esters work, according to ARS entomologist Gary
Puterka at the agency's Appalachian Fruit Research Station in Kearneysville, W.
Va. Puterka coordinated the studies nationwide and is co-inventor on the new
Throughout four years of tests, the sugar esters have been more--or
as--effective as conventional insecticides against mites and aphids in apple
orchards; psylla in pear orchards; whiteflies, thrips and mites on vegetables;
and whiteflies on cotton. Pear psylla have become resistant even to newer
insecticides, according to Puterka, and mites are becoming resistant.
The drawbacks: The esters must come into contact with the insect to be
effective, and they don't kill insect eggs. Like insecticidal soaps, sugar
esters kill insects by either suffocating them or by dissolving the waxy
coating that protects them from drying environments.
The concept of using sugar esters as an environmentally friendly insect
control started about 10 years ago when ARS scientists in Beltsville, Md.,
found that the leaf hairs of wild tobacco plants exuded a sugar ester to defend
itself against insects and other arthropods.
Scientific contact: Gary J. Puterka, ARS
Appalachian Fruit Research Station,
Kearneysville, W.Va., phone (304) 725-3451 X361, fax (304) 728-2340,