- Just a spoonful of sugar helps the insects go down --
down the drain, that is.
- The natural sugars that tomatoes, potatoes and wild tobacco
plants give off to drive away insects may be the key to creating an insecticide
that doesn't harm the environment, researchers say. In fact, these sugars
are so harmless that some are approved as food-grade safe.
- Although the insecticide is still two to three years
away from the marketplace, scientists have found that these sugar esters
quickly destroy mites and insects like whiteflies, aphids, thrips and
pear psylla. These insects prey on fruits, vegetables, cotton and other
- Esters -- the chemical means of connecting fatty acids
to sugars -- are a natural defense compound against insects, says Gary
Puterka, entomologist with the U.S. Department of Agriculture's Agricultural
Research Service. "The compound mixes easily with water so it can
be sprayed on any type of plant. It's effective against insects and mites
but it's not toxic to animals or humans," he says.
- In fact, the compound is not digestible by humans.
- Working with AVA Chemical Ventures of Portsmouth, N.H.,
ARS is trying create a man-made sugar ester that can be an insecticide.
- "The natural alternative was to grow wild tobacco,
and it wasn't a good way to get enough material," Puterka says. The
sugar esters kill mites and aphids in apple orchards. "It also works
extremely well against psylla in pear orchards and whiteflies on cotton
and vegetables and in greenhouse plants," he says.
- Recently, pear psylla have developed a resistance to
even newer insecticides, and mites are also becoming resistant. However,
the sugar esters can kill up to 100 percent of the soft-bodied insects
and mites they touch, he says. They kill the bugs by suffocating them
or by dissolving the waxy coating that protects them from drying environments.
- Two drawbacks: The esters must actually touch the insect,
and they don't destroy insect eggs.
- However, these kinds of insecticides will probably be
cheap to make, says Tony Barrington, managing member of AVA Chemical Ventures,
a three-year-old company that primarily develops food additives.
- The ARS has been researching sugar esters over the last
10 years. "It had long been known that the leaf hairs in wild tobacco
had insecticidal properties," Puterka says. "It was assumed it
was nicotine in those leaf hairs. Then ARS scientists started analyzing
the components in them and discovered there was no nicotine. What they
found was sugar esters."
- What To Do
- Stay tuned. These pesticides won't hit the market for
a while, but when they do, they may mean the end of having to beware of
poisons on your lawn and elsewhere.
- If you're wondering why a friendlier pesticide is needed,
consider these previous HealthSCOUT stories about how DDT and PCBs can
lead to pancreatic cancer and how pesticides are interacting more and
more with the environment.
- For more information, take a look at the EPA's Office
of Prevention, Pesticides and Toxic Substances and its section on pesticides
- SIGHTINGS HOMEPAGE
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