Bugs Brain Chemicals Could Be Powerful Weapon Against Crop
May 5, 1998
Artificial copies of insects brain chemicals could play an
important role in preventing the pests from munching on crops.
Service scientists have developed synthetic brain chemicals that
disrupt insect molting, mating and other vital body functions.
These lab-made chemicals mimic natural chemicals in an insects
brain. The chemicals, in proper balance, help the insect grow and
reproduce. But too much--or not enough-- spells trouble. ARS
scientists say the goal is to develop commercial products containing
these artificial chemicals, called neuropeptides, that farmers can
spray onto crops to short-circuit corn earworms and other pests. The
scientists say these products could be developed in about five years.
Inside an insects brain, neuropeptides act as chemical
messengers to stimulate life- sustaining functions. These messengers
are composed of amino acids, the building blocks of protein. The
neuropeptides control molting (shedding of the insects skin),
mating, digestion and water balance.
The biggest challenge the researchers faced was to get the mimics
through the insects tough skin or cuticle. They solved this
problem by replacing some of the amino acids with a combination of
boron, carbon and other chemicals. This new molecule became greasy
just like the insects cuticle, thus making absorption into the
Then came the real test. On tobacco budworm and cotton bollworm
skin, the scientists dabbed their mimic of a neuropeptide that
controls the production of pheromones-- female sex odors that attract
males for mating. Normally, these insects produce pheromones for three
hours. But adding the mimic fueled nonstop pheromone production for 20
hours, meaning the females could be running on empty at mating time.
This research is important because both of these major cotton pests
have adapted to commonly used chemical insecticides. A story about the
research appears in the May issue of Agricultural Research
magazine. The story also is on the World Wide Web at:
Scientific contact: Ronald J. Nachman, ARS Veterinary
Entomology Research Unit, College Station, TX 77845, phone (409)
260-9315, fax (409) 260-9377, email@example.com.