With pride and satisfaction, a farmer eyes the glistening red globes of the tomatoes he has just harvested. A few years ago he had been ready to abandon tomato farming because the destructive tomato pinworm was ruining as much as two-thirds of his crop. Despite his zealous use of insecticides, these worms would tunnel into his tomatoes, leaving telltale pinholes and unsightly black blotches that destroyed the crop’s marketability.
But now, spiraling around the stems of many of his tomato plants, are dispensers of a potent chemical guardian. These hollow plastic tubes emit a chemical that interferes with the ability of the pinworm moth to find mates, and breaks the cycle of infestation. Thanks to pinworm birth control, the farmer was able to bring three-quarters of his crop to market this year.
The farmer’s success story is the result of more than a century’s worth of investigation by entomologists
and chemists bent on solving such mysteries as how a moth lures mates from far and wide, or how an ant lets her whole colony know the location of a food source. Scientists looking for new methods of pest management then expanded on this basic research. As a result, farmers of many kinds of crops now have highly effective weapons for their perennial battle against insect pests.
The new weapons use chemical substances generated by the insects themselves. Unlike conventional pesticides, the chemicals, known as pheromones, do not damage other animals, nor do they pose health risks to people. Pheromones specifically disrupt the reproductive cycle of harmful insects. They also can be used to lure the pests into traps that help farmers track insect population growth and stages of development. In this way, farmers can reduce the amount of insecticide they need – spraying only when the insects are in a vulnerable stage or when their numbers exceed certain levels.
The following article explores the trail of research that ultimately led to the design of pheromone-based pest management. The story behind the measures that are beginning to transform agriculture provides a dramatic example of how science works, by illustrating how basic research produces knowledge that can lead to practical results of human benefit.
