This is Steve Ember with the VOA Special English AgricultureReport.
Biocontrols are the way nature seeks balance. Consider theexample of insects that attack crops. Other creatures eat thesepests, unless natural controls are missing.
Biocontrols can also include organisms like worms and fungi. Andthey come in the form of bacteria and viruses. These are calledpathogens. A good example is a disease that affects Japanesebeetles.
These beetles were accidentally brought to the United Statesalmost one-hundred-years ago. They ate crops and spread out ofcontrol.
But in the nineteen-thirties, researchers discovered some youngbeetles infected with a condition known as milky disease. Theresearchers found the bacteria that caused this infection. They putit on the soil for other beetles to eat.
The government used hundreds of tons of the bacteria, calledBacillus popilliae (ba-SI-lus po-PILL-ee-eye). It controlled theJapanese beetles. But today it seems less effective. Another controlmay be needed.
Plants may also find themselves in a new home where they canreproduce quickly. The alligator weed native to South America is onesuch plant. It came to the United States and took over wetlands andrivers in several states in the South.
In nineteen-sixty-four, researchers released flea beetles inFlorida. Flea beetles are also from South America. They like to eatalligator weed. The beetle solved the weed problem in centralFlorida. There was no need for further use of plant poisons. Thiscase serves as a model of biological weed control.
There are three methods for biocontrol. One is conservation.Experts say this is probably the most important. Natural enemies ofpests must be protected. This means to avoid treating crops withchemicals that will harm any helpful insects.
A second method is often called classical biological control.This means a helpful biocontrol is released to fight a pest problem.The release of ladybeetles to fight aphids on plants is another suchexample.
Finally, there is the method of biocontrol that experts callaugmentation. Helpful organisms are added to fields to improveenvironmental balance.
Cornell University in Ithaca, New York, has a full Web site onbiocontrol. You can find a link at our site,voaspecialenglish-dot-com. Or enter the words “Cornell” and”biocontrol” into a search engine on the Internet.
This VOA Special English Agriculture Report was written by MarioRitter. This is Steve Ember.