This is Steve Ember with the VOA Special English AgricultureReport.

Biological controls are living things that eat organisms harmfulto crops. They offer new ways for farmers to grow organic crops andprotect the environment.

In modern times, farmers have depended on chemicals to killharmful insects, plants and other organisms. But, many scientistsand farmers are looking for ways to grow crops without usingpoisons. Limiting chemicals can save farmers money as well. One wayto avoid using poisons is to release helpful insects that arenatural enemies of harmful insects, or pests.

Some insects eat pests. The lady beetle, or ladybug, is wellknown. Round, colorful lady beetles eat many kinds of harmfulinsects including aphids. Aphids develop colonies and eat plantfluids.

An adult lady beetle can eat fifty or more aphids a day. Aphidsattack many different kinds of crops. This makes lady beetles a gooddefense against aphids for growers of fruit, grains, beans,strawberries and other crops. Lady beetles live in Asia, Europe andthe Americas. Farmers can buy them from suppliers.

Some insects inject their eggs inside the bodies of pests. Theseare called parasitoids. Young parasitoids come out of their eggs andeat the pests. Some parasitoids can be very effective. They keep thepests from reproducing. After they become adults, they lay many eggson other pests.

A tiny wasp with a big name is a good example. Encarsia formosais used all over the world for vegetables and flowers grown indoors.

The Encarsia formosa wasp injects eggs into the bodies of youngwhite flies. There are many different kinds of white fly pests and Eformosa likes to eat at least fifteen of them. Some of these waspscan lay enough eggs to kill ninety-five young white flies in twelvedays. E. formosa is most popular in Russia and Europe.

The United States Department of Agriculture has been studying afly that attacks another pest - the fire ant. The phorid fly attacksfire ants in the same way as E. formosa. Phorid flies kill onlyabout three percent of the ants in a colony. But they greatly damagethe colony's ability to collect food. The U.S.D.A. has releasedphorid flies in an effort to control fire ants in the southeasternUnited States.

Next week, we tell about two kinds of biological controls thatattack pests in new ways.

This VOA Special English Agriculture Report was written by MarioRitter. This is Steve Ember.