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Spiders

Normally, winter kills most spiders and it takes months for the population to recover. But this spring occupants of the spider motels awakened from hibernation healthy and ravenous. They scuttled into the fields in hordes, ready to attack the insects attempting to suck the life out of the young rice and cotton plants. By protecting the spiders and giving them an early start, the Chinese increased their crop yields and avoided having to use chemical insecticides.

Although the Chinese were the first to harness spider power on a grand scale, agricultural experts in America and other countries have caught on and now are beginning to pamper spiders too.

Often mistaken for insects, spiders actually belong to a different classification of creatures, called arachnids. They are insects' worst enemies, killing far more pests than commercial insecticides do. According to one estimate, spiders devour enough bugs worldwide in a single day to outweigh the entire human population.

At the University of California at Berkeley, Prof. Miguel Altieri plants ground cover between the trees in abandoned apple orchards. This prompts a dramatic rise in the spider population--and dooms many of the little moths whose larvae become the "worms" in bad apples. Altieri estimates that 22 percent more of his crop now is of marketable value.

In Maine, Daniel Jennings of the U.S. Forest Service has enlisted spiders in the war against the spruce budworm, the Northeast's most devastating enemy of spruce and fir forests. Because each spider can eat five or six budworms a day, a legion of spiders can play a major role in preventing an infestation from developing. Spiders attack the much-feared gypsy moth.

Copyright 1989.


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