More ominous , several important insects have developed resistance to every major insecticide. In the state of Gujarat in India, for instance, the mosquitoes that transmit malaria are resistant to every affordable insecticide, and malaria rates are surging. Similarly in the northeastern United States, the Colorado potato beetle has become resistant to at least 15 chemicals, leaving potato growers dependent on a compound not yet formally approved for potatoes.

　　Pesticides also create new pests because they destroy the spiders, wasps and predatory beetle that naturally keep most plant-feeding insect populations in check. The brown plant hopper that plagued Indonesian rice fields in the 1970s and 80s was not a serious problem until 1970, shortly after heavy insecticide use began. In the United States, such major pests as spider mites and cotton bollworm were nuisances at most until spraying decimated their

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