Bruce E. Tabashnik and Richard T. Roush Pesticide resistance is an increasingly urgent worldwide problem. Resistance to one or more pesticides has been documented in more than 440 species of insects and mites. Resistance in vectors of human dise8se, particularly malaria-transmit- ting mosquitoes, is a serious threat to public health in many nations. Agricultural productivity is jeopardized because of widespread resistance in crop and livestock pests. Serious resistance problems are also evident in pests of the urban environ- ment, most notably cockroaches. Better understanding of pesticide...