ABSTRACT
Chemical and biological insecticides are indispensable in modern agriculture for controlling damage to food and ber crops by insect pests. One of the many problems resulting from this dependency is the frequent and widespread occurrence of insecticide resistance. Resistance is dened as a genetically based decrease in the susceptibility of a population to a toxin over time, in response to long-term exposure. The mechanism of this decrease is an evolutionary response of the population to differential mortality from the toxin, causing the frequencies of alleles controlling resistance mechanisms to increase over several generations. Insecticide resistance is a global problem, with more than 450 pest species displaying resistance to at least one insecticide (Mota-Sanchez, Bills, and Whalon 2002).
