The basic facts of genetic resistance to insecticides have been known for decades. This is from 1987:

> Resistance to one or more insecticides had been reported in at least 447 species of insects and mites by 1984. As a result of cross and multiple resistance, many insect and mite pests are able to tolerate virtually all pesticides available for their control. An extreme example is the Colorado potato beetle,Leptinotarsa decemlineata, on Long Island,New York,which has developed resistance to all major classes of modem synthetic insecticides.

> Therefore, it is essential to develop strategies to delay or minimize the probability of resistance evolution. This will be possible only if the genetics of resistance and population ecology of pest species are defined in a manner that is relevant to actual pesticide use. ... this has been recognized since the 1950s ... The only widely applied method for avoiding resistance has been reduction of pesticide use, which has been a primary motivation for the development of integrated pest management systems.

> High doses of insecticides can make the toxicological phenotype of resistance effectively or functionally recessive by killing the heterozygotes. A lower dose can make resistance effectively dominant. However, dominance is a property of phenotypic characters, not of alleles. The dominance of resistance alleles for other characters, such as fitness in the absence of pesticide exposure, does not have to be the same as dominance for toxicological phenotype

ECOLOGICAL GENETICS OF INSECTICIDE AND ACARICIDE RESISTANCE
Ann. Rev. Entomol. 1987. 32:361

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