A GENOMIC APPROACH TO UNDERSTANDING HELIOTHIS AND HELICOVERPA RESISTANCE TO CHEMICAL AND BIOLOGICAL INSECTICIDES

Genomics is the comparative study of the structure and function of ent ire genomes. Although the complete sequencing of the genome of any ins ect pest is far in the future, a genomic approach can be useful in the study of mechanisms of insecticide resistance. We describe this strat egy for Heliothis and Helicoverpa, two of the most destructive genera of pest moths (Lepidoptera) worldwide. Genome-wide linkage mapping pro vides the location of major and minor resistance genes. Positional clo ning identifies novel resistance genes, even when the mechanisms are p oorly understood, as with resistance to Bacillus thuringiensis toxins. Anchor loci provide the reference points for comparing the genomes an d the genetic architecture of resistance mechanisms among related spec ies. Collectively, these tools enable the description of the evolution ary response of related, but independent, genomes to the common select ive pressure of insecticides in the environment. They also provide inf ormation that is useful for targeted management of specific resistance genes, and may even speed the search for families of novel insecticid al targets in Lepidoptera.