Detection of cyclodiene insecticide resistance‐associated mutations by single‐stranded conformational polymorphism analysis

Cyclodiene insecticide resistance is associated with replacements of a single amino acid within the putative lining of a δ‐aminobutyric acid (GABA)‐gated chloride ion channel gene Resistance to dieldrin (Rdl). Only two resistance‐associated amino acid replacements have been identified; alanine to serine in Drosophila melanogaster, D. simulans, Aedes aegypti , and Tribolium castaneum and alanine to glycine as a second allele in D. simulans. Here we report that single stranded conformational polymorphism (SSCP) analysis of genomic DNA, amplified by the polymerase chain reaction (PCR) for exon 7 of the Rdl gene, can be used to genotype strains or individuals of all of these insects. This technique also appears simultaneously to distinguish between D. melanogaster and D. simulans , sibling species only reliably identifiable by examination of male genitalia. The relative advantages of this genotyping technique against other PCR‐mediated techniques in monitoring for insecticide resistance are discussed.