Increased detoxification via cytochrome P450 monooxygenases (P450, CYP) and insensitivities of target site sodium channel (knockdown resistance, kdr) are the most important mechanisms of pyrethroid resistance in insects. We evaluated the frequencies of two resistance alleles, CYP6D1v1 and kdr, in individual house flies from four field-sites in the eastern USA (Florida, New York, North Carolina and Maine), using a PCR-restriction fragment length polymorphism assay (PCR-RFLP). All these four populations showed high resistance to permethrin. In all populations the frequency of CYP6D1v1 was extremely high with only rare individuals being found that were not homozygous for CYP6D1v1. On the other hand, the frequency of kdr homozygous individuals was quite rare. Our results reveal that CYP6D1v1, rather than kdr, is the most important pyrethroid resistance mechanism in house flies from the eastern USA.
Keywords: P450, population genetics
Back to Display Presentations, Section B. Physiology, Biochemistry, Toxicology, and Molecular Biology
Back to Posters
Back to The 2003 ESA Annual Meeting and Exhibition