Location: Mosquito and Fly ResearchTitle: Pyrethroid resistance alters the blood-feeding behavior in Puerto Rican Aedes aegypti mosquitoes exposed to treated fabric
|AGRAMONTE, NATASHA - University Of Florida|
|BLOOMQUIST, JEFFREY - University Of Florida|
Submitted to: PLOS Neglected Tropical Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2017
Publication Date: 9/20/2017
Citation: Agramonte, N.M., Bloomquist, J.R., Bernier, U.R. 2017. Pyrethroid resistance alters the blood-feeding behavior in Puerto Rican Aedes aegypti mosquitoes exposed to treated fabric. PLOS Neglected Tropical Diseases. 11(9):e0005954. https://doi.org/10.1371/journal.pntd.0005954.
Interpretive Summary: One of the ways that United States military and civilians can protect themselves from mosquito bites is by wearing clothing that is impregnated with permethrin. Just recently, a second chemical (etofenprox) was registered for use in clothing. There is an increasing concern that the development of resistance to insecticides in mosquitoes may allow them to bite through clothing more easily than mosquitoes that either have less or no resistance to insecticides. In this study, ARS researchers in Gainesville, Florida, and at the University of Florida tested a resistant Puerto Rico strain of Aedes aegypti walong with the susceptible strain for the ability of the mosquitoes to bite through worn fabric treated with the insecticides. It was determined that the resistant mosquitoes had an easier time feeding through the fabric for both chemicals; however, the resistance for repellency was not as great as the resistance to toxicity (ability to kill the mosquitoes). This results of this research will be of importance to the United States Military and civilians at home and traveling abroad.
Technical Abstract: Emerging insecticide resistance is a major issue for vector control; it decreases effectiveness of insecticides, thereby requiring greater quantities for comparable control with a net increase in risk of disease resurgence, product cost, and damage risk to the ecosystem. Pyrethroid resistance has been documented in Puerto Rican populations of Aedes aegypti mosquitoes. In the present study, topical toxicity to five insecticides was determined for susceptible (Orlando - ORL) and resistant (Puerto Rico - PR) strains of Aedes aegypti. Resistance ratios were calculated using LD50 values, and high resistance ratios for permethrin (112) and etofenprox (228) were observed for the Puerto Rico strain. Behavioral differences in blood-feeding activity for pyrethroid-resistant and pyrethroid-susceptible strains of Aedes aegypti when exposed to pyrethroid-treated cloth were also explored. Strains were exposed for 15 min to a range of concentrations of pyrethroid-treated uniform fabric in a cage that contained 60 female Aedes aegypti mosquitoes. Results showed a rightward shift in the dose-response curves for blood-feeding that indicated higher concentrations of pyrethroids were necessary to deter blood-feeding behavior in the pyrethroid-resistant Puerto Rican strain of Aedes aegypti. Interestingly, the resistance ratios for blood-feeding were similar for permethrin (61) and etofenprox (70), but were lower than their respective resistance ratios for topical toxicity, suggesting that knockdown resistance was the primary mechanism of resistance in the blood feeding assays.