Characterizing Permethrin and Etofenprox Resistance in Two Common Laboratory Strains of Anopheles gambiae (Diptera: Culicidae)
| dc.contributor.author | Gross, Aaron D. | en |
| dc.contributor.author | Bloomquist, Jeffrey R. | en |
| dc.contributor.department | Entomology | en |
| dc.date.accessioned | 2018-10-31T17:00:48Z | en |
| dc.date.available | 2018-10-31T17:00:48Z | en |
| dc.date.issued | 2018-10-22 | en |
| dc.date.updated | 2018-10-31T15:28:20Z | en |
| dc.description.abstract | <i>Anopheles gambiae</i> Giles (Diptera: Culicidae) is the most prolific malaria vector in sub-Saharan Africa, where widespread insecticide resistance has been reported. <i>An. gambiae</i> laboratory strains are commonly used to study the basic biology of this important mosquito vector, and also in new insecticide discovery programs, where insecticide-susceptible and -resistant strains are often used to screen new molecules for potency and cross-resistance, respectively. This study investigated the toxicity of permethrin, a Type-I pyrethroid insecticide, and etofenprox, a non-ester containing pyrethroid insecticide, against <i>An. gambiae</i> at three life stages. This characterization was performed with susceptible (G3; MRA-112) and resistant (A<i>kdr</i>; MRA-1280) <i>An. gambiae</i> strains; the A<i>kdr</i> strain is known to contain the L1014F mutation in the voltage-sensitive sodium channel. Surprisingly, etofenprox displays a lower level of resistance than permethrin against all stages of mosquitoes, except in a headless larval paralysis assay designed to minimize penetration factors. In first-instar <i>An. gambiae</i> larvae, permethrin had significant resistance, determined by the resistance ratio (RR<sub>50</sub> = 5), but etofenprox was not significantly different (RR<sub>50</sub> = 3.4) from the wild-type strain. Fourth-instar larvae displayed the highest level of resistance for permethrin (RR<sub>50</sub> = 108) and etofenprox (RR<sub>50</sub> = 35). Permethrin (PC<sub>50</sub> = 2 ppb) and etofenprox (PC<sub>50</sub> = 9 ppb) resulted in headless larval paralysis (5-h), but resistance, albeit lower, was still present for permethrin (RR<sub>50</sub> = 5) and etofenprox (RR<sub>50</sub> = 6.9). In adult female mosquitoes, permethrin displayed higher resistance (RR<sub>50</sub> = 14) compared to etofenprox (RR<sub>50</sub> = 4.3). The level of etofenprox resistance was different from that previously reported for a similar Akron <i>An. gambiae</i> laboratory strain (MRA-913). The chemical synergists piperonyl butoxide (PBO) and diethyl maleate (DEM) were able to synergize permethrin, but not etofenprox in the resistant strain (A<i>kdr</i>). In conclusion, multiple mechanisms are likely involved in pyrethroid resistance, but resistance profiles are dependent upon selection. Etofenprox is an effective insecticide against <i>An. gambiae</i> in the lab but will likely suffer from resistance in the field. | en |
| dc.description.version | Published version | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.citation | Gross, A.D.; Bloomquist, J.R. Characterizing Permethrin and Etofenprox Resistance in Two Common Laboratory Strains of Anopheles gambiae (Diptera: Culicidae). Insects 2018, 9, 146. | en |
| dc.identifier.doi | https://doi.org/10.3390/insects9040146 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/85611 | en |
| dc.language.iso | en | en |
| dc.publisher | MDPI | en |
| dc.rights | Creative Commons Attribution 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | en |
| dc.subject | knockdown resistance | en |
| dc.subject | kdr | en |
| dc.subject | pyrethroid | en |
| dc.subject | insecticide | en |
| dc.subject | pseudo-pyrethroid | en |
| dc.title | Characterizing Permethrin and Etofenprox Resistance in Two Common Laboratory Strains of Anopheles gambiae (Diptera: Culicidae) | en |
| dc.title.serial | Insects | en |
| dc.type | Article - Refereed | en |
| dc.type.dcmitype | Text | en |