Abstract
The mosquito Aedes aegypti is the main focus of dengue control campaigns. Because of widespread resistance against conventional chemical insecticides, chitin synthesis inhibitors (CSIs) are considered control alternatives. We evaluated the resistance status of four Brazilian Ae. aegypti populations to both the organophosphate temephos and the pyrethroid deltamethrin, which are used in Brazil to control larvae and adults, respectively. All vector populations exhibited high levels of temephos resistance and varying rates of alterations in their susceptibility to pyrethroids. The effect of the CSI novaluron on these populations was also investigated. Novaluron was effective against all populations under laboratory conditions. Field-simulated assays with partial water replacement were conducted to evaluate novaluron persistence. Bioassays were continued until an adult emergence inhibition of at least 70% was attained. We found a residual effect of eight weeks under indoor conditions and novaluron persisted for five-six weeks in assays conducted in an external area. Our data show that novaluron is effective against the Ae. aegypti populations tested, regardless of their resistance to conventional chemical insecticides.
Highlights
Among the arboviruses transmitted by mosquitoes throughout the world, dengue is presently the most relevant; it is endemic to all of the continents, except Europe (Nogueira et al 2001, Forattini 2002, Claro et al 2004)
In Brazil, the organophosphate temephos has been used for decades to control the larvae of the dengue vector Ae. aegypti and reports of temephos resistance date from
The resistance ratios (RRs) values obtained in this work indicated temephos resistance in all of the populations evaluated
Summary
Among the arboviruses transmitted by mosquitoes throughout the world, dengue is presently the most relevant; it is endemic to all of the continents, except Europe (Nogueira et al 2001, Forattini 2002, Claro et al 2004). The only way to control the dengue epidemiological network is to target the virus’ vector, Aedes aegypti (Medronho 2006, Braga & Valle 2007). The elimination of potential Aedes breeding sites is increasingly considered a crucial component of dengue control, the utilisation of chemical insecticides is still a common measure. The most commonly used insecticides against Aedes in Brazil were the organophosphate temephos and the pyrethroid deltamethrin, which are used to control the larval and adult populations, respectively (Braga & Valle 2007). In contrast to the classical chemical insecticides and biolarvicides, IGRs are not directly toxic, but act selectively on the development, metamorphosis or reproduction of the target insect species (Hoffmann & Lorenz 1998, Martins & Silva 2004). Among IGRs, the chitin synthesis inhibitors (CSIs) act by interfering with the synthesis or deposition of chitin on the exoskeleton or other chitinised internal structures, such as the peritrophic matrix (Merzendorf & Zimoch 2003, Merzendorf 2005)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
