Variation in temephos resistance in field populations of Aedes aegypti (Diptera: Culicidae) in the State of Sergipe, Northeast Brazil

Abstract

Introduction:The organophosphate temephos was first used in Brazil in the 1960s for the control of Aedes aegypti. Because of its extensive and longstanding use worldwide, selection for mosquito populations resistant to the chemical has been observed not only in different regions of Brazil but also in several parts of the world. The objective of this study was to evaluate the susceptibility of Ae. aegypti to the organophosphate temephos, a larvicide used in vector control activities in Sergipe/Northeast Brazil. Methods: This study included mosquito populations from seven municipalities of Sergipe and was carried out from October 2010 to August 2011. Qualitative bioassays of diagnostic dose and dose responses were performed. The resistance ratio was calculated based on lethal concentrations for mosquitoes of the susceptible Rockefeller strain. Results: All populations were classified as resistant to temephos. The resistance ratio ranged from 22.2 to 297.9, the lowest being seen in Aracaju, a coastal area of the state, and the highest in Pinhão, a semi-arid region, 96.6km from Aracaju. Conclusions: High levels of temephos resistance were observed in the Ae. aegypti populations of Sergipe. The variation between regions indicates that there have been different regimes of insecticide use and also points to the potential of small cities to generate and spread insecticide resistance.

Synthesis of Esters Containing Cinnamoyl Motif with Potential Larvicide Action: A Computational, Ecotoxicity and in Vitro Cytotoxicity Assessments

“…Lastly, it was performed a quantitative test of the positive control ( Table 2), which has a well‐known mechanism of action directly related to the irreversible inhibition of the enzyme Acetylcholinesterase (AChE). Thus, there was found an increasing LC 50 level compared to the value of 3.0 μg/mL reported in the literature, which has been associated with the Aedes aegypti larvae's resistance to this insecticide [28,29] …”

“…Thus, there was found an increasing LC 50 level compared to the value of 3.0 μg/mL reported in the literature, which has been associated with the Aedes aegypti larvae's resistance to this insecticide. [28,29]…”

Efektivitas Tablet Bacillus thuringiensis H-14 Isolat Salatiga terhadap Jentik Aedes aegypti pada Dua Sumber Air yang Berbeda

“…4 Penelitian menyebutkan bahwa penggunaan temephos secara terus menerus dapat menyebabkan resistensi. 5,6 Selain itu penggunaaan larvasida dapat menyerang organisme non-target serta berdampak buruk pada kesehatan lingkungan. 7 Pengendalian jentik nyamuk vektor secara biologis menggunakan bahan yang berasal dari agen biologi seperti bakteri Bacillus thuringiensis H-14.…”

Evaluation of the influence of calcium chloride on the behavior of phases of nanosystems applied in the larvicidal control of Aedes aegypti

“…aegypti, which are the organochlorines, carbamates and pyrethroids (Aguiar, 2017;Maia et al, 2019). However, the continuous use of these insecticides over the years has shown worrying results regarding the selection of resistant individuals (Corte et al, 2018;Fonseca et al, 2019;Martins et al, 2021).…”