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The average size of these AgNPs as estimated by particle size distribution was in the range of 50-120 nm. From X-ray diffraction, the AgNP crystallites were found to exhibit face centred cubic structure. aegypti larvae was fully eliminated within the duration of 2.5 h. In addition, comparison of larvicidal activity performance of AgNPs at high concentration prepared using two different methods showed that Ae. As a result, the AgNPs showed moderate larvicidal effects against Ae. In this study, larvicidal activity of silver nanoparticles (AgNPs) synthesised using apple extract against fourth instar larvae of Aedes aegypti was determined. Details on the rearing process and feeding behavior in laboratory, bionomics and notes on habitats are also provided.Įco-friendly synthesis of silver nanoparticles and its larvicidal property against fourth instar larvae of Aedes aegypti.Īli, Zainal Abidin Roslan, Muhammad Aidil Yahya, Rosiyah Wan Sulaiman, Wan Yusoff Puteh, Rustam Larvae and pupae are illustrated and photomicrographed. The immatures were collected from stream margins in the northern Brazilian states Rondônia and Piauí, and subsequently reared to adults. The fourth instar larva and pupa of Atrichopogon delpontei Cavalieri and Chiossone are described for the first time. Marino, Pablo I Spinelli, Gustavo R Ferreira-Keppler, Ruth Ronderos, María M All rights reserved.ĭescription of fourth instar larva and pupa of Atrichopogon delpontei Cavalieri and Chiossone (Diptera: Ceratopogonidae) from Brazilian Amazonia. However, basal AChE activity in fourth instar larvae was significantly higher than basal AChE activity in second to third instar larvae, which could potentially offset the apparent increased sensitivity to the oxon. In terms of AChE depression, fourth instar homogenates were more sensitive to chlorpyrifos and chlorpyrifos-oxon than earlier instars.

riparius were largely determined by differences in uptake rates. In general, it appeared that chlorpyrifos sensitivity differences among second to fourth instar C. In contrast, homogenate AChE activities were responsive in a dose-dependent manner to chlorpyrifos-oxon. Homogenate AChE activities from second to fourth instar larvae were refractory to chlorpyrifos, even at high concentrations. There were no major differences among instars in the biotransformation rates of chlorpyrifos to the more polar metabolites, chlorpyrifos-oxon, and chlorpyridinol (TCP). Earlier instars accumulated chlorpyrifos more rapidly than later instars. In vitro acetylcholinesterase (AChE) assays were performed with chlorpyrifos and the metabolite, chlorpyrifos-oxon, to investigate potential target site sensitivity differences among instars. Specifically, second to fourth instar larvae were exposed in vivo to both low and high waterborne concentrations of chlorpyrifos to examine differences in accumulation rates, chlorpyrifos biotransformation, and overall sensitivity among instars. This research attempted to identify the key biological factors that determined sensitivity differences among life stages of the aquatic insect Chironomous riparius.

Curtis, L.R.Įarly life stages of aquatic organisms tend to be more sensitive to various chemical contaminants than later life stages. Roles of uptake, biotransformation, and target site sensitivity in determining the differential toxicity of chlorpyrifos to second to fourth instar Chironomous riparius (Meigen)īuchwalter, D.B.