Relative larvicidal potentiality of nano-encapsulated Temephos and Imidacloprid against Culex quinquefasciatus

•Efficacy of encapsulated temephos and imidacloprid within biodegradable, polyethylene glycol (PEG) against culicine larvae•Encapsulation was done by melt-dispersion method.•Comparison of encapsulated formulations with their non-capsulated forms•Nanoparticles loaded with 8% temephos were found most potent.•Average size of most potent encapsulated formulations was 129.5 nm.

Encapsulation of temephos ranging from 1% to 16% and imidacloprid from 1% to 8% within biodegradable and biocompatible, polyethylene glycol in different ratios was done by using melt-dispersion method. The efficacy of encapsulated forms was evaluated and compared with their non-capsulated forms against larvae of Culex quinquefasciatus. The encapsulated temephos was more toxic than the encapsulated imidacloprid with LC50 values of 0.013, 0.010 and 0.003 mg/L after 24, 48 and 72 h, respectively. No doubt, the non-capsulated temephos and imidacloprid were more effective as compared to their encapsulated forms. However, the same mortality rate was achieved by the slow release of lesser amount of pesticides after encapsulation, e.g., 0.003 mg/L for 8% temephos formulation and 0.019 mg/L for 4% imidacloprid as compared to their non-capsulated form of temephos and imidacloprid (0.004 and 0.021 mL/L) after 72 h of exposure. Thus, encapsulated forms are more economical and eco-friendly due to controlled slow release of their nanoparticles.

Graphical abstractThe larvicidal potentiality of nano-encapsulated temephos and imidacloprid was evaluated and compared with their non-capsulated forms against culicine larvae. Nano-encapsulated temephos was found effective.Figure optionsDownload full-size imageDownload as PowerPoint slide