First report of the effect of lambda-cyhalothrin on the activity of acetylcholinesterase, glutathione S-transferase, and cytochrome C-oxidase enzymes in larvae of Culex quinquefasciatus (Diptera: Culicidae) in East Jakarta

Abstract

Bancroftian filariasis is a vector-borne disease transmitted by the Culex quinquefasciatus. Heavy and long-term use of insecticides causes the development of insecticide resistance in Cx. quinquefasciatus. However, there has been no research on resistance mechanisms through detoxifying enzyme activity in Cx. quinquefasciatus mosquitoes exposed to lambda-cyhalothrin in Jakarta. This study aimed to determine the larvicidal activity of lambda-cyhalothrin against Cx. quinquefasciatus larvae and the larvicidal mechanism through detoxifying enzyme activity. Bioassay tests were performed by exposing Cx. quinquefasciatus larvae to five concentrations of lambda-cyhalothrin (0.002; 0.015; 0.05; 0.2; 0.7 ppm). The mortality rate was measured after 24 h of exposure. The detoxifying enzyme activity, including acetylcholinesterase (AChE), glutathione s-transferase (GST), and cytochrome c-oxidase (COX), was analyzed using the biochemical method. Lambda-cyhalothrin (0.7 ppm) showed 100% mortality of Cx. quinquefasciatus larvae. LC₅₀ dan LC₉₀ values were 0.054 and 0.148 ppm, respectively. Lambda-cyhalothrin non-significantly increased AChE activity (P > 0.05), significantly increased GST activity (P < 0.05), and non-significantly decreased COX activity (P > 0.05). Lambda-cyhalothrin is still effective in killing Cx. quinquefasciatus larvae by influencing detoxification enzymes.