Bioefficacy of Artemisia herba-alba Asso. Essential Oil Against Culex pipiens (Diptera: Culicidae): Chemical Composition, Larvicidal Activity, and Sublethal Effects on Morphometry and Energy Reserves

OpenAlex İngilizce

Objectives This research aims to identify the chemical composition of Artemisia herba-alba Asso. essential oil (AHA EO) and assess, under laboratory conditions, its larvicidal activity via the sublethal concentrations’ effects on the morphometric and biochemical parameters of Culex pipiens ( Cx. pipiens ) mosquito larvae. Methods The EO was extracted from dry aerial parts of A. herba-alba through hydrodistillation, and characterized utilizing GC-FID and GC-MS. The larvicidal efficacy of AHA EO against fourth-instar larvae of Cx. pipiens , was evaluated at 24, 48, and 72 h of exposure, following the World Health Organization (WHO) protocol, with temephos as the reference control. Dose-response mortality data were subjected to probit analysis to determine the lethal concentration (LC 90 ). Subsequently, the impact of the sublethal concentrations (LC 25 , LC 50 ) was assessed on the morphometric parameters (body weight and volume) and the key biochemical components (proteins, lipids, and carbohydrates). Statistical significance between control and treated groups, was determined using one-way analysis of variance (ANOVA), followed by Tukey’s post-hoc test. Results The chemical analysis revealed that the oil, with a yield of 0.97±0.28% (w/w), is composed mainly of thujone (32.46%), chrysanthone (18.22%), camphor (17.60%), chrysanthenone (9.72%), and 1,8-cineole (6.15%) among 24 identified components. The EO exhibited strong larvicidal activity after 24 hours, with LC 50 and LC 90 values of 61.44 ppm and 114.10 ppm, respectively. Acute exposure to sublethal concentrations decreased the weight and volume size of surviving larvae, with a significant prolonged effect observed at 72 hours. Furthermore, biochemical analysis revealed a disruption in metabolic homeostasis, characterized by elevated protein content and marked depletion in carbohydrate and lipid reserves. Conclusion AHA EO is a highly effective botanical larvicide that impairs Cx. pipiens growth and metabolic homeostasis. These findings highlight its potential as an eco-friendly alternative for mosquito population management and for preventing West Nile virus transmission.