Abstract:

Objective: The use of essential oils in mosquito control is considered as a potential alternative of synthetic insecticides. The current study aimed to assess the larvicidal activity of the essential oils extracted from five medicinal plants collected from northeastern Algeria against the Culiseta longiareolata larvae, a vector of the Plasmodium species in birds and one of the most abundant mosquito species in Algeria. Materials and Methods: The essential oils extracted from: Thymus vulgaris, Artemisia herba-alba, Juniperus phoenicea, Rosmarinus officinalis, and Eucalyptus globulus were tested against the 3rd and 4th instar Culiseta longiareolata larvae. The larvae were exposed to a series of concentrations of the tested essential oils for 24h. The concentrations that caused between 10% and 90% mortality were replicated four times, and the entire test was repeated three times. The collected data were used to determine the LC50 and LC90 values, Results: The tested oils revealed an efficient larvicidal activity. T. vulgaris showed 100% mortality at 80ppm final concentration, while the other tested oils showed 100% mortality at 200ppm. Furthermore, the lethal concentrations that caused 50% and 90% mortality (LC50 and LC90) were varying. T. vulgaris was the most efficient essential oil (LC50=25.64ppm, LC90=50.53ppm), followed by J. Phoenicea (LC50=59.83ppm, LC90=137.68ppm), R. officinalis (LC50= 64.18ppm, LC90= 96.55ppm), A. herba-alba (LC50=86.67ppm, LC90=139.55ppm), then E. globules (LC50=95.83ppm, LC90= 168.25ppm). Conclusion: The use of essential oils or their principal active components as α-pinene, 1,8-cineole and Camphor may serve as an eco-friendly method to control mosquito larvae. Nevertheless, the field application of essential oils and their principal components remains a fundamental step to evaluate the field efficacy of these botanic extracts and to note their possible secondary effects on non-targeted organisms. 

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