Essential oil of Lavandula dentata L. (Lamiaceae) as a potential larvicidal agent against Aedes mariae (Diptera: Culicidae), an invasive species from the coasts of Algeria

Abstract

The species Aedes mariae (Sergent & Sergent, 1903) (Ae. mariae) is a mosquito that breeds in rock pools on the Mediterranean coast and unfortunately has not been the subject of much analysis. The present study was undertaken to develop a new method of Culicidae control. In recent decades, studies have intensified on plants and their extracts’ toxic effects. Therefore, as far as Lavandula dentata is concerned the Essential oils (EO) are being extracted from this plant first by Hydrodistillation, and then by gas chromatography-mass spectrometry to determine its chemical composition as a take-off point. These EO analysis findings contained 23 compounds, the main ones being eucalyptol (40.45%) followed by camphor (19.85%) and D-limonene (7.98%). The toxicological tests were carried out in accordance with World Health Organization (WHO) techniques, followed by the determination of lethal and sub-lethal concentrations (LC10, LC25, LC50, and LC90), giving the following results respectively after 24 hours: (396. 2 μg/ mL; 515.3 μg/mL; 670.2 μg/mL and 1134 μg/mL); 48 hours (297.4 μg/mL; 529 μg/mL; 940.9 μg/mL; 2977 μg/mL), and 72 hours (208.7 μg/mL; 411.1 μg/mL; 810 μg/mL; 3144 μg /mL). In the long run, the two sub-lethal toxic effects on the biomarkers were determined. The results prove an inhibition of Acetylcholinesterase (AChE), as well as an increase in Glutathione S-transferases (GST) and Malondialdehyde (MDA). This confirms its larvicidal activity against Ae. mariae. Based on the results obtained, it has been concluded that it can be used as an alternative to synthetic insecticides in biological anti-culicidae control.