Acaricidal activity of Lantana Camara (Verbenaceae) and Ruta chalepensis (Rutaceae) essential oils against the date palm mite Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae)

Abstract

Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) is a major pest causing substantial economic losses to date palm fruit in southern Tunisia and Algeria, where climatic conditions are very favorable to its development. As part of a study into sustainable management strategies for O. afrasiaticus, two essential oils extracted from Lantana Camara and Ruta chalepensis were tested as adulticides against female O. afrasiaticus mites. For this purpose, an analysis of the chemical composition of these two oils was carried out using the GC-MS method in conjunction with laboratory experiments against fertilised O. afrasiaticus females. The EO of L. camara was mainly composed of caryophyllene (24.33%), Humulene (26.65%) and Muurolene (14.22%). The EO of R. chalepensis was mainly composed of 2-Undecanone (50.52%), 2-Nonanone (11.27%) and 2-Octanol, acetate (9.17%). The acaricidal activity of the EOs against O. afrasiaticus was assessed by contact with females. The LC 50 after 72 h of treatment was 3.198 µL/mL and 8.312 µL/mL for L. Camara and R. chalepensis, respectively. According to the LT 50, the acute toxicity of the EOs to O. afrasiaticus, from high to low, was the Essential Oils L. camara and R. chalepensis at the concentration of 200 µl/ml. In conclusion, the Essential Oils of L. Camara and R. chalepensis have a better acaricidal effect and a high application value for the biological control of O. afrasiaticus, which provides a basis for the development of botanical acaricides.