Lethal and sublethal effects of essential oils on Tetranychus neocaledonicus (Acari: Tetranychidae)

Abstract

Essential oils have shown promising results regarding their activity on mites. However, information on mite life history is scarce. This study aimed to chemically characterize essential oils from lllicium verum, Eugenia caryophyllus, and Cymbopogon flexuosus, and to evaluate the lethal and sublethal effects of these oils on the life history traits of Tetranychus neocaledonicus André 1993. Trans-anethole and eugenol were the main components of I. verum and E. caryophyllus, respectively, and in C. flexuosus, the monoterpenes geraniol and neral stood out. Essential oils from I. verum, E. caryophyllus, and C. flexuosus showed different toxicity degrees to adults of T. neocaledonicus and decreased egg viability. All oils tested were classified as repellents for T. neocaledonicus females and caused oviposition deterrence. The survival of the parental generation of T. neocaledonicus was not affected by l. verum, E. caryophyllus, and C. flexuosus oils. However, E. caryophyllus was affected in the F1 generation. There was a reduction in the total fecundity of T. neocaledonicus compared to the parental generation. Life table parameters were affected in the F1 generation. Only the average length of a generation was decreased by essential oils in the parental generation. lllicium verum, Eugenia caryophyllus, and Cymbopogon flexuosus essential oils have lethal effects on adults and eggs of T. neocaledonicus, and exposure to sublethal concentrations affects the F1 generation of T. neocaledonicus by decreasing fecundity and altering life table parameters in this generation.