EFFECT OF THE ESSENTIAL OIL OF Lippia origanoides Kunth AND TWO OF ITS VOLATILE ORGANIC COMPOUNDS ON Tetranychus urticae Koch (Acari: Tetranychidae) AND Bemisia tabaci Genn (Hemiptera: Aleyrodidae) IN GREENHOUSE

Abstract

Background. The use of plant-derived products is an environmentally friendly option to reduce the use of chemical pesticides for pest management. Objective. To evaluate the lethal toxic and repellent effect of the essential oil (EO) of the Mexican oregano (Lippia origanoides) and two of its main components, carvacrol and thymol, on the mortality and repellency of immature B. tabaci and T. urticae in the greenhouse. Methodology. The EO of L. origanoides, carvacrol and thymol at 0.2% and 0.01% were sprayed on eggplant leaves infested with the pests. The mortality of individuals was evaluated at 24 and 48 h and the repellency at 2 and 5 days after application in T. urticae and B. tabaci. Results. The EO and carvacrol at 0.2 % v/v caused 80-99 % mortality in T. urticae and B. tabaci, and EO was the one that caused more than 50 % repellency. The analysis of the L. origanoides EO by gas chromatography – mass spectrometry showed that the major compounds were thymol (41.14 %), p-cymene (14.06 %) and carvacrol (9.25 %). Implication. The essential oil of L. origanoides and of its main components, thymol and carvacrol, represent a viable alternative to manage B. tabaci and T. urticae. Conclusion. The EO of L. origanoides and carvacrol at 0.2 % v/v produce more that 80 % mortality and more that 50 % repellency in T. urticae and B. tabaci

Keywords

• manejo de plagas
• efecto tóxico
• plaguicidas botánicos.