Chemical characterization and effect of essential oil from Mexican-tea on twospotted spider mite/Caracterizacao quimica e efeito do oleo essencial de erva-de-santa-maria sobre o acaro-rajado de morangueiro

The twospotted spider mite, Tetranychus urticae Koch (1836) (Acari: Tetranychidae), is the major pest in strawberry. The objective of this study was the chemical characterization of the essential oil of Chenopodium ambrosioides L. and the evaluation of their effects on twospotted spider mite. The compounds of the essential oil were identified by GC/FID and GC/MS analysis. The mortality and oviposition were evaluated after spraying the oil (2.5, 5.0, 7.5 and 10.0% v [v.sup.-1]) on twospotted spider mite females. The yield of the essential oil was of 0.3% and the compounds identified were (Z)-ascaridol (87%), (E)-ascaridol (5.04%), p-cymeno (4.83%), α-terpinene (1.24%) and piperitone (0.7%). The highest values for mortality and reduction of oviposition observed were 85% and 69%, respectively. C. ambrosioides essential oil is a promising option for the management of twospotted spider mite.