Three plant essential oils extracted by hydro-distillation from three medicinal plants namely,clove, Eugenia caryophyllata (Myrtaceae),basil, Ocimumbasilicum and peppermint, Menthapiperita (Lamiaceae) were tested for their fumigant toxic action and repellency effects against adults of the two spotted spider mite, Tetranychusurticae. A filter paper diffusion bioassay without allowing direct contract and dipping method respectively was used. Responses varied according to oil type and dose.In a petri dish 90x10mm as a test chamber at the high dose 200 µl /L air , clove oil gave 100% mortality after 24h of exposure against adult T.urticaewhereas 87.5 and 85.1% mortality were obtained with basil and peppermint oils respectively. The LC50 values of essential oils of clove, basil, andpeppermint against adult T. urticae were 32.2, 66.7 and 62.5 µl/L air, respectively. This indicates that the vapors of essential oil of clove exhibited the highest toxic effect on mites whereas basil and peppermintshowed relatively the least toxic action. Essential oils of clove, basil, and peppermint proven to have repellent effects with ED50s of 1.63, 3.43 and 4.88% respectively.The presentresults show that essential oils of the tested plants have the potential to be used in integrated pest management programs as safer alternative to conventional acaricides to control T.urticae on economic plants in commercial agriculture.
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