Toxicity Bioassay of some Essential Oil Vapour on Various Life Stages of Two-Spotted Spider Mite, Tetranychus urticae (Acari: Tetranychidae) under Laboratory Conditions

A comparative efficacy of five essential oils (EOs) of cardamom (Elettaria cardamomum Maton), Cinnamon (Cinnamomum zeylanicum Blume), Clove (Syzygium aromaticum L.), Eucalyptus (Eucalyptus spp.), and Jasmine (Jasminum spp.) was assessed against two-spotted spider mite (TSSM), Tetranychus urticae. The mites were reared under laboratory conditions and oils were procured from market. Fumigation experiment was done in a glass jar making it airtight. The mortality of mites was recorded after 48 hours of treatment. The result showed that the most potent fumigant was cardamom with highest LC₅₀ values 180.57nlcm^-3, 199.45 nlcm^-3 and 395.36 nlcm^-3 for protonymph, deutonymph and adult respectively. Jasmine (354.05 nlcm^-3), cinnamon (659.13nlcm^-3) and eucalyptus (1033.7 nlcm^-3) were least effective oils for protonymh, deutonymph and adult stages accordingly. All the oils used in the current study have a variable degree of toxicity on different stages of TSSM life cycle. In case of all tested oils, protonymph showed 50% mortality at lower doses(range of value was 180.57 to 354.05 nlcm^-3) but adult needed two to three fold higher doses (range of value was 395.36 to 1033.7 nlcm^-3) than protonymh. The result has revealed that, all these oils have great potentiality to be used as an acaricide in pests control program.