Abstract

Extracts of different parts of 12 plant species were evaluated for their potential for acaricidal activity that could lead to the development of new and safe bio-acaricides. The crude methanol extracts of these plants were tested for their acaricidal activity against the two-spotted spider mite Tetranychus urticae Koch in a bioassay under controlled conditions. All the extracts exhibited significant adult mite mortality as compared to control. Lolium perenne L. (flower, leaf), Anthemis vulgaris L. (flower) and Chenopodium album L. (flower, leaf) extracts had significantly higher mortality rates than azadirachtin (10 g/L) and the synthetic pesticides tested at 5% concentration in adhesive tape and residual film method. Our results showed that several plant extracts have good potential for acaricidal activity and are worth further investigation.

Key words: Tetranychus urticae, plant extract, mortality, acaricidal activity.

Abbreviation

TSSM, Two-spotted spidermite; SEM, standard error of mean;LC₅₀, half maximal lethal concentration.