EFFICACY OF SOME PLANT OILS AND GROWTH REGULATORS ON TWO-SPOTTED SPIDER MITE

ABSTRACT: Two-spotted spider mite, Tetranychus urticae Koch, is one of the most damaging pests of many economically important crops. The acaricidal, ovicidal and nymphal activity of three essential plant oils viz. neem, mahagoni, castor and two insect growth regulators viz. buprofezin and lufenuron + Emamectin benzoate were evaluated against T. urticae under laboratory conditions and in the potted plants. Results showed that mahagoni oil (100%) and lufenuron + emamectin benzoate(100%) performed the most efficient acaricidal agent againstT. urticae in the laboratory conditions. Mahagoni oil also showed the highestovicidal efficacy (77.2%)and lufenuron + emamectin benzoate (74.6%) showed the second highest ovicidal efficacy against T. urticae. Castor oil showed the lowest percent of ovicidal efficacy (48.1%). In the case of the nymph, the highest average mortality was observed in mahagoni oil (55.4%) followed by lufenuron + emamectin benzoate (52.8%). The lowest nymphal mortality was observed in castor oil (31.3%). In potted bean plants, all the treatments showed a significant reduction in the adult population over control up to 21 days. The adult T. urticae population’s survival rate progressively declined throughout the  length of the days  after treatment (DAT) for  each treatment up to sevendays, then slightlyclimbed up to 21 days. However mahagoni oil (77.8%) and lufenuron + emamectin benzoate (72.2%) showed the highest mite mortality  compared to all other treatments. Thereforemahagoni oil and lufenuron + emamectin benzoatewere found to be the most effective to control T. urticae.

Keywords: Country bean, Tetranychusurticae, mortality, plantoils.