Behavioural Reponse of Two Spotted Spider Mite, Tetranychus urticae Koch to Resistance and Susceptible Sources of Okra, Abelmoschus esculentus (L.)

Field and laboratory studies were conducted toscreen test entries including varieties/hybrids/local seeds and one wild type of okra for their resistance against Tetranychus urticae Koch. Based on the mean mite population and damage score, six entries viz., Kasturi bhendi, (R), Dharmapuri local (MR), Parbani Kranti (MR), Pusa Sawani (MR), COBhH1 (MR) and Mahyco 10 (S) were selected for further investigations. Among the selected six entries of okra in multiple choice tests maximum number of mites chose the susceptible check Mahyco 10 (23.33%) and the minimum number of mites (9.33%) showed preference to resistant Kasturi bhendi after 24. Kasturi bhendi repelled mites (68.00%), while mites that repelled from Mahyco 10 was the least (40.00%). Olfactometer meter studies were made to study the preference of bhendi showing various host plant reactions against two spotted spider mite. The olfactometer studies revealed a significant response of T. urticae to the odour from different okra leaves. More number of mites showed positive responses towards the susceptible check Mahyco 10 (15) than the resistant Kasturi bhendi (5) and moderately resistant COBhH1 (15).