Abstract

Three entries of okra, No. 55, Arka Anamika and AE 9, identified as highly susceptible, susceptible and resistant, respectively to Earias vittella and Helicoverpa armigera during earlier field screening were selected and the kairomone effect of acetone extracts of their plant parts (flowers, tender and mature fruits, tender and mature leaves) to enhance the activity of Trichogramma chilonis and ` was studied under laboratory condition. Acetone extract of flowers of No. 55 (1% or 10,000 ppm) enhanced the parasitism/predation by T. chilonis and C. zastrowi silemi on eggs of E. vittella, recording 55.33 and 58.33%, respectively while it was 6.67 and 10.67% in control (acetone). Similarly, the flower extract of No. 55 enhanced the activity of T. chilonis and C. zastrowi silemi by 65.33 and 68.67% on eggs of H. armigera, as compared to 10.67 and 12.55% in control.

Keywords: Chrysoperla zastrowi silemi, Earias vittella, Helicoverpa armigera kairomone, Okra, Trichogramma chilonis