Comparative ovicidal action of seven plant origin insecticides against the eggs of Bagrada cruciferarum (Kirk.), Pieris brassicae (L.) and Mylabris pustulata (Thunb.)

Comparative ovicidal action of seven plant origin insecticides viz., Abrus precatorius L. (seed-glycosides), Euphorbia nivulia L. (leaf-glycosides), Caesalpinia crista L. (seed-glycosides), Rauwolfia serpentine (L.) Benth. ex Kurz (root-alkaloids), Duranta repens L. (fruit-alkaloids), Hyoscyamus reticulates L. (seed- alkaloids) and Centratherum anthelminticum (Willd.) Kuntze (seed-oils) were studied against eggs of the Bagrada cruciferarum, Pieris brassicae and Mylabris pustulata. The LC_S0 values were found ranging from 0. 31% to 2. 04%, 0. 33% to 1. 26% and 0. 38% to 1. 38%, respectively. Among the botanical extracts tested, C. crista was found to be comparatively most toxic against the eggs of all the three test insects followed by C. anthelminticum. However, A. precatorius and H. reticulatus did not show significant difference, since more than 60% egg mortality was observed. Other plant extracts like R. serpentina, E. nivulia and D. repens were observed to be ineffective ovicides. The influence of varietal resistance on ovicidal activity of botanical extracts was not significant.