EVALUATION OF INSECTICIDAL ACTIVITY OF MELIACEOUS PLANT EXTRACTS AGAINST Crocidolomia binotalis ZELLER (LEPIDOPTERA: PYRALIDAE)

Abstract

Insecticidal activity of leaf, twig, stem bark and/or seed extracts of seven species of Meliaceae was evaluated against second-instar larvae of Croci dolomia binotalis using lea/residual method. Ethyl acetate soluble fraction of methanolic extract of each plant material was used ill tAts stud) . The feeding treatment for 2 days with seed extracts of Aglaia elliptica, A. hannsiana, A. odoratissima and Iridrilia trijuga at 0.25% caused 98.3, 100, 100 and 91.5% larval mortality, respectively. A. harmsiana ig extract was somewhat active (72.9% larval mortality), Dysoxylum mollissimum bark extract was moderately active (500/0 mortality), T. trijuga leaf and twig extracts were inactive (0% mortality), while the other extracts (A. aspera barks, A. hannsiana leaves, and leaves and twigs of A. elliptica, A. odorata and A. odoratissima) were only weakly active (1.7-28% mortality). Based on mortality of the second and third ins tar, LCso of A. elliptica, A. hannsiana and A. odoratissima seed extracts against C. binotalis larvae were 0.11, 0.03 and 0.04%, respectively. In addition to lethal effect, the active extracts also prolonged the developmental time of the surviving larvae from the second to f ourth instar. For the same plant species, the length of developmental delay caused by extracts of different parts corresponded with the degree of their lethal effect.