Ovicidal, acaricidal and growth inhibitory activity of Xanthium strumarium L., Acorus calamus L., and Pongamia pinnata L. (Pierre) against a major pest of tea, Oligonychus coffeae Nietner (Tetranychidae : Acarina)

Abstract

Ovicidal, post-embryonic development and adulticidal activity of petroleum ether, acetone and methanol fractions of Xanthium strumarium (L.), Acorus calamus (L.), and Pongamia pinnata (Pierre), prepared by following sequential extraction method, against the tea red spider mite, Oligonychus coffeae Nietner (Acarina: Tetranychidae) were determined by employing direct exposure method under laboratory conditions. Responses in terms of reduction in egg hatchability, larval-nymphal mortality, adult emergence and mortality of adults varied according to solvent fractions tested, their concentration and developmental stage of the insect. All the solvent fractions of A. calamus and methanolic fraction of X. strumarium possess the property of killing eggs but no ovicidal action was noticed in P pinnata. All the plant extracts adversely affect the postembryonic development as well as adult of red spider mite. The plant extracts described herein merit further study as potential miticides for 0.coffeae control in tea ecosystem.