Direct and indirect effects of leaf extracts of Vitex spp. on okra red spider mite Tetranychus macfarlanei Baker and Pritchard (Acari: Tetranychidae)
Nandini KN and Srinivasa N
Laboratory study was carried out in the Acarology section of Dept. of Agril. Entomology, University of Agril. Sciences, Bengaluru during the period 2015-2016 to determine direct (mortality) and indirect (repellence and oviposition deterrence) effects of various organic solvent (such as petroleum ether, diethyl ether, ethyl acetate and methanol) extracts from the leaves of Vitex spp. namely, V. altissima, V. negundo (white type), V. peduncularis and V. trifolia on okra red spider mite, Tetranychus macfarlanei. Among the different solvent extracts of Vitex spp., methanol extract showed comparatively more acaricidal potential followed by ethyl acetate, diethyl ether and petroleum ether extracts. Repellence caused by methanol leaf extract of V. trifolia was highest i.e.76%, while it was moderate (48-49%) with V. altissima & V. negundo extracts and was lowest (37%) with V. peduncularis extract. Maximum mortality of okra spider mites observed was 79% with methanol leaf extract of Vitex peduncularis compared to other species of Vitex (71 to 77% mortality). On methanol extract treated leaf discs female mites laid relatively less number of eggs in three days period (0.40 to 1.89 eggs) compared to that on water treated control leaf discs (1.83 to 4.64 eggs).
Nandini KN, Srinivasa N. Direct and indirect effects of leaf extracts of Vitex spp. on okra red spider mite Tetranychus macfarlanei Baker and Pritchard (Acari: Tetranychidae). J Entomol Zool Stud 2018;6(4):465-469.