Compatibility of Steinernema asiaticum and Heterorhabditis bacteriophora with registered Insecticides and Bt for Control of Plutella xylostella under laboratory Conditions
Kumar, Rajesh; Singh, Ram; Walia, Rim Kim; Walia, Kum Kum
Two species of EPNs i. e, Steinernema asiaticum (Anis, Sgahina, Reid et al 2002) and Heterorhabditis bacteriophora (Poinar 1976) and three insecticides (Endosulfan 35EC, Malathion 50EC and Bt) registered to control Plutella xylostella (Linnaeus 1758) in cabbage were tested for compatibility in laboratory assays. Double strength concentrations of endosulfan (0.035%, 0.07%), malathion (0.025%, 0.05%) and Bt formulation (0.1%, 0.2%) were prepared in distilled water. Infective Juveniles (IJs) of S asiaticum and H bacteriophora @ 100 per ml sterile distilled water were added in Petri plates (4 cm dia) to equal amount of insecticide preparation to get the required concentration. Observations were recorded on mortality of nematodes after 24 and 48h. Minimum IJ mortality 0.87 and 1.59 per cent was recorded in Bt (0.1%) in S asiaticum and H bacteriophora, respectively. Maximum mean IJ mortality 6 and 12.4 per cent was recorded in endosulfan (0.07%) in S asiaticum and H bacteriophora, respectively. The effect of time factor alone and interaction between time and concentration of insecticides was non-significant. Overall, negligible IJ mortality was recorded. It is inferred that the two species of EPNs can be incorporated in IPM programme for the management of P. xylostella.