COMPATIBILITY OF NIMBECIDINE AND TRICEL WITH ENTOMOPATHOGENIC NEMATODE, HETERORHABDITIS BACTERIOPHORA

A laboratory study was conducted to study of compatibility of entomopathogenic nematode, Heterorhabditis bacteriophora with insecticides currently used against cutworm (Agrotis ipsilon). To evaluate the nematode survival rate, infective juveniles (IJs) H. bacteriophora were exposed to Nimbecidine and Tricel at three different concentrations for 3 h,6 h, 12 h and 24 h. The surviving nematodes were used to determine the infectivity, penetration rate and reproduction potential in last instars cutworm larvae. Data showed that the survival rate of nematodes exposed to Nimbecidine and Tricel was 53% and 50% respectively. H. bacteriophora was found to be virulent with the A. ipsilon mortality (60 % to 70%).Penetration rate of IJs of H.bacteriophora in A. ipsilon larvae reached 55.5% when exposed to Nimbecidine at 0.125%. H.bacteriophora was more susceptible to chlorpyriphos than Nimbecidine. H. bacteriophora infectious ability and reproduction rate in A. ipsilon was found to be reduced in exposure of chlorpyriphos