Persistence and Bioefficacy of Bifenthrin as Termiticide In Building Foundation

Persistence and bioefficacy (as termiticide) of bifenthrin, a new generation pyrethroids insecticides, was studied under subtropical conditions. Bifenthrin (Biflex 2.5 EC) was applied @ 7.5, 15, 22.5 and 30 kg ha−1 in 17 × 17 inch plots having termite infestation. The bioefficacy of bifenthrin was studied in terms of the damage caused by termites to the wooden block placed in the centre of plot in touch with soil surface. The persistence was studied by estimating residues of bifenthrin in soil at different depths also. The bifenthrin residues from soil were extracted using acetone. The extracts were cleaned up on florisil column and residues were quantified on GC-ECD using BPX-50 column. Bifenthrin was found persistent in soil for more than 53 months. The residues were detected upto 60 cm depth in soil. In the deeper layers amount of residues was very less as compared to that in surface layers. It thus formed effective barrier to the penetration of termites in soil. At 22.5 and 30 kg ha−1spray, bifenthrin residues were high enough to completely deter termites from attacking wooden block. At 15 kg ha−1 application also only slight damage was observed after 53 months of treatment. Bifenthrin was found to provide effective termite control for more than 53 months after application at 22.5 kg ha−1 or more concentration. It can be safely used as household termiticide as it doesn't pose threat of ground water contamination.