Vol. 10, Special Issue 5 (2021)

Author(s):
N Sathiyamoorthy, K Senthilvel, N Rani, K Ramya, G Ponnudurai and R Velusamy

Abstract:
In this study adult house flies were collected in five poultry farms from different blocks of Namakkal, Tamil Nadu. The collected flies were reared in laboratory. Pyrethroid resistance was assessed in Three to five days old F1 generation flies by topical and residual contact methods. In this study, different concentrations of cypermethrin was used for such as 0.0002, 0.0005, 0.001, 0.002, 0.004, 0.008, 0.01 µg (a.i)/µl and 0.03, 0.06, 0.12, 0.24, 0.48 and 0.96 µg(a.i)/cm² were used for topical and residual contact assays respectively. House fly strains collected from three poultry farms, exhibited mild to moderate level of resistance in topical (RR - 9.0 to 13.5 fold) as well as in residual contact (RR - 10.0 to 17.85 fold) bioassay methods. The house fly strains from the remaining two farms showed susceptibility to cypermethrin in both bioassays (RR < 1.0). The observations of house flies resistance in bioassay methods were confirmed by PCR-RFLP method. The phylogenetic analysis and multiple sequence alignment carried out for VSSC1 allele confirmed that, there was no kdr mutation in the para-type sodium channel gene in all the five farms studied. Similarly, the phylogenetic analysis and multiple sequence alignment of CYP6D1 revealed the absence of 15 bp insert in the 5’- flanking region indicating susceptibility to synthetic pyrethroids in the three farms in which houseflies survived at higher doses.