Cross-Resistance Spectrum of Fenitrothion-Resistant Strain of Tribolium Castaneum (Herbst)

Investigations on the cross-resistance characteristics of fenitrothion-resistant (x 26.58) strain of Tribolium castaneum (Herbst) were carried out against eight insecticides. DDT and lindane respectively, showed 3.3 and 20.0% mortality at as high a concentration as 1%, showing high degree of cross-resistance. Among organophosphates, highest resistance ratio was observed in malathion (x 5.88), followed by monocrotophos (x 5.82) and DDVP (x 3.27). The resistance ratios of synthetic pyrethroids, viz cypemethrin, fenvalerate and deltamethrin were x 10.14, x 7.42 and x 4.83, respectively. The study revealed that there is a definite presence of inter-and intra-cross-resistance spectrum of the resistant strain. It was inferred that usage of fenitrothion in storage pest management may be restricted/discouraged in view of its wide spectrum cross-resistances.