Cross-Resistance Characteristics of Deltamethrin-Resistant Strain of Tribolium castaneum (Herbst)

The results showed that deltamethnn-resistant (x78.62) strain of T castaneum extended high degree of cross-resistance to other synthetic pyrethroids, viz., cypermethrin (x48.94), λ-cyhalothrin (x45 50) and permethnn (x58 11). However, in case of fenvalerate, cross resistance ratio could not be determined as it gave 16 6% mortality at 2% concentration The cross resistance to several organophosphorus had a varied range, malathion (x23 43), chlorpynphos (x22.45), fenitrothion (xl0.41), quinalphos (x6 17), temephos (x5.72), phosphamidon (x5 54), phorate (x4 03) and dichlorvos (x3.31). However, there was no cross-resistance between the deltamethnn-resistant strain and monocrotophos (x1.10) The resistance level of p, p’ DDT and lindane could not be determined resulting 16 6 and 20 0% mortality, respectively, at 2% The resistant strain had 6 13-fold resistant to, carbosulfan Thus, (he observed intra and inter-group cross-resistance spectrum of the resistant strain was a sequel to the selection with deltamethnn.