D3350: Development of alpha-cypermethrin resistance and cross resistance pattern in a field strain of Musca domestica L.

Musca domestica L. is a cosmopolitan and deadliest pest of human and livestock. It also serves as vector of many pathogens which cause serious diseases to livestock. This vector pest requires effective insecticide resistance management programs (IRM) worldwide including Saudi Arabia. But, the development of insecticide resistance in this pest is alarming issue. The present work explores the development of alpha-cypermethrin resistance and cross resistance (CR) to fourteen insecticides in an alpha-cypermethrin selected strain (Alpha-Sel) screened for 24 generations. Results showed that the resistance to alpha-cypermethrin increased from 46.92-fold (G₅) to 479.57 (G₂₄) in the Alpha-Sel females and 41.09-fold (G₅) to 253.72-fold (G₂₄) in the Alpha-Sel males compared to the susceptible strain (SS). The Alpha-Sel M. domestica displayed moderate CR between alpha-cypermethrin and bifenthrin (15.47-fold), deltamethrin (28.38-fold) or cyfluthrin (16.77-fold), low CR between alpha-cypermethrin and cypermethrin (5.02-fold), fenitrothion (6.14-fold), chlorpyrifos (4.77-fold), malathion (2.05-fold), diazinon (8.05-fold), pirimiphos-methyl (2.16-fold), triflumuron (3.29-fold) or pyriproxyfen (5.00-fold), and no CR between alpha-cypermethrin and diflubenzuron (1.27-fold), cyromazine (1.93-fold) or methoxyfenozide (1.15-fold) in comparison with the SS. In conclusion, no or low CR reveals possibility for successful management of alpha-cypermethrin resistance with rotational usage of these insecticides for control of public health pest, M. domestica.