Side effects of insecticidal usage in rice farming system on the non-target house fly Musca domestica in Punjab, Pakistan.

Insecticidal usage in the rice farming system may affect non-target insect species present in the same fields. Musca domestica, a well-known pest of medical and veterinary importance worldwide, is one of the important non-target insect species present in the rice farming system. In this study, five strains of M. domestica were exclusively collected from rice fields in major rice cultivated areas of Punjab, Pakistan, and evaluated for the presence of insecticide resistance against nine commonly used insecticides in the rice farming system. Moreover, the performance of life-history traits was also studied. Compared with a Lab-susceptible reference strain of M. domestica, all the field strains exhibited moderate levels of resistance to carbofuran (RRs = 27.96-46.00 fold) and cartap hydrochloride (RRs = 31.48-48.21 fold), low to moderate levels of resistance to gamma-cyhalothrin (RRs = 19.00-43.00 fold), chlorantraniliprole (RRs = 11.90-27.10 fold), monomehypo (RRs = 14.38-25.84 fold), and fipronil (RRs = 13.23-40.15 fold), low levels of resistance to triazophos (RRs = 11.13-19.83 fold), and very low to low levels of resistance (RRs = 7.83-13.28 fold) to flonicamid. The performance of life-history traits (developmental time, adult eclosion rate, fecundity, egg hatch rate, and longevity of adults) of field strains was weaker as compared with that of the Lab-susceptible strain. These results contribute to the growing knowledge on the effects of insecticidal usage in agriculture on non-target invertebrates, and necessitate the need to explore alternate insecticides that can effectively control insect pests but safe for non-target organisms.