Diversity and distribution of Mdace mutations involved in propoxur resistance in the house fly (Musca domestica L.) in China

BACKGROUND

The house fly is a public health pest due to its ability to transmit various pathogens worldwide. The suppression of house flies is frequently controlled by organophosphate and carbamate insecticides, but recurrent selection has led to the mutated target. To understand the spread and evolution of Mdace mutations in house flies, we sampled flies in eight different China provinces, sequenced, and then estimated the frequencies of mutations.

RESULTS

The inhibition of AChE towards propoxur varied geographically and was lowest in the Heilongjiang field population, and highest in Jiangsu population. The overall frequencies of the different Mdace mutations (V260L, G342A, G342V, F407Y) varied considerably between populations. Strong positive correlations were found between acetylcholinesterase (AChE) insensitivity and the frequencies of G342V allele, 342A/V genotype and combination (260V/L-342A/V-407Y/Y) for the field populations. Eighteen combinations of Mdace at three sites (V260L, G342A/V, F407Y) were observed, with the majority of flies being categorized into the combination (260V/L-342A/V-407Y/Y), ranging in frequency from 24% (in field populations in Hubei and Hainan) to 96% (Jiangsu).

CONCLUSION

Based on comparison with historical data, the mutations responsible for the extremely high resistance to the level of insecticide resistance spread widely, propoxur should be limited to use for house fly control in China. © 2024 Society of Chemical Industry.