Biochemical and molecular analysis of the pirimicarb effect on acetylcholinesterase resistance in Tunisian populations of potato aphid Macrosiphum euphorbiae (Hemiptera: Aphididae)

Mutation in the gene encoding the enzyme acetylcholinesterase (AChE) of the potato aphid, Macrosiphum euphorbiae, associated with resistance to a carbamate insecticide has been characterized. One point mutation producing modification in the predicted amino acid sequence of the product of the M. euphorbiae ace1 gene in resistant vs. susceptible strains has been identified. This modification occurs at one site that is identical to mutation previously described for another aphid species Aphis gossypii. The results obtained here also suggest that the widespread use of carbamate insecticides will likely lead to a predictable acquisition of resistance in wild populations of M. euphorbiae as well as other pest species. For surveys of M. euphorbiae populations that may develop resistance, diagnostic tests using PCR-RFLP based methods for detecting the presence of this mutation in individuals are described.

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► Characterization of AChE was performed by toxicity bioassays and inhibition test.
► Sequencing of AChE gene revealed a point mutation related to pirimicarb resistance.
► PCR-RFLP is a reliable technique to survey emergence of resistance in natural populations.