Co-selection and replacement of resistance alleles to Lysinibacillus sphaericus in a Culex quinquefasciatus colony.

The Cqm1 α-glucosidase, expressed within the midgut of Culex quinquefasciatus mosquito larvae, is the receptor for the Binary toxin (Bin) from the entomopathogen Lysinibacillus sphaericus. Mutations of the Cqm1 α-glucosidase gene cause high resistance levels to this bacterium in both field and laboratory populations, and a previously described allele, cqm1REC, was found to be associated with a laboratory-resistant colony (R2362). This study described the identification of a novel resistance allele, cqm1REC-2, that was co-selected with cqm1REC within the R2362 colony.

Biological fitness of a Culex quinquefasciatus population and its resistance to Bacillus sphaericus.

Biological fitness components of a field-collected colony of Culex quinquefasciatus Say that was highly resistant to Bacillus sphaericus strain 2362 (resistance ratio greater than 163,000) after 46 generations of selection were compared to those of a susceptible colony (CqSF) that had originated from the same parental cohort but that had not been exposed to B. sphaericus. The effect of B.