Backcrosses performed with the E and Z strains from France and from the USA.

aObtained from female Z×male E crosses. bObtained from a female E×male Z cross. cDue either to a poor extraction of the pheromone compounds or to an insufficient quality of the chromatograms. dp-values of two-tailed binomial tests comparing the observed proportions of E:H and Z:H pheromone types within each line with the 50∶50 expected under the assumption that pheromone types are determined by Pher, an autosomal locus with two codominant alleles: PherE and Phez[22], [24].