The effect of hybridization on the periodicity of sex pheromone release of Euxoa species (Lepidoptera: Noctuidae)

ABSTRACT. The periodicities of sex pheromone release by reciprocal F₁ hybrid females obtained from laboratory matings between Euxoa declarata (Walker) and E. rockburnei Hardwick were found to be dependent upon the parental cross. The period of sex pheromone release by females from the E. declarata (female) × E. rockburnei (male) cross paralleled that of the maternal parent species, E. declarata. However, female hybrid E. rockburnei (female) × E. declarata (male) had a prolonged calling period which intersected the pheromone release periods of both parental species and peaked later than that of E. declarata. These results indicate that the circadian periodicity of calling in these species is controlled by autosomal genes and a matroklinal inheritance factor.