Laboratory Hybridization and Mating Period Studies Using Two Pheromone Strains of Ostrinia nubilalis1,2

Strong laboratory reproductive isolation exists between 2 strains of Ostrinia nubilalis (Hübner). This reproductive isolation is related to the use of different sex pheromones by the 2 strains, and differences in mating periodicity. Hybrid progeny, when produced, exhibit heterosis, but no great genetic deficiencies are observed when the hybrids are inbred. Thus the 2 strains appear to possess the same basic genetic systems, with enough variation introduced through hybridization to cause hybrid heterosis.