OCCURRENCE OF A TWO GENERATION STRAIN OF THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), IN QUEBEC

Abstract

AbstractThere are now two strains of the European corn borer, Ostrinia nubilalis (Hübner), in Quebec. The strain normally found produces one generation while the more recently introduced strain produces two generations per year. Both strains have been characterized and compared with corn borer strains from Ontario and New York State. The two attributes of the recently introduced strain that promote the development of a second generation are (1) early emergence in the spring with less intense diapause and (2) a lower critical photoperiod for diapause induction. The latter characteristic allows pupation of first generation larvae. Field and laboratory tests on the pheromone response of adult male moths demonstrated that the origin of this recent introduction was New York State.