STUDIES OF FECUNDITY AND BEHAVIOUR OF THE ORIENTAL FRUIT MOTH, GRAPHOLITHA MOLESTA (LEPIDOPTERA: TORTRICIDAE), ON THE NIAGARA PENINSULA OF ONTARIO

Abstract

Unsprayed apple trees measurably increased the numbers of the Oriental fruit moth, Grapholitha molesta (Busck), in adjacent peach trees in only 1 of 4 years, though the apples were rather heavily infested. The moth became evenly dispersed throughout a previously uninfected peach orchard within three generations. Caged orchard trees were unsatisfactory for studying behaviour because the environment within the cages differed from that in the orchard. Experimental studies indicated that fecundity of the females was variable between years and generations and a varying proportion laid no eggs. Intraspecific competition between newly hatched larvae occurred at low egg densities; egg mortality was small but mortality of newly hatched larvae was large.