THE AGE OF FEMALE EUROPEAN CORN BORER MOTHS, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), IN THE FIELD AND TESTS OF ITS USE IN FORECASTING DAMAGE TO GREEN PEPPERS

Abstract

AbstractThe mean post-mating age of mated female moths of the European corn borer, Ostrinia nubilalis (Hübner), from light traps varied from 3.4 to 5.2 days during the June–September flight period at Harrow, Ontario, in a manner consistent with assignment of moths to 3 generations per year. At the beginning of the first generation the mean age was 3.66 days and rose to 5.21 before flights ceased. At the beginning of the second generation the mean age was 3.39 days and rose to 4.47 days. A third generation could be detected in early September by a significant drop in age and an increase in virgin females. The average age of mated females was negatively correlated with the proportion of virgin females in the same week (r = −0.648, P = 0.02), indicating that about 40% of the variance in age of mated females was associated with emergence of new recruits to the population. Females collected with a sweep net from their day time resting places in weeds were either the same age or older than those from the light trap. The mean age of moths from light traps was found to be not meaningful when it was tested as a factor in forecasting damage caused by their progeny in green peppers 3–5 weeks later.