Influence of cultivar and plant age on European corn borer (Lepidoptera: Pyralidae) infestation in snap beans [Ostrinia nubilalis, Phaseolus vulgaris]

Nineteen cultivars of snap bean and wax bean, Phaseolus vulgaris were uniformly infested with egg masses of European corn borer, Ostrinia nubilalis . A 5-fold difference in number of tunnels was found on the various cultivars. Cultivars differed in whether pod injuries or stem injuries predominated. Pod tunneling was most common on "Gold Crop" and "Pillsbury 516" and least common on "Sungold". Varietal differences in susceptibility to stem tunneling varied with plant age at time of infestation. Larval survival appeared to increase with age of the host plant at the time of egg hatch. Adult moths confined on four cultivars showed no ovipositional preferences. Newly hatched larvae bored into stems within 4 days, but were not found in the pods in the first 10 days.