THE LOCATION OF EGG MASSES OF OSTRINIA-NUBILALIS [LEPIDOPTERA, PYRALIDAE] ON POTATO PLANTS

The location of egg masses of the European corn borer, Ostrinia nubila lis, was studied on potatoes (Solanum tuberosum) 'Russet Burbank' grow n on Prince Edward Island, Canada, from 1990 to 1992. The within-plant positions of 315 egg masses were characterized by the examination of approximately 3700 plants. Ninety-two percent of the egg masses were f ound on the bottom two-thirds of the plants and 95% were found on the underside of the leaflets and on the stalks. In total, 88% of the egg masses were found on the bottom two-thirds of the plants on both the s talks and the underside of the leaflets. Sampling time can be optimize d if the people engaged in scouting programs concentrate their efforts on the bottom two-thirds of the stalks alone, which represents only 3 .7% of the total surface area of the haulm but contains 50% of the egg masses.