New York State Flower Industries , Inc
In the Rose Manual Floyd Smith considers the omnivorous leaf roller, Platynota stultana, as the major leaf roller pest of greenhouse roses. It is now widely distributed and a common problem in New York State. Unfortunately, the omnivorous leaf roller has survived the applications of insecticides that have eliminated, or reduced, other leaf roller species affecting roses. This insect causes so many problems and losses to rose growers throughout the year that its life history and control will be discussed in this article. Description and life cycle: The adult leaf rollers are variably colored light and dusky shades of brown. They are active from twilight to dawn and rest during the day. During the night females lay eggs on the upper surface of the rose leaf in flat clusters that contain from 20 to 100 or more eggs. The pale green eggs are cemented together in an overlapping, shingle-like manner. The average female lays about 300 eggs, but some may lay over 500. Larvae hatch after about nine days at 70°F and often most of the larvae in one cluster will appear within a few minutes of each other. The newly hatched larvae are only about y10 inch long, but they manage to scatter in all directions to find separate, narrow crevices in tender leaf or bud tissues where they begin feeding. After four to six days they have matured sufficiently to web together, or roll, several leaflets into a 'nest' in which they feed. It is the period from hatch to formation of the 'nest' that the larva is most vulnerable to insecticidal control.
Keywords: Omnivorous leaf roller Insecticides Platynota stultana rose growers Lay eggs hatch