Development of an Improved, Integrated Management Program for the Internal Lepidoptera Pest Complex Attacking Apples in Western NY 1999
PI(s): H. Reissig, A. Agnello, J. Nyrop, Department of Entomology, NYSAES, Geneva, NY 14456
COOPERATORS: D. Breth, Area IPM Specialist, Cornell Cooperative Extension Program, J. Carroll, Fruit IPM Coordinator, Cornell University.
Type of Grant: Pheromones; biorationals; microbials; conventional pesticides
Project location(s): Results from this project can be applied throughout the Northeastern United States and also apple production regions in the midwestern United States.
Abstract: Recently, apple growers in western NY have suffered severe financial losses from unacceptable levels of fruit infestation by internal lepidoptera larvae. If this new crisis is not solved quickly, it could hasten the decline of this already beleaguered industry. Furthermore, if growers are forced to use harsh insecticides and revert to applying sprays on a calendar basis at 14-day intervals throughout the season to control these pests more than 30 years of IPM research and implementation may be subverted. The objectives of this project were : (1) Provide apple growers with effective ways of controlling internal fruit feeding Lepidoptera that are consistent with and integral to existing apple pest management systems. (2) Develop better understanding of internal Lepidoptera distribution in time and space, and susceptibility to insecticides so that control tactics can be made more robust and effective. This year's studies showed that currently available technology for timing insecticide applications against the summer generations of oriental fruit moths, developmental models based on heat unit accumulations and trap catch threshold levels are not adequate for use in NY apple orchards. Warrior, a synthetic pyrethroid insecticide, which is toxic to beneficials, was the most effective insecticide in protecting fruit, but Avaunt (Indoxacarb) provided similar levels of control. Laboratory bioassays were conducted to compare the susceptibility of field populations of oriental fruit moth in orchards in western NY to a standard organophosphate insecticide, Guthion (Azinphsomethyl) that has been widely used in the past. These studies indicated this pest has developed low levels (about 2-fold) to organophosphates. However, Imidan, another widely used standard organophosphate insecticide, provided adequate control of fruit damage from internal lepidoptera in 9 out of 10 plots in different orchards when it was applied at high rates. Mating disruption alone using sprayable formulations of oreintal fruit moth pheromones did not provide adequate control of summer damage in orchards that were subjected to high pressure from this pest. However, an integrated program utilizing sprayable pheromones and two initial applications of Avaunt provided slightly better control. Periodic sampling of fruit throughout the summer in various management programs showed that damage was very low from late July through August. Generally, higher levels of damage were observed in all plots when fruit was evaluated in mid-late October, although fruit infestation levels were generally below 2% at harvest in most of the treatments. The overall results of this study suggest that mating disruption, and standard organophosphate insecticides as well as newer selective insecticides can provide adequate control of internal lepidoptera in problem orchards in western NY. In the future, additional work should be done to determine the optimum seasonal timing of insecticides or even pheromones (particularly sprayable formulations) for management of internal lepidoptera. Different management programs including integrated programs utilizing insecticides and mating disruption that are designed to be cost effective and IPM compatible should be compared in large scale tests in grower's orchards throughout western NY. It would also be useful if practical monitoring programs for detecting fruit infestation during the season could be developed so that growers or consultants could monitor orchards periodically to determine when and if control measures are necessary. Finally, additional monitoring of susceptibility of field populations of oriental fruit moths and perhaps codling moth to commonly used classes of compounds such as organophosphates and pyrethroids should be continued. These studies are necessary to determine if there are regional patterns of susceptibility differences throughout apple production regions in western NY and to monitor any changes during the future.