Insecticide resistance management and integrated mite management in orchards: Can they coexist

At the core of an integrated pest management program for Pennsylvanian apple orchards is an integrated mite management program that is based on a natural enemy, the coccinellid Stethorus punctum punctum (LeConte). The program relies upon the principles of ecological selectivity (e.g. chemical selection, timing, dose and method of application) for the organophosphate and carbamate insecticides. During the last 20 years the tufted apple bud moth (TABM), Platynota idaeusalis (Walker), a direct pest of apple, has developed resistance to these two chemical classes. In an effort to address this growing resistance problem, an intensive research program was initiated in 1986 on how to manage insecticide resistance in TABM while preserving the integrity of the integrated mite management program. One aspect of this research program is the investigation of biochemical and genetic approaches to resistance, including an analysis of detoxification mechanisms, effects of host plant allelochemistry on resistance and detoxification enzyme activities, reversion, gene flow and the isolation and characterization of a gene for glutathione transferase from TABM. Management approaches that have been developed and successfully implemented include pheromone mating disruption, parasitoids, ground-cover management including insecticides, Bacillus thuringiensis Berl. products and insect growth regulators. Resistance management options for TABM are presented.