ECONOMIC-EFFECTS OF RESISTANCE AND WITHDRAWAL OF ORGANOPHOSPHATE PESTICIDES ON AN APPLE PRODUCTION SYSTEM

Theoretical investigations have suggested that resistance may have sev ere effects on the long-run economic performance of agricultural produ ction systems. In addition, regulatory withdrawals of critical insecti cides may hasten the development of resistance. Given the complexity o f the problem, an optimizable bioeconomic simulation was used to exami ne the economic effects associated with regulation and insecticide res istance in the mid-Atlantic apple production system. Withdrawals of si ngle organophosphates were modeled by reducing the size of a hypotheti cally complete insecticide control set. Reductions in the size of the insecticide control set led to substantial additional economic losses because of long-term resistance development. Azinphosmethyl withdrawal resulted in an additional -$1.66 billion present value loss and chlor pyrifos withdrawal an additional -$1.91 billion present value loss in economic benefits over a 25-yr period of analysis, whereas a withdrawa l of microencapsulated methyl parathion resulted in an additional -$2. 47 billion present value loss to resistance over 25 yr. Along with eco nomic effects, insecticide withdrawals also led to changes in the tota l long-run use of chemical controls, although the magnitude and direct ion of the change depended on the specific insecticide withdrawn. Over all, results of our study suggest that the effects of interactions bet ween regulation and resistance may lead to severely underestimating th e actual benefits associated with a continued chemical registration, e specially when using static budgeting analyses as is currently done in the federal regulatory assessment process.