TEMPERATURE-DEPENDENT MODEL FOR PREDICTING FIELD POPULATIONS OF GREEN PEACH APHID, MYZUS PERSICAE (HOMOPTERA: APHIDIDAE)

Abstract

A temperature-dependent model for predicting green peach aphid population development in potato fields was devised and tested. A laboratory estimate of generation time was utilized to derive expected generation number from field accumulated degree days (1975–77). Different aphid populations were produced in replicated field plots (1975–77) with various application rates of the systemic insecticide, aldicarb. Density data from these plots were regressed on the expected number of generations to derive prediction equations. These equations were coupled in a Fortran computer program with a degree day algorithm. Weather forecasts, therefore, provide input for future aphid population predictions. The model is being used to evaluate various control strategies and to decide on spray dates from weather forecasts.