Predicting Colorado Potato Beetle (Leptinotarsa decemlineataSay)1Density and Potato Yield Loss2

Abstract

Third order exponential models are fit to 7 sets of Leptinotarsa decemlineata (Say) larval incidence data. A. predictor algorithm is developed to mimic density-related amplitude and shape changes in incidence curves. Potato Yield is related to area under the predictor curves by a linear equation. Use of the predictor to project the entire incidence curve based on a few early counts is limited by precision of the count data. This can be enhanced by using coefficent of variation and sample mean to determine proper sample size. Limitations of adult manipulation techniques for establishing larval density gradients are also discussed.