JSM 2015 Preliminary Program

Online Program Home
My Program

Abstract Details

Activity Number: 38
Type: Contributed
Date/Time: Sunday, August 9, 2015 : 2:00 PM to 3:50 PM
Sponsor: Biometrics Section
Abstract #315697 View Presentation
Title: Nonlinear Time Series Analysis of Aphid Dynamics
Author(s): Bahman Shafii and John Merickel*
Companies: University of Idaho and University of Idaho
Keywords: Nonlinear Growth Model ; Wheat Aphid ; Autocorrelation
Abstract:

Nonlinear regression is a powerful tool that can be used in many different ecological applications to make predictions and provide inferences on relevant population parameters. In this study, a nonlinear logistic growth function was utilized to model the cumulative aphid count data over time. The model was parameterized to provide inference on three relevant characteristics, onset of aphid accumulation, the rate of increase in aphid accumulation, and the maximum cumulative aphid count. A clustering algorithm was employed to group the data into similar environments. Incorporation of a dummy variable for environments allowed for the comparison of environments via likelihood ratio tests. To account for potential autocorrelation, an autoregressive structure was incorporated into the maximum cumulative count parameter. Predicted models were validated both externally, using independent data, and internally, using bootstrap simulation of the residuals. Applications are demonstrated using 17 years of wheat aphid suction trap data for four species across 12 locations in Idaho.


Authors who are presenting talks have a * after their name.

Back to the full JSM 2015 program





For program information, contact the JSM Registration Department or phone (888) 231-3473.

For Professional Development information, contact the Education Department.

The views expressed here are those of the individual authors and not necessarily those of the JSM sponsors, their officers, or their staff.

2015 JSM Online Program Home