Supplement 1. R source code for the spatial modeling package described in this paper, including main and subroutine files, with descriptions of code and instructions for use.

File List Kernels.R SpatialParams.R SpatialSubs.R Example.R Description This supplement includes the subroutines and an example main file to be used for performing spatial simulations as described in O’Rourke and Jones (2011). It was written on a Macintosh computer running Mac OS X 10.6.7 (10J869), originally coded in R 1.8, and updated for publication to R version 2.13.0. i. Kernels.R: This is an R script containing descriptions of dispersal kernels used in our simulations. Currently included are a uniform dispersal kernel and a quereshi kernel (reference). ii. SpatialParams.R: This file contains basic parameters for the landscape including dimension, percentages of agricultural land, agricultural land devoted to corn production, and non-agricultural land; parameters for crop rotation and finally, the number of seasons (years) a given landscape will be simulated. iii. SpatialSubs.R: This file contains subroutines for creating the landscape, for insect dispersal and population growth. iv. Example.R: An example simulation. This file calls the appropriate subroutines and runs an example simulation for nyears seasons. Plots the results as a time series.