Transect Sampling to Enhance Efficiency of Corn Rootworm Monitoring

Abstract

Crop monitoring for corn rootworm remains the best means to assess fields at risk from this pest if replanted to corn the following year. Improvements in sampling methodology have reduced the minimum sampling time required to make a management decision to about 20 minutes or less per field per visit to make a management decision. Many growers still find this time commitment a constraint to weekly scouting. The current sampling scheme involves covering most of the field following a "W" pattern. The goal of this project was to assess the feasibility of replacing this current sampling pattern with a simpler and less time-consuming transect (straight line) pattern. Our computer simulations demonstrate that treatment decisions based on transect sampling would have an acceptably low error rate (< 0.05) over a wide range of realistic rootworm densities and spatial dispersion patterns. Further research will be necessary to determine how likely rootworm populations are to fall within this range.