Database Research Summaries
2018 Evaluating sample-unit size for estimating stink bug abundance on soybean

calendar_today Year of Research: 2018
update Posted On: 12/04/2019
group Christina DiFonzo (Principal Investigator, Michigan State University)
bookmark Michigan Soybean Promotion Committee

Research Focus

The focus of this project is to research stinkbugs and their movement into northern soybean fields.


  • Contribute Michigan data to a larger, region-wide effort to determine the optimal number sample size needed to estimate stink bug numbers in soybean. ‘Optimal’ will be determined by comparing the current sampling plan (sets of 25 sweeps) with a reduced plan (sets of 10 sweeps) in:
    • Effectiveness – number and species of stinkbugs collected.
    • Precision – variation in the sets of samples.
    • Cost – time spent walking through a field and sweep sampling.


  1. Sample units to estimate stink bug numbers in soy-seven locations have been sampled weekly since early July 2018. These locations intentionally vary in planting date, field size and the surrounding landscape. Each week, 15 sets of paired samples are taken in a zig-zag pattern across the field. The samples are bagged, frozen and later sorted to count and save stinkbugs adults & nymphs. After sorting, all samples eventually are sent to the University of Minnesota for stinkbug ID to species and analysis of data from the nine states.
  2. In six of seven fields, taking smaller sets of 10 sweeps gave the same estimate of stinkbug abundance as taking sets of 25 sweeps. The only exception was a field on the MSU campus, which was much smaller in size than the commercial fields. This data was provided to the University of Minnesota, which is pooling and analyzing it with similar data from other states.
  3. Two fields in Clinton County west of St. Johns, exceeded the threshold for stinkbugs.


  • Research-based information on the stinkbug species currently, and their movement into, Midwest soybean fields and will be distributed via the extension system.
  • This research will provide a plan to combat and fight future stinkbug issues.
  • A Midwest stinkbug identification guide will be created and distributed at extension meetings in conjunction with research findings.

For more information about this research project, please visit the National Soybean Checkoff Research Database.

Funded in part by the soybean checkoff.