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CRW Risk Survey

Cooperative Survey of Corn Rootworm Populations in Minnesota

Situation: The MDA has been conducting an annual survey of corn rootworm populations in Minnesota since 1978. Facing growing demands for surveys of other late summer pests (soybean aphid, soybean rust) and budget/personnel reductions, the MDA decided to abandon the corn rootworm survey in 2009. Unfortunately these changes could not have come at a worse time; leaving us blind to how corn rootworm populations might be responding to rapidly increasing acreage of Bt-RW corn or how the extended diapause situation might be changing.

Project Description: Facing loss of corn rootworm data, , seed company agronomists, dealers and crop consultants have expressed an interest in contributing private data into a cooperative network that could match or exceed the quality of the previous survey in its geographical and seasonal intensity. The University of Minnesota Extension is willing to host a corn rootworm survey network combining data from both private and public sources. Preliminary work has been completed on survey procedure, data forms, and an outline of web page content. A panel representing private data sources (MCGA, seed companies, dealers, crop consultants) and public sources (Extension, MDA), will meet to finalize survey procedure, specify data input needs, and desired web outputs. Participation of ag professionals and farmers would be solicited via MCGA, winter extension meetings, MN Crop eNews, and company networks. Extension personnel would help flush out gaps in the geographical distribution.

After planting, volunteers would work with farmers to identify survey fields and areas of both Bt-RW and refuge corn for monitoring. Data from research trials on timing of corn rootworm beetle emergence from refuge and Bt-RW corn would be analyzed to predict optimal timing of survey efforts. Data would be entered online, faxed or e-mailed to the U of MN for data entry. Results would be available on a corn rootworm web site and shared with MCGA, MDA, U of MN extension, and participating companies and volunteers. Next fall, the panel would re-convene to review the project, suggest revisions in survey procedure, data handling or web access. These sites would be supplemented by plots at Research and Outreach Centers where multiple maturities and planting dates would be assessed.

Expected Outcomes:

  • With public resources likely to decline in the current economic situation, this cooperative network could re-establish a viable corn survey of corn rootworm.
  • Unlike previous surveys, data would be generated for both Bt-RW and refuge corn.
  • Repetition over years will generate a risk map.
  • Potential long-term benefits include tracking changes in risk over time, documenting area-wide impacts of Bt-RW, and potentially even indicating geographical extent of resistance problems.

Funding and Logistical Support:
This research is funded by the Minnesota Corn Research and Promotion Council. A special “Thank you!” to participating farmers, seed dealers, agronomists, crop consultants, and extension educators.

Kenneth Ostlie
Professor and Extension Entomologist
University of Minnesota
Department of Entomology
1980 Folwell Ave., Rm. 219
St. Paul, MN 55108-6125
Cell: (612) 750-0993
Office: (612) 624-7436
Fax: (612) 625-5299
Email questions on corn rootworm