A new tool to help with insect management
May 5, 2006 - Author: Jill O’Donnell, MIchigan State University Extension
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
We have a new tool at the IPM Resources web site available to help you with your insect pest management. Christmas tree resources are being built at: http://www.ipm.msu.edu/christmastree.htm
Landscape and nursery resources are being built at: http://www.ipm.msu.edu/landscape.htm
Last fall, Nathan Siegert, Dr. Deborah McCullough and Dr. Jeffrey Andresen generated maps of average seasonal degree day accumulations for Michigan and surrounding areas. They did this by acquiring the daily weather records of maximum and minimum air temperature collected from 1971-2000 (30 years) at 92 weather stations in Michigan and areas of Wisconsin, Illinois, Indiana and Ohio (Midwestern Regional Climate Center, 2005). Weather stations were selected based on the reliability of their long-term weather data and their relative location, to ensure adequate representation of the climatic variability of the region. Using these daily weather records, they calculated the average seasonal accumulation of growing degree day units over the 30-year period for each location and then calculated degree day with a base temperature of 50 °F. Then separate GIS contour maps were generated for the average seasonal accumulations of 50 to 2000 degree days (base 50 °F) throughout the region, at 50 degree day intervals.
To use this web site, you will select a pest of interest. In some cases, you will also need to select the life stage or tree of interest. That will bring up the appropriate degree day map. Then you can simply find the location of your property and use the map legend to determine when that degree day accumulation is likely to occur. Remember, these maps are a useful tool to help you plan your pest management program, but don’t replace good scouting or surveys.