No. 1 Article 3/March 19, 2009

Early-Season Insect Activity

Not much is happening yet on the insect front, but it won't be long before activity begins and then accelerates as temperatures warm up and weather fronts aid some insects' journeys to Illinois. We have already received our first report of black cutworm adults being captured in a pheromone trap. Alan Mosler, Effingham-Clay Service Company, reports that he captured two black cutworm moths in a pheromone trap in Marion County on March 10. Although not "intense captures" (9 or more moths captured over 1 or 2 days), these first captures signal the arrival of some moths that might produce larvae that will threaten corn seedlings when they emerge. You can keep track of the progress of black cutworms at the Illinois State Water Survey WARM (Water and Atmospheric Resources Monitoring) Pest Degree Days Web site. You can click on "Calculator" or "Maps" to generate the desired information for specific insect pests and locations. By following the string of information, you can also learn about the relationship between accumulated degree days and insect development.

For example, if you want to determine the status of alfalfa weevil activity at a specific Illinois location, go to "Maps", click on 48° (Alfalfa Weevil), "Current Total," and "Display Map" to generate a map that shows degree day accumulations based on information from the stations in the Climate Network. You can also determine "One-Week Projections" and "Two-Week Projections" that will give you some idea about what to expect in the near future. As of March 17, 200 degree days above the base temperature of 48 °F had accumulated in Jackson, Monroe, Perry, Randolph, and St. Clair counties. Alfalfa weevil larvae will begin to hatch when 300 degree days accumulate.

We'll keep you posted as insect activity escalates, but you can get the specific information you need by checking on insect development in your area. So, let the insect fun begin!--Kevin Steffey

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