Insects

If you have found yourself dealing with alfalfa weevil more often in the last few years, you are not alone. Reports of large populations and control failures have seemingly increased in recent years, not just in Illinois but throughout the Midwest. Alfalfa weevil populations resistant to pyrethroid insecticides were confirmed in the western U.S. several years ago, and there are some indications we might be seeing this in the Midwest as well. In Illinois specifically, it has been several years since our management recommendations in alfalfa have been revisited – we want to make sure these recommendations reflect the current situation.…

Corn rootworm beetles will begin emerging throughout Illinois over the next couple of weeks (we noticed the first few western corn rootworm beetles of the year at our Urbana field site earlier this week). There are a number of things we can learn by keeping track of corn rootworm emergence, particularly in fields that have a history of rootworm problems:

• Control performance. Usually, our first indication that a local population is developing resistance to a Bt trait package is elevated numbers of beetles emerging from traited corn;

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