Corn rootworm egg hatch is happening now

Like all insects, corn rootworm matures based on heat. Eggs overwinter and hatch into larvae based on accumulating soil degree days. We can expect about 50% of the population to hatch when 684-767 degree days are reached. Southwestern Iowa is experiencing 50% corn rootworm egg hatch right now. The rest of the state will hit that target in 7-14 depending on future temperatures.

Predicted corn rootworm egg hatch in Iowa for 2012. Click here for current degree day accumulation for corn rootworm. Map courtesy of Iowa Environmental Mesonet, ISU Department of Agronomy.

I strongly encourage you to scout for rootworm damage later this summer, especially in continuous corn fields where populations can be higher. I expect larval establishment to be high this year, so estimating root damage is important for gauging population densities. For more information on the 2012 corn rootworm egg hatch in Iowa, read this ICM News article posted today.