Due to the very wet spring and the severe storms that plagued most of the state on May 15, many fields are saturated, and large portions of some have standing water. How will these flooded conditions affect corn rootworm survival?

Many articles have been written on this topic through the years. In general, survival of corn rootworms depends on the duration of the standing water, its temperature, and the point in the season when "ponded" conditions develop.

If flooding occurs very soon after larval hatch, and before larvae can establish in root systems, a high percentage of larvae succumb to these environmental conditions. The timing of larval hatch varies considerably, but in most years it typically occurs near the end of May across central Illinois. In some years with very cool springs, hatch has occurred as late as mid-June in central Illinois (June 12, 1996; June 13, 1997).

Certainly, a late hatch that extreme has been the exception. However, the very cool spring experienced thus far may result in a delayed hatch and also occur at a point when saturated soil conditions no longer exist, improving corn rootworm survival.

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