Thanks for signing up!

Look for the Digest in your email twice a month.

Follow Us

Sign up for our Digest to receive the latest agronomic insights and crop management advice for your primary growing region delivered twice a month to your inbox.

Corn Rootworm Adult Beetles On The Rise in IA

April 4, 2018
This agronomic photo shows corn rootworm.

After several years of low corn rootworm pressure (CRW), populations of this insect may be on the rise in Iowa. Data collected in October by the Iowa Soybean Association On-Farm Network reports an uptick in the number of both the Northern and Western corn rootworm adult beetles in corn fields across the state. The most severe infestations scouted were also in the driest areas so a high rate of larval survival was likely a factor.

The charts below show the corn rootworm population per trap per day:

This data chart shows the corn rootworm populations per trap per day in Iowa. This data chart shows specifically the Northern corn rootworm populations per trap per day in Iowa.

The 3 species to look out for are Western, Northern, and Southern CRW beetles. Some things to keep in mind about this insect include:

  • Eggs are laid in mid-to-late summer and overwinter
  • Eggs hatch from mid-May to early June
  • Larvae start feeding within 3-4 hours of hatching

This agronomic image shows Western, Northern and Southern corn rootworm.

       Larvae stage                              Western                  Northern                 Southern

With an increased number of beetles spotted in October 2017, what does this mean for the 2018 season? While factors like temperature and weather can affect the larval survival rate, it is still important to recognize the rising population and prepare accordingly. We suggest an insecticide like Force® Evo or Force® 3G that helps protect developing corn root systems against insects. For more information, please contact your local Syngenta Sales Representative.

Sign up for the Know More, Grow More Digest to receive twice-monthly agronomic e-mail updates pertinent to your area.

All photos are either the property of Syngenta or are used with permission.

Syngenta hereby disclaims liability for third-party websites.