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.

Growers in IL Cautioned to Monitor for these Soybean Pests

August 14, 2020
This agronomic image shows a Miravis Top sign in Rend Lake, IL

Rend Lake, IL, Grow MoreExperience Site

Throughout the soybean growing season, our team at the Rend Lake, IL, Grow More Experience site monitors pests that are new to the area and have yield-threatening potential to help you take timely action to preserve your soybean yield potential. With soybeans at or approaching R3, it’s time to pivot from early-season scouting and prioritize managing diseases and insects that directly impact yield. At this year’s trials, we have our eye on Dectes stem borers, grape colaspis beetles and disease prevention.

Dectes Stem Borer

In the past few years, Dectes stem borer has given many growers a tough time and caused significant yield loss when left unchecked. Here’s what you need to know:

  • The larvae reside in the lower canopy, causing lodging and poor plant health, which may cause the soybean plant to snap off at harvest time.
  • The beginning stages will appear as dead trifoliate petioles and leaves.

If adult Dectes stem borers are found, growers should consider applying a fast-acting systemic insecticide to their management plan to get through the canopy and target the insect. To find damaging larvae, split the stem of an infested plant to search for a burrowed larva. At this crop stage, there are no control measures, but growers should plan for a timely harvest of affected fields.

Grape Colaspis Beetle

Another pest that has returned to our site is the grape colaspis beetle, which damages soybeans’ root systems and can transmit bean pod mottle virus. While scouting for the virus, look for yellow blotches on young leaves and in severe cases, distorted leaves. According to researchers, the virus can cause 10-60% yield loss and can’t be cured, making it critical for growers to control the pest early.

Disease Prevention

While heavy disease pressure hasn’t set in yet, now is the optimal time to apply a preventive fungicide to your soybeans. Mother Nature is unpredictable, and an application between R2 and R4 can help prevent several diseases that may crop up later in the season to threaten your yield. Even under low disease pressure, the right fungicide with proven plant-health benefits can still help boost your potential yield and profit potential.

Management Options

For efficient control of bean leaf beetles, stink bugs and other insect pests, we recommend Endigo® ZC insecticide. Containing 2 active ingredients, thiamethoxam and lambda-cyhalothrin, Endigo ZC provides broad-spectrum insect control and rapid penetration into leaves for quicker knockdown and longer residual control.

To control even the toughest soybean diseases and give your soybeans a boost with consistent plant-health benefits, consider Miravis® Top fungicide. Custom built with 2 modes of action, including Adepidyn® technology, Miravis Top delivers lasting, broad spectrum activity to keep you in control of difficult diseases.

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

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

Syngenta hereby disclaims any liability for Third Party websites referenced herein.