Ask the Agronomist: Corn Rootworm

Thanks for tuning into Week 12 of our “Ask the Agronomist” Audiocasts. Guest Agronomist and Latham Hi-Tech Seeds Regional Sales Manager for Eastern Iowa, Jerry Broders, is filling in for Latham’s Senior Agronomist, Mark Grundmeier. To listen to Jerry’s response to this week’s question about Corn Rootworm, play the audio file below.


Listen to this week’s Ask the Agronomist to learn about effective strategies for fighting Corn Rootworm.

Q: We’ve gotten some damage from Northern Corn Rootworm. What else are you seeing out in the fields across your territory?

A: Western and Northern Corn Rootworm are common insects that are well versed in overcoming control practices. That’s why we recommend farmers scout all fields for corn rootworm. Northern Corn Rootworm feeds on corn silks, but Western Corn Rootworm can feed on leaves, too.

The wide range in planting dates this spring creates a perfect opportunity for rootworm beetles to move between fields. A late-maturing corn field may attract a large number of beetles if neighboring corn has stopped producing pollen.  Beetles may also move into corn and/or soybean fields that have an abundance of pollen-producing weeds, including volunteer corn, ragweed or foxtails.

Q: What type of damage should farmers look for?

A: Corn rootworm larvae feed on roots. Check fields for lodged plants, especially now that storms might be affecting stands. However, don’t assume lodging is a result of corn rootworm as compaction from planting into wet soils can cause poor stands.

Preventative maintenance needs to be done to reduce risk for next year’s crop. Especially in corn-on-corn fields, spray insecticide to rid the field of any larvae that may have been laid. Also make sure that fields with corn rootworm problems this year get traited corn next year that protects against corn rootworm. Latham Hi-Tech Seeds has hybrids referred to as Gladiator™ hybrids that have undergone rigorous testing to ensure they perform well under intense corn rootworm pressure.

Q: With a name like Gladiator, it sounds like we’re declaring war on insects! What “weapons” make these hybrids effective against insects?

A: Latham has a full lineup of products ranging from 92 day to 114 day maturities.  We use Genuity® SmartStax® products, as well as Syngenta’s Agrisure 3122 since these contain two modes of action for below-ground insects.  In addition, we are eagerly waiting for full approval of Syngenta’s new Duracade double rootworm trait that looks very promising.

If you have a question about what you’re seeing in the fields, feel free to ask! Send your questions via Twitter to @LathamSeeds, in a private message on Facebook or call our office at 1-877-GO-LATHAM (1.877.465.2842).

Also be sure to check out for timely agronomic information. Crop reports from specific areas across Latham’s six-state marketing area are published every Wednesday during the growing season by Latham’s regional sales managers in each of those locations. New articles are posted each week day on our blog. You can even search for “topics” by simply typing key words into the search bar on the upper right-hand corner.

Thanks for tuning in to this week’s Ask the Agronomist. We’ll be back again next week to field all of your questions during #grow16.