You may recall seeing yellow or orange sticky traps in soybean fields here and there in August. Should there be traps in your soybean fields this year? Experts explain that the traps aren’t to protect soybeans. Instead, they’re trapping corn rootworm beetles to determine if insect protection will be needed if that field goes to corn in 2023.

Several Indiana certified crop advisers provide input on this topic:

Betsy Bower, agronomist with Ceres Solutions, Lafayette. Are first-year corn rootworms common in your area? Are you currently purchasing corn with Bt traits that control corn rootworm? If you are, it doesn’t matter what sticky traps uncover.

If you’re not using Bt corn that controls corn rootworm and you’re in a first-year corn rootworm area, having a consultant put sticky traps in fields could help you get a feel for beetle presence and know if an insecticide is needed next year.

How much is at stake? For each node of roots corn rootworms eat, expect a 15% yield loss. On 220-bushel-per-acre corn, a 15% yield loss is around 33 bushels per acre. At $7 per bushel, that’s over $230 per acre in potential loss.

Greg Kneubuhler, crop consultant, G&K Concepts Inc., Harlan. Sticky traps can be a lead indicator of potential rootworm pressure. There is a certain protocol for setting up traps. If protocols aren’t followed, it’s not worth your time.

If corn rootworm is suspected, traps are a rather low-cost method of making informed decisions for next year. Allowing your crop consultant to monitor them is a good approach. They normally have traps in other places, allowing for a good comparison to see how you stack up to neighboring areas.

An ounce of prevention is worth a pound of cure. If you pay a small fee to your crop consultant, it could be worth thousands of dollars to your bottom line if you know you need to manage corn rootworm. Historically, corn rootworm pressure was falling off, but we’re slowly seeing pockets coming back.

Bryan Overstreet, Jasper County Extension ag educator. How much it is worth? Minimum value would be cost of the insecticide treatment. But the value could be much more if you do not apply an insecticide next year for first-year corn, and have an infestation of rootworms with damage. Look at the risk associated with corn rootworm in your area. For the past few years, the risk has been lower for most of Indiana, but a few areas have seen damage.

Shaun Casteel, Purdue University soybean specialist, and John Obermeyer, Purdue entomologist. It’s labor-intensive to accurately monitor rootworm activity. A single trap on the edge of the field checked occasionally will not cut it. To be done right, five to 10 traps should be set up in a line and checked weekly for 30- to 100-acre fields.

Here’s another option. Sweep the upper canopy of soybeans a few times from late July through August. You or your crop consultant would then have a good sense of rootworm beetle presence. Even though it’s still labor-intensive, you will have eyes on your soybeans a couple of more times to address current issues like diseases. If corn rootworm beetle numbers are down, there’s opportunity to forgo a rootworm Bt trait or traditional soil insecticide in 2023.