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MSU row crop entomologist discusses products and strategies for controlling crop pests in the coming year.

Ginger Rowsey, Senior writer

June 3, 2022

5 Min Read
Whitney Crow
Whitney Crow, assistant professor and row crop entomologist, at MSU’s Delta Research and Extension Center. Ginger Rowsey

It’s true every year is different in farming, but in the Midsouth, you can almost always count on insect pressure creating potential problems. We caught up with Whitney Crow, row crop entomologist with Mississippi State University, to discuss likely pest issues, the effect of high insecticide prices on management decisions, and how last year’s intense insect pressure led to research questions that will hopefully help growers save money and yields in the future. 

Delta Farm Press: You’ve completed the redbanded stinkbug ditch bank survey. What did it tell you? 

Whitney Crow: We found redbanded stinkbug populations north of Highway 82 relatively early in the season. Based off what we saw in the majority of the Delta, there looks to be greater potential this year to see issues with redbanded stinkbugs, especially in late-planted soybeans. 

Redbanded stink bugs are capable of causing much more damage than green, brown, or southern green stink bugs and also cause damage later in the growing season. 

There is a good correlation between what we see in the clover ditchbanks and what we see in the season, unlike a lot of insects. We’ll find plant bugs in ditchbanks early, but that doesn’t necessarily mean they’re going to be a huge issue later in the season. Planting date is really the best thing you can do to manage redbanded stinkbugs. If you weren’t able to plant early, be prepared to monitor and treat through R7. 

Redbanded Stinkbug

DFP: What type of insect pest calls have you received already this season? 

Crow: I’ve received several thrips calls already. Mostly from growers wanting to know the best product to effectively manage thrips. All winter we have encouraged growers to be mindful of using acephate for thrips. Yes, it’s less expensive than other products, but we’re starting to see a decline in efficacy with acephate. Based on research done here at the University of Tennessee, acephate is only providing about 75% control of thrips populations. We’re recommending growers transition to a product like Intrepid Edge. 

DFP: With farm chemical costs increasing so dramatically over the past year, should growers consider changes to their insect management strategies in 2022? 

Crow: We’ll have to be more mindful of our input costs as a whole. And you may have to be willing to move to a “Plan B” if products become hard to find or prices continue to go up. Our established thresholds serve as a guideline for management decisions but in a year like this we have to be especially mindful of the economic potential of the insects we’re dealing with. Be sure to take structured insect counts before making an insect management decision. Especially toward the end of the season, sometimes we put out insecticide applications that aren’t necessarily warranted. 

Each insecticide application decision should be weighted by a variety of factors such as crop value, effectiveness of the treatment available and management cost. Management guidelines are simply guidelines, and every situation is different, but the end goal never changes. We want growers to make economically sound decisions for their crop situation. But I think going into this season with the unknowns of demand and price ceilings that we’re going to have to consider alternatives to what we are normally relying on. 

DFP: Last year was a horrible year for insect pressure here in the Midsouth. What lessons did you take away from 2021? 

Crow: When I think back on the huge migrating populations of plant bugs and all the armyworm issues that came later, I would probably rank 2021 as one of the worst years for crop pests that I’ve witnessed in my career. It provided us with questions that we can hopefully address in our research program. 

Tarnished-plant-bug

One of the questions that arose during that huge migration of plant bugs is does it matter if we use a really effective insecticide versus a more cost efficient one in our early applications? Because often during those early those applications, plant bugs are migrating in constantly, so when you make an application and go back out there, there’s a chance there will still be adults in the field, but they’re not the same ones you sampled before. 

We have a graduate student who is going to be looking at insecticide applications early season to see if it matters if we use something like imadicloprid which is cheap, but only provides 30-50% control of plant bugs, versus Transform which is our best product on the market. The goal is to determine what the best prebloom management of adult tarnished plant bugs is to maintain 80% square retention. We will also be doing this in ThryvOn and non-ThryvOn, because we’ve noticed while there is no adult activity in ThryvOn, that square retention does tend to be a little bit higher, even when adults are migrating in. 

Another question we’re hoping to address is the sliding threshold for plant bugs later in the season. We know the most critical window is about the second to fourth week of bloom. In a lot of areas after that fourth week we can make some adjustments. In areas of heavy pressure, we know it’s probably a little later than the fourth week, closer to the fifth, but we can’t really nail down where we can address that threshold. So, we’re going to be looking at fruit removal at the fourth through sixth weeks of bloom to see if we can nail down the exact time we can alter thresholds without hurting yield so we can hopefully lessen our insecticide applications later in the season. 

DFP: Any parting advice for insect management for the 2022 season? 

Crow: It’s impossible to predict the intensity of insect pressure from year to year. Scouting and monitoring insect populations are always the first step. 

Crow and other MSU specialists are hosting three Agronomic Scout Schools in June. More information is available at the Mississippi Crop Situation blog

About the Author(s)

Ginger Rowsey

Senior writer

Ginger Rowsey joined Farm Press in 2020, bringing more than a decade of experience in agricultural communications. Her previous experiences include working in marketing and communications with the University of Tennessee Institute of Agriculture. She also worked as a local television news anchor with the ABC affiliate in Jackson, Tennessee.

Rowsey grew up on a small beef cattle farm in Lebanon, Tennessee. She holds a degree in Communications from Middle Tennessee State University and an MBA from the University of Tennessee at Martin. She now resides in West Tennessee with her husband and two daughters.

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