Corn rootworm pressure is expected to be high this year, with larvae already beginning to hatch in some areas. Andrew Penney, technical agronomist for Bayer Crop Science, talks about how corn rootworm pressure is looking in the Corn Belt.
He says, 鈥淚t’s been one of those years where, with the population we saw last year and the amount of egg-laying that likely took place, factored in with the warm winter, there’s a concern with the populations and the amount of feeding that’s going to go on in a lot of these cornfields across the Corn Belt. It could be another year for higher populations. The biggest challenge, I think, is the shift we’ve had with less-susceptible populations, but also just in management tactics that we’re having to do to control these insects. Historically, we’ve been able to rely on traits. It’s coming to the point where, with these populations, we have such a wide window, whether it’s egg hatch and the larva feeding or adults emerging, the window seems like it’s gotten wider and longer.鈥
He talks about the actions farmers can take right now, especially in that cornfield that鈥檚 coming off soybeans in 2023. Penney says, 鈥淭he best thing we can be doing right now is, if you’re in the area where you think you might have extended diapause, be looking for some first-year corn coming off soybeans. Be looking for some lodged corn. If you’re in that continuous corn scenario, go out and dig roots. That’s the best thing we can do right now. Go and dig roots, see if there’s any feeding, and then once we get past this stage, as we approach tassel and then the silks are out, go out in the field when the silks are out, and look for adult beetles feeding on those silks. That’s going to give you a good indication of a rough estimate for the amount of eggs that are gonna get laid, which will impact next year. Whether you’re in that area where you deal with extended diapause or the western corn rootworm variant origin area that’s always had higher populations because of corn on corn, just go out there this time of year, dig some roots, and look for larvae. and then wait for the silks to come out and look for adult beetles.鈥
Penney reminds corn growers that they can join Bayer鈥檚 free agronomic program, The Watch, which leads the way in providing guidance on how to gauge rootworm pressure.
He says, 鈥淭he main objective of this is to help growers understand that there is kind of a shift in how we have to manage corn rootworm, going out and looking for corn rootworm, digging plants, looking for feeding on those roots, looking for the scarring, and then again going out and looking for adult beetles during silking. It’s helping growers become aware that we can no longer just assume that traits are 100 percent effective. Although we have the best traits on the market and technology to help with that, we still need to monitor the efficacy of these traits and also monitor populations. If Mother Nature always finds a way, and if they found a way to adapt through rotation, then the more we know about scouting procedures and understanding the management that helps control these insects, the better off our growers will be.鈥
Penney says The Watch is offering FREE Corn Rootworm Pressure Starter Kits to farmers who sign up for the program by July 16 – and the kit includes several sticky traps.
He says, 鈥淪ticky traps help us get a good feel for the populations within that area. So, putting those out is just a good quick way, and then checking them in a few days is a really good way to help the grower understand what the population number they’re dealing with is in that field. The best management practice that growers can do is rotation. If you’re in a situation where you have high populations, rotation is always going to be the best management practice. But if you’re in that situation where you’re scouting and understanding the populations in a few years, corn on corn, we have the best trait on the market that can help control corn rootworms in RNAi technology. Combining that and using that with our SmartStaxPRO with RNAi Technology and VT4PRO with RNAi Technology trait systems. They’re highly effective on corn rootworm.鈥
Again, now is the time to be proactive to protect your fields 鈥 and yields 鈥 from corn rootworm next year. Visit to join The Watch and request your FREE Corn Rootworm Pressure Starter Kit by the sign-up deadline on July 16.
