Corn rootworm control: Syngenta to offer insecticide in 2026

MALTA, Ill. — Farmers will have a new option for controlling corn rootworms with Syngenta’s Opello insecticide.

“We expect registration of Opello in September 2025 and selling it for the 2026 growing season,” said Kevin Langdon, technical product lead for Syngenta.

Over 12 years of research have gone into the development of the soil-applied insecticide that has been tested in more than 3,200 trials in the United States.

“Through the development of the Plinazolin technology we spelled out the parameters that we wanted to have in the product, which included high pest performance, fertilizer compatibility and an open application system,” Langdon said.

“Our Force Evo is a really good product for corn rootworms, but it requires specialized injection systems,” he said. “So, we wanted to give the grower ease of use and a direct mix into the fertilizer tank to make that application.”

The key objective of a soil-applied insecticide is to prevent as many adults from emerging out of the ground as possible.

“One corn rootworm beetle can produce from 500 to 1,000 eggs, so we really want to prevent those beetles from coming out of the ground,” Langdon said.

Opello can be applied with any starter fertilizer or water as the carrier.

“In-furrow is the key application, but on the label we allow for T-band, 2x2 and lay-by for up to 60 days after plant emergence,” Langdon said. “There’s only one application per year and with in-furrow applications at planting we’re seeing season long control of corn rootworms.”

This new product will give farmers the opportunity to choose from a wider range of corn hybrids.

“The best hybrid for a geography does not always have the best corn rootworm trait,” Langdon said. “So, the grower can select a better hybrid for their geography and use Opello.”

“There is no requirement that you need a trait, but we’ve got to think about stewardship and keeping this product viable for controlling corn rootworm,” he said. “From a resistance point of view, it’s best to put Opello on a below-ground treatment and that trait selection depends on the field.”

Syngenta submitted the label for Opello to the Environmental Protection Agency four years ago for review.

“Opello is for corn rootworms, wireworms and white grubs,” Langdon said.

“Rootworms have the potential to affect yield in several ways and it all comes down to root feeding,” said Steve Mroczkiewicz, Syngenta crop production field development scientist. “If the roots have been pruned a lot, that will stress the plants in terms of being able to draw enough water and nutrients.”

If there is a wind event or two during the summer that hits corn plants with damaged roots, that will knock the corn down.

“You’ll get goose-necking if the wind happens early enough in the year,” Mroczkiewicz said. “That won’t necessarily affect yield directly, but it will make it difficult to harvest and more of the grain may go on the ground than into the combine.”

Langdon is excited to bring Opello to market, a product that he has been working on since 2012.

“This formulation was developed by our chemists in Greensboro, North Carolina, the formulation will only be sold in the U.S. and it will be manufactured in Omaha, Nebraska,” he said. “We’re a global organization, but the concept was born in the United States and it is manufactured in the states.”

“When we started working on the development of this product, it was highlighted to us the importance of a fertilizer compatible formulation, which is one of the most challenging formulations to build,” said Elizabeth Williard, senior formulation chemist at Syngenta.

“We realized early on that not everyone means the same thing when they say fertilizer compatible,” she said.

When Williard looked at competing products, she added a field rate of the product to fertilizer and the result should be a homogeneous mix.

“But right away you can see there’s coagulation and it needs to flow through 50- and 100-mesh sieves because those are the types of screens you see on planting equipment,” the chemist said.

“A lot of the components that are known to be great solutions to formulating shelf-stable products are really incompatible with fertilizers,” Williard said.

“So we started by screening nearly 100 different chemistries, and once we locked in on one of those, we screened about 70 different variants of that chemistry to get to a field rate of Opello,” she said.

When Opello is mixed with a fertilizer, it becomes a milky, homogeneous mixture that flows right through both 50- and 100-mesh screens.

“We tested over 60 different starter fertilizers for compatibility and Opello passed every one,” Langdon said.

Sometimes during planting season farmers have to park their planters due to rain or they have an equipment malfunction.

“One of the very good things about this formulation is its suspension,” Langdon said.

“We’ve done some pretty intricate studies where we’ve tested what’s in the tank and Opello will fall out of suspension after about 24 hours,” he said. “But the agitation from the tank slosh as the planter moves through the field is enough to re-suspend Opello in the fertilizer and there are no formulation issues.”

Syngenta has focused on removing all the barriers that could make the user experience with Opello less than stellar.

“Opello brings a new technology to market, a new mode of action that the corn rootworm beetles have not seen before,” Langdon said. “It is going to give growers really good control of corn rootworms.”