The End of the Pesticide Arms Race?

To spray or not to spray, that’s the question for farmers.

Pests can be the make-or-break factor for a season’s harvest. Between 20% to 40% of global crop production is lost to pests annually, according to the Food and Agriculture Organization of the United Nations.

Conventional chemical pesticides have traditionally addressed this challenge, but their widespread use now faces growing public health concerns. 

In Missouri, the chemical giant Bayer recently settled a lawsuit involving thousands of cases that alleged exposure to its popular herbicide, Roundup, causes cancer. Numerous lawsuits are still pending in state and federal courts.

However, amidst debates over farming practices and industry-funded campaigns, another option for crop protection is taking root.

“There are a lot of groups focused on RNAi. It’s actually not new,” said RNAissance Ag CEO Steve Meyer. “It’s been around for probably a decade and a half. And it’s just, it’s been really challenging to get commercial products.”

In Kansas City and St. Louis, companies like TechAccel and its subsidiary, RNAissance Ag, are developing the use of RNA-based pesticides. This biodegradable technology is meant to be a molecularly precise solution, targeting a pest’s genes to shut down the very proteins it needs to survive.

Traditional chemicals are like a shotgun blast. The mark is hit, but the blast also creates a ton of collateral damage, hitting insects outside of its intended target. That includes insects that are generally beneficial, like ladybugs, which help control aphids and other pests, or bees, which help pollinate crops. 

RNI, on the other hand, is more of a sniper rifle; it’s programmed with the genetic information of a single target, and it leaves everything else completely alone.

“It’s a very interesting research area,” Kansas State University entomology professor Kun Yan Zhu said. “If a problem is very severe, I think many laboratories in the world are very interested in that.”

Zhu and his colleagues developed a nanoparticle-based dsRNA technology, for which the Kansas State University Research Foundation was awarded a patent in 2014. The technology is safer due to its high specificity, allowing a type of cockroach bait, for example, to only kill cockroaches without harming pets or children. 

“Many toxicologists in the U.S. are working on insights that can expand to different molecules, basically,” Zhu said. “So it’s really, really easy to kind of expand into this area, and particularly I think it has potential for pest management.”

The science

To understand RNA, you need to know some basics about DNA. 

DNA is like a cookbook for the inner workings of a living thing. The genes are the recipes on the pages, and the instructions are listed to create proteins. Messenger RNA, on the other hand, would be like a recipe card copied from the cookbook.

It’s important to note that DNA is two strands, while messenger RNA is only one. RNA interference is when another strand is inserted into a cell to create double-stranded RNA. It can be thought of as throwing in another recipe card with a different set of instructions.

Back in the “kitchen,” a large enzyme called DICER acts as a cleaver. It finds those long strands of double-stranded RNA in the cell and slices them into short interfering RNA.

Those little pieces are then picked up by the RNA-induced silencing complex, also called RISC. That’s a protein complex that will take these new little pieces and compare them to the original recipes. 

The cells have a built-in defense mechanism that knows some viruses need double-stranded RNA to thrive. Thinking that two strands of RNA could do more harm than good, if RISC finds any sequences that match, the cell signals itself to die.

It expands to more and more cells, and eventually, the process completely silences the gene. Without its recipes to create protein, the body is too imbalanced and will die from a pathogenic infection.

Related Content

Challenges

Different insect species exhibit varying sensitivities to RNAi, too. Some insects are very susceptible, while others, like some caterpillars, are more tolerant, which requires hundreds or thousands of times more dsRNA for gene silencing. 

How to address the problem with new delivery characters is a large part of Zhu’s research.

“What my focus was to understand a resistant mechanism, how to develop resistance against insecticides, and how we can improve our insecticide efficacy,” Zhu said. 

The patent for Zhu and his team’s findings was subsequently licensed to TechAccel in 2015, with the goal of commercializing the insect-control technology. 

TechAccel’s primary focus is the development of sprayable RNAi products against agricultural pests like the diamondback moth, fall armyworm, and the Colorado potato beetle — insects that tend to be more resistant to insecticides.

“Science often stays science when you leave it in the hands of scientists,” Meyer said. “How do you take science and technology and actually move it into a product?”

For 16 years, Meyer worked at Monsanto, now Bayer Crop Science, according to the RNAissance Ag website. He was first introduced to RNAi technology early in his career when some major ag companies looked at it in the early 2010s.

“They saw the potential of such a great mode of action as kind of a complementary or something that could ultimately replace small molecule chemistries in the long run,” Meyer said. “Because I had been exposed to it in that sort of organization and capacity in a bigger company, I understood really well why those projects were ultimately canceled. There were some significant technical barriers.”

Those hurdles include cost, efficacy, regulatory approval, and general public understanding.

It has been difficult to produce enough RNA material at a price that can compete with traditional chemicals. RNAissance Ag claims to have developed proprietary biotechnology methods for manufacturing dsRNA “extraordinarily cheap,” Meyer said.

Additionally, dsRNA breaks down rapidly due to UV light, rain and natural enzymes in the environment and in insects themselves. Researchers are focused on developing protective formulations and delivery systems, like nanoparticles, to make sure the dsRNA remains stable long enough to have an impact.

As a relatively new technology, regulators are still developing clear frameworks for assessment and approval, a multifaceted and sometimes slow process.

It’s not impossible, though. In 2023, another company, GreenLight, received EPA approval for a sprayable RNAi formulation specifically targeting the Colorado potato beetle.

The final step is to get the general public on board. 

“It has such a wonderful safety profile, but it does sound scary because it’s very sciencey and it’s very technical,” Meyer added. “And if you can’t explain it simply, then people are just going to be skeptical.”

This could be one of the most difficult steps, especially given the recent public fear and concerns surrounding RNA-based technologies, especially mRNA vaccines. For example, in August, Health and Human Services Secretary Robert F. Kennedy Jr. abruptly canceled nearly two dozen contracts for mRNA research.

For now, the group continues its work, and where they do it is just as important as the work itself. While most investment in agricultural technology is focused on the East and West coasts, this important work is taking place in a region that is greatly affected by its results– the Midwest. 

For years, Missouri has consistently ranked among the top states in terms of the total number of farms. It’s a fact not lost on Meyer.

“I’m a lifelong Missourian. I actually was born and raised here,” Meyer said. “I am super proud that Missouri, right in the heart of ag country, is another strong hub of plant science and agricultural technology.”

Abigail Landwehr was the summer 2025 Dow Jones Journalism Fellow for Flatland. She graduated with degrees in journalism and multimedia communication from Casper College and the University of Missouri. She hails from out west in Wyoming and brings a deep appreciation for the outdoors with her.