PEORIA — One syllable mostly sums up the universe of consumer insect repellants. Though there are alternatives, deet has proven its efficacy in hundreds of millions of applications over decades.
But a pair of research projects at the National Center for Agricultural Utilization Research — more commonly known as Peoria's ag lab — have produced results that match or exceed that most common chemical's effectiveness using more all natural ingredients.
One project has developed a novel adaptation of an oil already commercially available in abundance, while the other has found a new source crop and method of extraction for a compound already known for its repellant properties.
"Once we find something unique and interesting, we think about what we can use it for," said research chemist James Kenar. "The challenge for us as chemists is once we do find something unique and different, how do we apply it?"
For Kenar and Steven Cermak, lead scientist in bio-oils research, those types of questions led them to investigate the use of fatty acids as insect repellants. With partners at the University of Nebraska, they looked more specifically for a way the livestock industry could deal with biting flies.
They found their solution in coconut oil. Using basic processes such as hydrolysis, which already is widely used in commercial production of certain compounds, the scientists derived a stable solution containing a free fatty acid that could be applied to cattle using a field sprayer.
"That's what's neat about this — it's strait chemistry that's already being used in commercial operations," Kenar said. "It just kind of dries on their hair, it sticks to their hair, and since it's not volatile, it sticks around."
Early testing showed the coconut-oil-derived solution retained its repellant property for nearly 100 hours per application, indicating its potential for other long-term products such as pet shampoo.
For a different compound that is known to be particularly repellant for ticks — 2-undecanone — Cermak and research chemist Michael Jackson turned to a different source crop all together.
The chemical already is available in a limited number of insect repellant products that claim to derive it from wild tomatoes, but the Peoria scientists found cuphea to be a more reliable source.
The plant grows purple flowers and yields about 600 pounds of seeds per acre, or about 200 pounds of oil, of which approximately 70 percent can be converted to the fatty acid necessary to derive 2-undecanone.
"It's a low yield, that's one of the problems," Cermak said. "And it's a challenge to harvest when most of the seeds are ripe but have not yet been dispersed."
The plant, however, shows potential as a rotation crop in lower yield areas of the upper Midwest, where it could be planted between corn crops to help break up corn root worm in the soil.
The resulting cuphea oil could easily be converted into a naturally sourced insect repellant on a commercial scale.
"I'm optimistic it would scale up quite well," Jackson said. "And it's comparable to deet, but deet does not repel ticks at all, so it works better than deet on ticks."
Matt Buedel can be reached at 686-3154 or firstname.lastname@example.org. Follow him on Twitter @JournoBuedel.