Rather than turning to toxic chemicals to rid farm fields of destructive insects and noxious weeds, some farmers in Missouri are recruiting chickens and bugs to do the job for them.
The 40 acres of land purchased by Gary Wenig and his wife to grow organic crops were initially overrun by weeds and insects. In order to grow truly organic plants, the couple had to eschew products like Roundup and atrazine. Synthetic pesticides are permitted for organic growing, but they’re expensive and can still be toxic.
Instead, Wenig decided to experiment with “trap crops” – sacrificial plants not raised for harvest, but that provide a yummy meal for squash bugs and other pests. The destructive insects were attracted to the trap crops, like Blue Hubbard squash, while leaving Wenig’s zucchini largely untouched.
“The bugs will move in and they’ll stop at that point and eat those plants. So then you spray that portion of your garden only. You don’t have to spray the food you’re eating.”
In an effort to cut out all pesticides, Wenig took the extra step of purchasing free-range chickens, who love feeding on bugs.
After Wenig planted the trap crops, he rolled out a chicken tractor – basically a big, mobile chicken coop on wheels with a mesh-wire bottom – and let several of the chickens chow down on the bugs from above.
This method may work for smaller farms like Wenig’s, but it might not be effective on larger, conventional ones. So academics and the U.S. Department of Agriculture (USDA) are investigating ways to battle pests by introducing predatory bugs.
Anyone can purchase ladybugs at garden stores for the purpose of releasing them in their gardens to feast on aphids that demolish tomato plants. But insects like the soybean aphid can damage acres’ worth of land, and are harder to combat because they show up in large numbers.
Ben Puttler, professor emeritus of entomology at the University of Missouri, Columbia, explained:
“Take the soybean aphid right now. It’s considered a pest because [farmers] don’t have its natural enemies. And we’re trying to introduce natural enemies for it.”
Soybean aphids, which suck the juices out of soybean plants, emerged in the United States around 2000. The pests leave the plants full of fungus and mold, and can trash up to 40% of a farmer’s crop.
The fight against the destructive aphids sent researchers on a journey to China and Japan to find a minuscule parasitic wasp, the soybean aphids’ natural enemy. The wasps work by injecting their eggs into aphids. From there, the larvae eat the aphid from the inside out before emerging as an adult wasp.
“You can look at it this way. We have an army. And the wasps are the air force, and the ground force are the predators.”
Natural predators are being tested by researchers for other pests as well, including stink bugs and the emerald ash borer, which have been known to decimate ash trees all over the U.S.
Certain plants can also be a major hurdle for farmers, including the invasive garlic mustard. The plant arrived here from Europe and has been spreading across the Midwest for a number of years. According to Hank Stelzer, garlic mustard is easy to yank out of the ground, but “The problem is there is just so many of them.”
Mustard garlic prevents grass and tree seedlings from starting, making it more difficult for grazing pastures and timber forests to reproduce. A handful of weevil and tiny wasp species are currently being tested by researchers to fight the weed. Said Stelzer:
“Some will attack the leaves, some will attack the stems. They will both suck the life, if you will, out of the plant. But that’s also where they lay their eggs, so they get more of those critters out there.”
However, introducing a new species to an ecosystem is risky business. Stelzer explained that the USDA first conducts rigorous tests in quarantined labs for that very reason. These tests are conducted in controlled environments – in greenhouses and growth chambers – before any real-world testing occurs.
It can take decades for methods to gain regulatory approval; many simply don’t pan out.
Wenig has plans to expand his crop perimeter to encompass the entirety of his garden plots. He has partnered with Lincoln University to do more studies and is hopeful he’ll get another USDA grant to help fund the project.
And when the next growing season rolls around, Wenig will plant more plants to attract ladybugs and dragonflies, which eat pest bugs. He said:
“We’re going to build two fences with about 15 feet in between them so we can get the tractor in there. And we’re just going to plant nothing in there but sacrificial plants and beneficial insect plants.”