Helpful Bugs Can Maintain Pests Out of Farmers Fields


A South Dakota State University graduate student is studying insect-friendly field management practices that can save farmers money.

Instead of eliminating insects from arable land, Alex Michels researches agricultural practices that encourage them.

“There is only one pest for every 1700 insect species. Insects get a bad rap. And if you see a bad insect in your field and spray it, it can kill all the other 1,700 good insects too, ”says Michels.

When Michels refers to good insects, she is talking about beneficial insects that pollinate plants or break down manure or eat weed seeds or aerate the soil or eat insects that can damage crops like corn, soybeans, sunflowers, or wheat.

A recent field study by this South Dakota State University graduate student examined the efficacy of predatory insects.

“I did an experiment in some fields where I placed a caterpillar larva in the field and put it on the ground so it couldn’t move. Then I left it outside for an hour. After an hour I came back to check if the caterpillar was dead or alive, if it was being eaten, and found that I had placed 1,000 caterpillars out there and a third of them were gone within an hour. They were eaten by insects, ”says Michels.

Alex Michel’s research also addresses regenerative farming practices such as no-till and cover crops, which are known to attract beneficial insects, such as: B. Predatory insects that have eaten the caterpillars. She then assesses how much money farmers save through ecosystem services from beneficial insects. For example, if predatory insects are taking care of a pest, farmers don’t need to buy an insecticide.

Michels hopes that by demonstrating the cost savings associated with certain farming practices, more farmers will be motivated to implement practices that not only benefit beneficial insects, but also reduce the need to use pesticides.

“I think farmers have a great opportunity, they have so much land that small changes can affect so many hectares,” says Michels.

Michels’ research is funded by an Ecdysis Foundation grant. The data will be compiled and published when their work is completed in early summer 2021.

If you’re wondering why beneficial insects prefer fields that haven’t been tilled or those that have a diverse mix of plant species, Huron farmer Jeff Hemenway explains it this way.

“They need water, food and shade. And it won’t go to a field because it’s hot and dry and it’s really like a desert environment in that field. But if you get into a no-till field and it has been for a long time, the whole environment changes and all of a sudden all that debris ends up on the top of the field. Now ants are walking all the way across the field. Ants are one of those predatory insects that most people don’t think of. They are a great predator in the environment, ”says Hemenway.

Hemenway has not tilled its fields for more than 20 years. And a few years ago he experienced something similar to Alex Michels in her caterpillar research.

“A flight of cutworms came in and not too detailed to explain, but you can actually see their eggs, they are bright orange and they were laid on top of the debris in the field. And because I have been in a varied rotation and no-till sowing for a long time, I have many useful insects in the field. I just wanted to see if they would be a pest in the field. So I went and marked the area so I could see where it was. And I kept exploring and looking at the plants in this area. And you know, the bottom line is I can tell you what happened. Nothing. Nothing happened because the insect populations are beneficial and actually killed the pest. I ate these eggs before they became a pest in the field, ”says Hemenway.

And whenever his management practices cause nature to take care of a problem for him, Hemenway says it’s a win-win situation.

“As a farmer, I think one of the first things you want to do, of course, is make money like everyone else. But at the same time, you know, there is an administration. In other words, it’s your responsibility to take care of the environment, which are the fields you have, ”says Hemenway.

Another reason why Hemenway is slow to use pesticides is being a beekeeper in addition to harvesting. He turned bees after hearing a speaker talk about how the pollinator insect might help increase soybean yields.

“If you have a beehive near a soybean field, you can see up to 4 bushels more per acre,” says Hemenway.

At the current market price of around $ 13.70 per bushel, an additional 4 bushels per acre can mean a lot when harvested.