From Lethal Viruses to Insect Sex, Farmers Use Bugs to Kill Bugs

For decades, Adam Baldwin’s family used chemicals with multisyllabic names to keep caterpillars such as earworms and podworms from chomping their corn, soybeans, and sorghum. While the pesticides were generally effective in getting rid of the hungry invaders, they also killed beneficial insects such as ladybugs, which help control aphids that cover crops in a gooey residue and reduce yields. So for the past two years, Baldwin, a fifth-generation farmer in McPherson County, Kan., has used a lab-grown virus that takes out the caterpillars while leaving other bugs alone. “It’s very specific to the one insect, a safe product,” he says. “It killed what we were going after, but it didn’t kill what we weren’t.”

Baldwin uses Heligen, a natural virus harvested from infected caterpillars that’s sprayed on crops at the first sign of infestation. The virus spreads among the bugs, and each infected insect becomes a source of infection for others, giving further protection to the crop as it passes from generation to generation. “Once the caterpillars feed on the virus, they die and liquefy and release billions of new virus particles,” says Peter Berweger, chief executive officer of AgBiTech Pty Ltd., the company that makes Heligen.