Iowa Farmers Taking Aim at Soy-Eating Butterflies

SIOUX CITY, Iowa (AP) – Some western Iowa fields are getting sprayed to get rid of painted lady butterflies that have proven problematic for soybean crops.

Iowa State University Extension field agronomist Joel DeJong says the agricultural community believes this year’s influx of the painted lady butterfly, or thistle caterpillar, is the largest ever in Siouxland.

DeJong said Friday that painted lady butterflies have been known to chew half of the leaf area on soybeans. That led farmers to hire flying crews to begin spraying an insecticide. The Sioux City Journal reports that spraying began in July and is ongoing.

The painted lady butterfly normally passes through the region but is spending more time there than usual. DeJong says the region’s current climate has enabled the thistle caterpillars to thrive.