2020 is a year for rolling with the punches – in this case, miller moths in Wyoming.
Miller moths are a common name for the adult stage of an army cutworm, Euxoa auxiliaris. A recent press release by the University of Wyoming states that the moths are following flowering plants as they begin blooming across Colorado and surrounding states.
Colorado has a miller moth season — although for the last several years population numbers have been dramatically lower than expected this season. According to a 2020 Colorado State University article by Anne Manning, the moths cut across Nebraska and Kansas through Colorado to the mountains for the summer months before leaving in September.
University of Wyoming Extension entomologist Scott Schell said that environmental conditions have been working in the moths' favor. They’ve been moving into urban areas partially due to dry conditions outside of town, with fewer flowers to feed on. Towns offer lush greenscapes as people water their lawns, and a higher flower population to sustain them.
“The eastern plains had more reports of crop damage to alfalfa and winter wheat caused by the miller moth larvae, called cutworms, than usual,” Schell said in the release. “That was followed up by dry conditions on the sagebrush steppe and prairie producing few wildflowers for the moths to gather nectar at.”
The moths are luckily not a long-term issue: They’re on their way to higher country on their annual summer migration. Schell said they likely hang around until a warm southern front comes through.
Teton County itself has no recorded sightings as of yet, according to the Teton Weed and Pest District.
If they do arrive in Teton County, Schell suggests turning off outdoor lighting and checking screen doors to minimize the annoyance of having them around.
“Checking your window screens and weather seals for cracks big enough to let them in and fixing them helps exclude them when they seek out places to hide for the day,” Schell said in the release.