Guide to Surviving Moth Season
Yup, moths. Rather than spring, summer, fall, and winter, Colorado’s seasons include Almost Spring, Just Kidding, and Optimal Skiing, followed by Moth, Afternoon Hail, On Fire, Still Too Hot, Fall For One Week, Dark, Cold, and Ice. We’ve already moved past Moth Season this year, but it’s never too early to plan for the next!
Moth Season (noun, def.): Early spring in Colorado when miller moths make their way from the Midwest and eastern plains to Colorado’s foothills in apocalyptic numbers, finding their way into homes and cars as residents fight a losing battle with both insect and sanity.
Recognizing Miller Moths
Photo Credit: The Gazette
If you live in Colorado and your home is under siege by a party of large, dark moths in the spring, they are miller moths (Euxoa auxiliaris). While we might be forgiving of a more visually attractive moth, the miller moths have no such luck. They are a dull brown-grey, flecked with white, and very large, which also makes them undesirable houseguests.
Where Do They Come From?
You might know miller moths by their alias, “army cutworms” - the caterpillar stage of these moths. The infographic below outlines the life cycle of miller moths, from their destructive teenage phases to their inevitable adult incursion into the foothills.
If you are using a assistive technology, please click here for a detailed description of the infographic.
Image Credit: Made by Hailey Robe using Canva. Based on information from W.S. Cranshaw, CSU Extension.
Terrible Teens: Miller moth caterpillars, a.k.a. army cutworms, are known for their tendency to feed on plants in huge quantities, damaging crops such as alfalfa and wheat. In particularly high numbers, they have been observed to group together and crawl across fields and roads, giving them the “army” nickname.
Why Migrate? Miller moths begin their lives in the plains and fields of the Midwest and Eastern Colorado before migrating farther west to the foothills because, like the rest of us, they are looking for food and enjoyable weather. Miller moths prefer mild summers, so if we have a stretch of hot days at the very beginning of summer, they won’t stay very long. However, if we have a mild beginning to the season with lots of wildflower growth, they might extend their stay for a couple weeks.
Please, How Can I Keep Them Out of My Home?
Photo Credit: Texas A&M AgriLife Extension
If you have experienced Moth Season before, you have inevitably screamed this question into the (moth-filled) night.
You’re not alone. Seth Boster writes a compelling and relatable article, “War and peace with the miller moths of Colorado,” which captivatingly begins:
“They come at night, as invaders do. Flying in a very ungraceful way, a menacing way, like miniature kamikazes. Their bodies are like furry bullets, their gray and vomit- green wings like something from hell. My hunt begins.”
And yes, one way to handle them is simply by killing them, whether your weapon of choice is a newspaper, a bucket of soapy water to draw them in and drown them, or a shoe that may do more harm than good - my sister once nearly broke our TV in a frantic battle with a miller moth.
However, kinder alternatives include trapping them with a cup and releasing them outside, or keeping your lights off at night and sealing potential entry points to your residence. If possible, these are preferable to killing them - as entomologist Lisa Mason (CSU Extension) says, “They do have a role in the ecosystem so they can pollinate flowers that they forge on at night... And then they also are food for a lot of other organisms, birds, bats, and other wildlife in our ecosystems.”
That’s right - they’re pollinators. So, if we can find it within ourselves to spare these dreadful intruders, our environment will be healthier for it. And ultimately, the moths are harmless. As we’ve learned, they won’t lay eggs in your house - they need alfalfa, wheat, or thick grass fields. They won’t bite or attack your dog. They only bang their wings against the glass because they’re stressed and confused, which I’m sure we can agree is relatable. Plus, they’ll be out of your hair in a couple weeks!
In all seriousness, miller moths deserve our respect, just like any other insect. Hopefully, this post shed some light on these insects (which is exactly what you shouldn’t do if you’re trying to keep them away) so that you’re prepared for next year’s Moth Season. In the meantime, happy Afternoon Hail.
