Malacomosa Dance

Malacomosa Dance: Caterpillar Distraction Courtesy & Copyright Shannon Rhodes, Photographer
Caterpillar Distraction
Courtesy & Copyright Shannon Rhodes, Photographer
My father’s first caterpillar encounter has always been a bedtime favorite. The story goes that a plump fuzzy one was crawling on his picnic blanket one afternoon. I would imagine him watching its five pairs of prolegs innocently undulating along. Then, Dad ate it, hairy bristles and all. My first encounter was almost as tasty but longer-lasting because it came from the pages of Eric Carle’s picture book classic, The Very Hungry Caterpillar. A recent New York Times article reporting the author’s passing reveals that Carle’s interest in crickets, fireflies, and other insects was sparked as a child by peeking under bark or stones walking in the wild with his father.

Western Tent Caterpillars Malacosoma californicum, Courtesy & Copyright Shannon Rhodes, Photographer
Western Tent Caterpillars
Malacosoma californicum
Courtesy & Copyright Shannon Rhodes, Photographer
There’s nothing like a caterpillar, green or woolly, slinking along in the dirt or hanging by a thread from overhead branches, to distract a group of young outdoor learners. I resist the urge to caution them that there are poisonous caterpillars in the world, and we play. Yet, how many times have I encountered a silky mass in the limbs of a chokecherry, stopped and watched the caterpillars wiggle and twitch, and wished that I knew more about them? The magic for me of being out in the forest meadows this time of year is coming home with more questions than answers. So, becoming a novice lepidopterist, I focused this week on learning about caterpillars, butterflies, and moths. The frenzied dance of this caterpillar, what I think is known by the lyrical name Malacomosa, is not to draw me in for a closer look; the tent caterpillar senses a predator is near and gets the whole gang going. Soon these gorging wigglers will be settling into silky cocoons and emerging as moths. According to Eric Carle’s website, he intentionally had his butterfly come from a cocoon rather than a scientifically-accurate chyrsalis because it sounds more poetic, and my budding readers appreciate being able to more easily stretch and blend cocoon sounds anyway. We do use the word caterpillar, though, for both moth and butterfly larvae, but that is where many of the similarities end.

Drab Moth, Courtesy & Copyright Shannon Rhodes, Photographer
(Not so) Drab Moth
Courtesy & Copyright Shannon Rhodes, Photographer
Butterflies get noticed because they flutter during the day, while moths are typically more active by night. In fact, when I am outside I turn to my Kaufman Field Guide to Butterflies because I never thought to purchase a book on identifying moths. The first thing it says to do is look at the antenna. A butterfly antenna has a club tip, and often a moth has thick and feathery antennae to help it pick up scents flying around at night. Butterflies have names like swallowtail, fritillary, metalmark, and checkerspot, and moths just rhyme with sloths. Compared to butterflies, moths are generally smaller and drab in color. Drab? I met a moth resting on a twig once that was anything but drab. Its chunky abdomen was striped black and the most vibrant tangerine orange imaginable, and I was mesmerized. Moths should get more love, especially when you know that there are so many more kinds of moths than butterflies to enjoy. Consider getting out to notice the wonder of moths with other citizen scientists for National Moth Week 2021 this July 17-25.

Writing from the Central Utah Writing Project, I am Shannon Rhodes and I’m wild about Utah.

Images: Courtesy & Copyright Shannon Rhodes, Photographer
Additional Audio: Courtesy & ©
Text:     Shannon Rhodes, Edith Bowen Laboratory School, Utah State University
Additional Reading Links: Shannon Rhodes

Additional Reading:

Brock, Jim. Kaufman Field Guide to Butterflies of North America.

Carmel, Julia. Eric Carle, Author of ‘The Very Hungry Caterpillar,’ Dies at 91., The New York Times, May 26, 2021.

Eric Carle Official Website.

Florida Museum of Natural History. Butterflies and Moths.

Forest Health Protection. Western Tent Caterpillars. 2011.

National Moth Week.

Wild About Utah Posts by Shannon Rhodes

It’s Miller Time – Miller Moths

Miller Moth Adult, Courtesy, Whitney Cranshaw, Photographer
Miller Moth/Army Cutworm Adult
Euxoa auxiliaris
Whitney Cranshaw, Colorado State University, Photographer

Miller Moth Adult, Courtesy, Whitney Cranshaw, PhotographerMiller Moth/Army Cutworm Adult
Euxoa auxiliaris
Whitney Cranshaw, Colorado State University, Photographer

Miller Moth Adult, Courtesy, Frank Peairs, PhotographerMiller Moth/Army Cutworm Larva(e)
Euxoa auxiliaris
Frank Peairs, Colorado State University, Photographer

Hi, I’m Holly Strand from the Quinney College of Natural Resources at Utah State University.

World Cup Colombian soccer player James Rodriguez isn’t the only one with a flying insect problem. For several weeks many Utahns have been coping with a bumper crop of miller moths. These dusty gray nuisances have been mobbing our lights, dive bombing our heads and plopping into our nightstand water glasses. Miller moth annoyance levels seemed highest along the Wasatch Front but other areas experienced high numbers as well.

Miller moths begin their lives as army cutworms. The larvae eat their way through the winter chomping on winter wheat, alfalfa, and many other types of crops and plants. After eating all winter, the army cutworms burrow into the ground to pupate. They emerge six weeks later with a yen for flower nectar. This sets them migrating to the alpine elevations of the Wasatch and Uinta Mountains. However, flowery trees and gardens along the Wasatch front are powerful diversions; thus our yards function as filling stations along the miller moth migration route.

Army cutworm populations soar during relatively warm winters with little snow cover. And that’s what happened this year in the south central counties of Utah. And that’s why we have so many moths now. But to keep this issue in perspective—know that the numbers we see in UT are nothing compared to the annual invasions experienced by populations on the Rocky Mountain front range. In Denver, annual spikes in vehicle crashes, therapist visits and broken light fixtures clearly coincide with the influx of miller moths.

Luckily, the moths are no more than a nuisance – they won’t eat your food or damage clothing or upholstery. And while sometimes it seems as if they are targeting your head, they really aren’t. If they are in your house, it’s because they were seeking shelter from the daytime predators by seeking a dark crack or crevice to crawl into—and then got into your house by mistake.

If you swat these unfortunate moths, they’ll get back at you. They leave a dusty gray, powdery mess. The powdery dust is really the moth’s tiny scales and is what gave the moth its name. For these scales are reminiscent of the dusty flour that covers the clothing of someone who mills grain.

For a clean resolution to the problem, veteran miller moth killers from Colorado suggest you suspend a light bulb over a bucket of soapy water. Moths will flick off the bulb into the water. At our house we catch them with a butterfly net and set them free outside. For I imagine that they will be off to the mountains as quickly as possible after that experience.

In early fall, the moths return to lower elevations to lay their eggs. Enough have died during the summer so we won’t notice them much if at all. But if next winter is also mild, we will be hosting our miller moth friends again.

Thanks to USU biologist Diane Alston for sharing her entomological expertise.

For pictures, sources and tips for living with miller moths, go to

For Wild About Utah, I’m Holly Strand.


Images: Courtesy & Colorado State University Extension, Whitney Cranshaw and Frank Peairs, Photographers
Text: Holly Strand

Sources & Additional Reading

Cranshaw, Whitney. Quick Facts about Miller Moths. Colorado State University Extension, Fort Collins, CO

Cranshaw, Whitney and Frank Peairs, Questions and Answers about Miller Moths Colorado State University Extension

Sphinx Moths

Sphinx Moths; Big Poplar Sphinx, Pachysphinx occidentalis, Courtesy Whitney Cranshaw, Colorado State University,
Big Poplar Sphinx
Pachysphinx occidentalis
Courtesy Whitney Cranshaw
Colorado State University

White-lined Sphinx
Hyles lineata
Courtesy Whitney Cranshaw
Colorado State University

White-lined Sphinx Caterpillar
Hyles lineata
Courtesy Whitney Cranshaw
Colorado State University

I vividly remember the first time I saw one – a small winged creature whirring from flower to flower in the evening light, its long tongue dipping for nectar within tube-shaped blooms. I was mesmerized, and struggled for a closer look.Sphinx Moths

If you’re thinking that I must have seen a hummingbird, you would be making a very common mistake. A mistake, in fact, that has given this critter one of its many nicknames. The winged wonder I saw that summer night was a sphinx moth, also called a hummingbird or hawk moth because of their large size and bird-like characteristics.

In all stages of their life, these insects are large. Caterpillars grow to a robust 4 inches in length and adult wingspans can measure more than 5 inches. Sphinx moths are also some of the fastest insects on earth and have been clocked flying at over 30 miles per hour. Their size, speed, and flying ability reflect those of the hummingbird so closely that they are commonly misidentified.

Sphinx moths are a beloved sight in many Utah gardens. However, they also hold a bit of a devious surprise. The larvae, or caterpillar, of one common species of sphinx moth are well known by vegetable gardeners. They are large and bright green with a distinctive horn near their hind end. Like the adults, these larvae go by many names, the most common being the tomato hornworm. Hornworm caterpillars, unlike their adult counterparts, are not beloved by gardeners. They are voracious beasts with the ability to strip the vegetation off a tomato or pepper plant in one day.

Aside from our garden plants, young hornworms of other species feed on a variety of vegetation including willow, poplar and cottonwood trees. Adult moths rely on a host of flowers such as columbine, honeysuckle, larkspur and evening primrose. Here in Utah you might come across one of a handful of different species in the sphinx moth family including the five-spotted hawk moth and the white-lined sphinx. Look for them in the late summer evenings as daylight begins to fade. But be sure to look twice to avoid mistaking them for something they’re not.

And the next time you find a hornworm on your tomatoes, maybe just relocate the little bugger so that you can enjoy it once metamorphosis changes the beast into a beauty.

For more information and pictures of our native sphinx moths, visit our website at Thank you to Rocky Mountain Power Foundation for supporting the research and development of this Wild About Utah topic.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Photos: Courtesy Whitney Cranshaw, Colorado State University,
            Images licensed under Creative Commons Attribution 3.0 License
Text:    Andrea Liberatore, Stokes Nature Center,

Additional Reading:

Cranshaw, W.S. 2007. Hornworms and “Hummingbird” Moths. Colorado State University Fact Sheet 5.517. Found online at:

Buchman, Steve. 2010. Pollinator of the Month: Hawk Moths or Sphinx Moths (Sphingidae). US Forest Service. Found online at: