Utter the word, “moths,” and many folks quickly conjure up a picture of some annoying, brown, flying creature who leaves holes in your sweater, lays eggs in your cereal box, or if you’re a farmer, is simply a pest! Poor moths…they need some good “PR!” So I’m going to give it my best shot. Most creatures are more complex and interesting than our first impressions.

Now I imagine you’re thinking: “It’s winter and she decides to write about moths??? They’re not even around in the winter!”

Actually, moths – the outdoor ones I want to talk about – are hardly ever seen at any time of year. Many, but not all of them, are nighttime creatures, after all. But actually, they are all around us right now in any natural area where unmown leaves cover the ground. Their caterpillars spin cocoons that cling to bark or are wrapped around twigs high in the canopy of bare trees. Some cocoons stay there all winter. Others fall to the ground to be warmed by the leaf litter on cold winter days. Still other moths spin their cocoon near the base of trees to be insulated later by falling leaves. So if you’re in a woodland, or even if you just have trees around your home, moths surround us throughout the year.

[A note: Ewa Mutzenmore, a Wednesday bird group member and skilled photographer provided photos of two Giant Silk Moths for this blog. She raised Promethea and Luna moths from eggs and documented the stages with photos which she generously shared. She posts more of her work at Mutzenmore Photography on Facebook. Gail Morrell, another bird group member and a professional gardener, shared her beautiful photos of two other Giant Silk Moths moths she raised from cocoons- the Polyphemous and the Cecropia. So, I am one lucky blogger! Thank you both for giving me permission to share the photos below!]

So, What Should We Appreciate about Moths?

The Sheer Number and Diversity of Species are Huge Compared to Butterflies!

Let’s begin with the fact that worldwide, the genus Lepidoptera contains around 180,000 species – and 160,000 of them are moths! Only about 20,000 are butterflies. According to the University of Michigan BioKids website, Michigan hosts about 2000 species of moths but closer to 146 species of butterflies – and many small moth species have yet to be identified!

Moths are a Critical Park of Any Local Food Web

Moths are prolific. Each mated female can lay from a few hundred to thousands of eggs in a summer, depending on the species. They’re often tucked on the underside of leaves like these on a Black Oak leaf (Quercus velutina) in my back yard.

Actually though, only about one percent of all moth eggs survive to become adult moths. As any reader of this blog knows, the eggs themselves are often food for birds, ants and beetles among other creatures, while the caterpillars and their pupae are a favorite food of most songbirds, summer and winter. The soft caterpillars, filled with fat and protein, are ideal “baby food” for their nestlings, too. For example, caterpillars make up 80-90% of the diet of a Red-eyed Vireo (Vireo olivaceus). Jim McCormack, a field biologist for 30 years for the US Fish and Wildlife Service, estimates that the one million Red-eyed Vireos that migrate each year to his state, Ohio, consume about thirty million caterpillars each day during their stay! (Much of my information in this blog comes from Jim’s highly informative and entertaining online presentation, Mysterious Moths with Jim McCormack). Author and entomologist Doug Tallamy gives the example of a pair of Black–Capped Chickadees (Poecile atricapillus) who require 6-9,000 caterpillars in a season to raise just one clutch of nestlings. And that’s only two species!

Other moth caterpillar predators include spiders, who snag and eat them, and parasitic tachinid flies and ichneumon wasps, which have the nasty habit of laying their eggs on caterpillars, thereby providing their hatched young with a ready food supply! I reported in an earlier blog about seeing such a wasp threatening a Dagger Moth caterpillar which thrashed wildly to drive it away. Every habitat in the world depends on insects and their caterpillars as the foundation of its food web. And moths are champions at reproduction.

In fact, most moths may have evolved to be nocturnal in order to avoid hungry birds. But their fluttering does attract bats who find them through echolocation and eat them in large numbers. Moths sometimes drop to the ground in an attempt to escape them. Luna moths trail long tail streamers that can also confuse the bats “radar” and can break off when bats seize them, saving the rest of the moth. Scientists at Wake Forest University are studying one species of western Tiger Moth, Bertholdia trigona, to verify that the loud clicking sound that it makes with organs on it wings jams the echolocation signal of bats. Some moths can whistle through openings on their side called spiracles, a sound which may also confuse bats. Nature invents survival strategies for both predator and prey!

Most Moths Take the Night Shift – and Some Take the Day Shift – in Pollination

Butterflies have lovely, delicate wings and are smoother and more slender than moths. Moths have a more sturdy appearance with their burly, fuzzy bodies. Those “furry” bodies can be beautiful too, and they also pollinate more efficiently. Pollen gets caught and transported in the “fur” as they feed and move between blossoms. The thinner, smoother bodies of butterflies can’t transfer as much pollen. According to Frontiers, a research publishing website, moth hair may also absorb the pinging sound of bat echolocation, making it harder for bats to locate their prey. So being fuzzy has its advantages!

Day and night, some moths are out pollinating native flowers as they search for nectar or mate. At night, they are especially drawn to the scented , light-colored blooms that reflect moonlight, like Evening Primrose. Other flowers associated with moths include Buttonbush, Culver’s Root, Arrowhead, Swamp Rose Mallow, American Plum, Native Honeysuckle, Wild Bergamot/Bee Balm – and oddly enough, thistles of all kinds! (Turns out thistles produce lots of nectar!)

Moths Are Masters of Disguise

The Rosy Maple Moth (Dryocampa rubicunda) can use the Red Maple (Acer rubrum) as a host plant for her young because she’s well camouflaged when laying eggs; her wing shape and color scheme is very similar to the whirling fruits (samaras) of that tree. So many interesting adaptations among moths and their native plants!

Interestingly, some moths don’t really look like moths at all! Their protection is in looking like some other unappetizing creature – like a bee or wasp, for instance! Have a look at the Rose Plume Moth (Cnaemidophorus rhododactyla) that Ewa Mutzenmore found on her non-native Rosa rugosa shrub.

The first time I saw a diurnal Snowberry Clearwing Moth (Hemaris diffinis), I thought I was looking at a very large bumblebee. But on closer inspection, the gold and black creature was clearly something very different – a moth. Clearwings hover over blossoms like a hummingbird, extend their very long proboscises and reach deep into tube-shaped blossoms. They evolved to reach the nectaries that are often far down next to the stem. The gold with black bands of the Snowberry Clearwing may protect it from predators who are afraid of a Bumblebee sting. No stingers on moths, though!

Later, Ben VanderWeide, our township Natural Areas Stewardship Manager, pointed out a diurnal Hummingbird Clearwing Moth (Hemaris thysbe) sipping from a long, tubed phlox blossom . At first glance, this moth hovering over a blossom with its lovely, mostly transparent wings edged and filigreed in crimson could easily be mistaken for the Hummingbird itself, instead of a Hummingbird moth!

Big, Beautiful, Nocturnal: Four Local Giant Silk Moths

Since most moths are nocturnal, we seldom see them. But here in southeast Michigan, we are lucky to occasionally catch sight of one of our four Giant Silk Moths: the Promethea, the Polyphemus, the Luna, and the largest native moth in North America, the Cecropia. These silk moths (family Saturniidae) are so called because they spin silk that is as fine as a hair from a salivary gland . They use the silk to create their cocoons and/or attach their cocoon to a branch or leaf. [Please note, these silk moths are not used in producing scarves or silk underwear! These days, silk is mass produced from a flightless moth specifically bred for silk production.]

All moths have a complete metamorphosis: from egg, to larva (caterpillar), to adult. The caterpillars develop in stages called “instars,” and molt from instar to instar. Each time it molts, the caterpillar attaches itself to a bark, a twig or a leaf by secreting a sticky substance, cracks open its exoskeleton and walks out of it. Usually, the caterpillar eats the old exoskeleton, either to gain back some nutrients and/or to leave less evidence for predators.

The caterpillar of the last instar eats ravenously to provide the adult moth with enough energy to feed and mate. (They rarely eat enough to harm a tree.) Most adult nocturnal moths can also feed on nectar, pollinating as they go, like butterflies. But not the Giant Silk Moths! These beautiful, big moths never eat at all; they live on the fat stored by their caterpillars. In fact, while undergoing transformation inside their cocoons, they develop reproductive systems, but lose functional mouths and their digestive systems. They can’t eat! Mating is their only assignment in their brief lives of a week or so at most. So come meet these four amazing creatures,

Promethea Silk Moth (Callosamia promethea)

Ewa Mutzenmore received her Promethea eggs from a knowledgeable member of a caterpillar group to which she belongs. She managed to raise the caterpillars through all five instars. Have a look at this short slide show to see how they change with each molt.

The fifth instar produces silk to attach itself and its cocoon to a thin branch.

It spins a cocoon around itself. When the leaf turns brown, the cocoon looks like any other leaf dangling from the tree. Birds can find it difficult to get into the silky cocoons and mice, another predator, can’t venture out on thin branches. Inside this nifty cocoon, the caterpillar liquefies and metamorphoses into the adult butterfly – one of nature’s most amazing transformations.

When the adults emerge (eclose) in spring, they pump hemoglyph (moth blood) into their wings to extend them and then wait until they harden and dry. With those large wings (3.5 to 6 inch wingspan), giant moth adults have only one goal. Find a mate! The process is a little trickier for Promethea moths because the male is diurnal and the female is nocturnal. They only have a few hours in the early evening when their lives overlap. The female stays put, camouflages herself and sends out a mating scent, a pheromone, to any interested male. She won’t fly until she’s mated. The male then follows her pheromone trail, sometimes for miles, to find her. Aren’t they a handsome pair!

Cecropia Silk Moth (Hyalophora cecropia)

The Cecropia often gets top billing because it’s the largest native moth in North America! Its wingspan ranges from five to seven inches! The male may fly up to seven miles to mate and the female then lays up to one hundred eggs. If you live or hike near maples, you’re most likely to see them because it’s their favored host plant, but they also frequent cherry and birch trees among many others.

Gail Morrell found a Cecropia cocoon while working as a professional gardener and raised it at home. She says she was so busy providing leaves and tending a voracious passel of early instars, she didn’t get photos of the early instars. But she got fine ones of the last three. I’ve added a couple of extra photos I found at Wikimedia Commons to further illustrate the cartoon-like color scheme of that 4th instar (amazing!) and a cocoon in its natural setting. Watch it change in the slideshow.

I came across this lovely short video of a Cecropia Moth just after it eclosed, i.e. emerged from its cocoon. It’s pumping up its wings with hemolymph from its abdomen, waiting for the wings to dry and harden. If you have time, this short video edits a two hour process for the moth down to just two minutes for us. Quite fun to watch!

And here are adult Cecropias in all their final glory. Look at that striped abdomen! Male and female Cecropias are mostly differentiated by the male being smaller but having larger, “feathery” antennae. The color of both genders can vary somewhat. In these photos, the male is redder and female is gray.

Luna Moth (Actias luna)

Who can’t love the elegant kite shape, fluttering wing “tails” and soft green of a Luna Moth? But beyond being big (4.5 to 6 inches) and beautiful, it’s a tough survivor as well. Its caterpillars can emit clicks and even vomit to drive off predators. The long tails can be twirled in flight to throw off the echolocation of predatory bats. They can also save the moth’s life if a bat nips the tails but leaves the moth flying off into the darkness. Its eggs and later caterpillars can be found on its preferred host plants – walnuts, hickories, paper birch and sumac among others.

Ewa, like Gail, found herself too busy for photos because of harvesting the volume of walnut leaves needed to feed big, hungry caterpillars. But she did get a great photo of a first instar emerging from its egg and also what I think is a third instar eating; I found photos of the fourth and fifth instars at Wikimedia Commons. I also found a helpful video which shows the development of a Luna edited to one minute. Pretty helpful for an inquisitive blogger trying to sort out one instar from another! The fifth/last instar descends to the ground, wraps itself in a leaf and spins silk around itself to create its cocoon. More falling leaves will add insulation.

Ewa was able to get a photo of her female Luna in the spring with its normal green color. The male she found in August was more yellow, the color that they have more commonly in the South. Such elegant creatures!

Polyphemus Silk Moth (Antherea polyphemus)

The Polyphemous Moth with its single large eyespot on each hindwing got its name from the one-eyed giant of the same name in Homer’s Odyssey. It’s a widespread species in the continental US and its caterpillar can eat a wide range of host plants and rarely harm the host. Their preferred hosts are elm, birch and willow but the caterpillars can eat many others as well.

Like other Giant Silk Moths, the caterpillars that emerge from the eggs develop through five molts. The fifth instar weaves a cocoon with brown silk, usually within a host leaf. Some cocoons hang in the trees all winter, some fall into the leaf litter, and some Polyphemus moths choose to spin theirs on the ground.

According to the website of the Entomology Department at the University of Florida, both the Luna and Polyphemus have no escape “valve” from their cocoon, like the Promethea and Cecropia do. Instead they release an enzyme (cocoonase) to soften the cocoon and then twist within the cocoon ripping it open with hard spurs at the base of their thorax – and out they come! Lots of great closeups of the stages of these moths at the link above!

In our area, the female Polyphemus mates once each year. As usual, she stays in place camouflaged and starts the mating process by sending out her pheromone for the male to follow. Once mated, they stay coupled for a whole day and separate at dusk. The female waits one day after mating and then spends the rest of her brief life (usually less than a week) laying her fertile eggs; the male may mate several more times before expiring.

Here’s a brief slideshow of Gail Morrell’s photos of a female Polyphemus moth she raised this year, plus a couple of photos that I found of the 4th instar caterpillar and a cocoon on a leaf. When the adult moth emerged (eclosed), Gail placed it outside on a tomato plant container. By the very next morning, a male had already found the female and they were mated on the container just below the tomatoes and marigolds! Hooray! Slideshow below.

Daytime Moths? Yes!

Over years of working on the blogs, I discovered that moths are often out and about during the daytime too. It’s easy to mistake them as a butterfly at first. So watch the antennae when you see a flutter on a summer walk. You might be sharing some time with a moth!

Some butterflies can look very much like moths – especially the skippers which tend to have stout bodies in shades of brown. But look at the antennae and you can generally tell if they’re moths. Male moths have long, feathery antennae for receiving the female’s scent pheromones at great distances and the females have narrower, comb-like antennae. Some moths also have long antennae that taper to point. Butterflies more commonly have straight antennae with either a hook or a flattened knob at the end. Check out the differences below.

A Dozen Moths that Challenge Those “Boring, Brown Moth” Stereotypes!

Now admittedly, many moths look rather plain and brown moths. But for this slideshow, I chose moths that demonstrate the amazing diversity and beauty of moths we have locally here in Oakland Township. Some of them Ben or I have seen as daytime adults. Others we’ve seen only as caterpillars – but that means the adults might show up in late afternoon or evening. So for photos of the adult, nocturnal moths that we haven’t seen, I thank the generous photographers at iNaturalist and Wikimedia Commons for enriching my enthusiasm for moths!

So Much for the Idea of Only Boring, Brown Moths!

I hope I’ve persuaded you that moths are much more impressive than most people think. Their young provide a foundational part of every food web in the world. They pollinate flowers and feed denizens of the night while humans sleep. When we’re lucky enough to see them, their caterpillars are strange, colorful and in many cases gifted weavers. The adults can be strangely beautiful, almost otherworldly.

But moths need help. When I was a child, a porch light shining or a car parked with its lights on would quickly draw a large cloud of moths. People put insect shields on the grills of their cars to protect them from moths. Even in the 1970’s, my two-year-old stepson could gasp and excitedly call out “A moth!” when he saw one on a window while we baked cookies in the late afternoon. But now both day and night are not as much aflutter.

Insects populations, including moths, are in steep decline and we cannot do without them. They are an integral part of sustaining the habitat in which we live. Maybe we could turn off those outside lights which make moths an easy target for predators. Or we might choose to avoid using broad-spectrum insecticides. We can teach children to be curious about “bugs,” rather than fearing them. Perhaps we could make choices that reduce the threat of devastating changes in our climate. And it’s within our power to restore in our yards, neighborhoods and parklands the native plants that these creatures and so many others evolved to eat and use for shelter. We can each take action in our own way.

Winter frequently gives me a chance to explore some group of creatures in more detail. And every time I do, I’m in awe at the complexity and beauty that’s surrounded me all my life that I’m just now discovering. The closer I look at nature, the more it ceases to be simply a landscape, a backdrop for my human life. Instead I see nature trying to maintain the intricate, interlocked system of millions of beings that evolution created through tiny adaptations over millions of years. I feel like I’m embedded within that system. What a gift to be part of and at the same time, a witness to that astounding process!

Thank you for being here sharing my discoveries and enthusiasms. It’s much more fun with you along!