Butterflies, moths: What’s the difference?

A hummingbird clearwing moth on some bee balm.

By Jeanne Church

I had never given much thought to the differences between butterflies and moths (collectively known as lepidoptera) before taking pictures of them and actually seeing the differences myself.

For most of my life, I had just assumed that all the large, beautifully colored lepidoptera flitting around gracefully among the flowers were butterflies, and all the small drab-looking ones were the creatures my grandmother tried to deter from eating her clothes by hiding mothballs in her dresser drawers!

My childhood “theory” about the differences between butterflies and moths began to unravel when I started taking pictures of small, moth-like insects that turned out to be butterflies and large, colorful “butterflies” that turned out to be moths. It got me thinking: What’s the difference?

The first website I came across said, “One of the easiest ways to tell the difference between a butterfly and a moth is to look at the antennae.” That little tidbit of information would only be helpful, I thought, if you were able to get a picture of the insect or actually catch it! “A butterfly’s antennae” it went on to say, “are club-shaped with a long shaft and a bulb at the end. A moth’s antennae are feathery or saw-edged.”

As I read further into the article about butterflies and moths, I discovered that I had gotten at least one thing right as a child: “Butterflies are typically larger and have more colorful patterns on their wings. Moths are typically smaller with drab-colored wings.” The keyword in these sentences is “typically”. There are always exceptions, and I have found them!

For me, the best example of a butterfly that could be mistaken for a moth is the cabbage white. It’s a small, white, non-descript butterfly that flits around everywhere during the spring and summer and seemed like a moth to me! Recently, I came across a beautiful black and white polka-dotted lepidoptera with orange “fluff” on its legs that I thought must be a butterfly. It was an eight-spotted forester moth!

One difference that doesn’t require a camera or a magnifying glass has to do with wing positions at rest. “Butterflies tend to fold their wings vertically up over their backs. Moths tend to hold their wings in a tent-like fashion that hides the abdomen.” The critical word here is “tend.” Butterflies don’t always hold their wings vertically and moths don’t always hold their wings in a tent-like fashion. It’s not fool-proof!

One of my most surprising discoveries was a moth that looked like a hummingbird! There are at least three hummingbird moth species in Michigan and the one you’ll see most often is the hummingbird clearwing. It has a stocky little body with transparent wings and it hovers in front of flowers just like a hummingbird; unfurling its tongue into the flower to sip nectar. You’ll most often find hummingbird moths on bee balm, phlox, butterfly bush, honeysuckle and verbena, as well as other flowering plants.

Except for the unique hummingbird moths, it isn’t always easy to tell whether the lepidoptera you’re looking at is a butterfly or a moth, but it’s always an interesting challenge! Even scientists, whose job it is to study these fascinating insects, find that the distinctions between the two are becoming more and more blurred.

Enjoy your discoveries!

Follow Jeanne at picturewalks.org

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