Butterfly or Moth?

by AMNH on

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In The Butterfly Conservatory, you’ll see examples of both moths and butterflies fluttering about, but how can you tell these animals apart? It can be tricky, because there are no “bright line” distinctions between these lepidopterans.

 

Monochromatically colored moth alights on the leaf of a plant.
Moths like this Pine Processionary Moth tend to be less brightly colored than butterflies, but it’s not a hard-and-fast rule!
Courtesy of Alvesgaspar/Wikimedia Commons

“Because there isn’t a single feature that absolutely distinguishes between all butterflies and all moths, the classification of species merges on a continuum,” Hazel Davies, director of living exhibits, writes in her book Do Butterflies Bite?

 

Monarch butterfly displays its patterned wings as it alights on a flower.
Butterflies like this Monarch typically rest with their wings raised above their heads. 
Courtesy of J. Werther/Wikimedia Commons

There are three characteristics that can give you a general sense of which end of the butterfly-moth spectrum a particular species leans toward.

  • Butterflies are active during the day, while most moths are nocturnal.
  • When at rest, the butterflies generally hold their wings together, above their heads. Moths, in contrast, hold their wings horizontally.
  • Check the antennae! The antennae of butterflies usually thicken at the tips, developing “clubs” of a sort at the ends. In moths, the antennae are normally straight and uniform in width, or are feathered.

 

Large moth alights on the fingers of an adult human hand.
Cecropia moths like this one are notable for their feathery antennae.
Courtesy C. Luna/USFWS

Want to put your species spotting skills to the test? Join us at The Butterfly Conservatory, open through May 28.