Roads End Naturalist

Exploring the natural world as we wander at the end of the road


Moth Majesty

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There are two worlds; the world of sunshine, and the world of the dark. There are whole armies of living things , which, when we go to sleep, begin to awaken; and when we awaken, go to sleep.

~W.J. Holland

It happened again the other night. When I started to close the inside door for the night, there were a few moths clinging to the screen door. Most were small and dark, the LBT’s (little brown things) of the insect world that make mothing so challenging. But one was majestic, royal, magnificent.

imperial Moth, male, underside
A male Imperial Moth staring at me through the screen door (click photos to enlarge)

It was one of the large silk moths, an Imperial Moth, Eacles imperialis. These beauties have wing spans of 4 to 5.5 inches, and are reported to be seen in the south from April to October, although I usually see them in mid- to late summer.

Imperial Moth, male
Imperial Moth, male

Females are larger and more yellow in color than males, so this one’s color pattern, with large blotches of purplish-brown on the upper wings, identified it as a male. Most references say they have but one generation per year, although Bug Guide says there may be two in the south. They overwinter as a pupa underground, emerge, and fly about for a couple of weeks (the adult moths do not feed), mate, and die.

Imperial egg
Imperial Moth egg, about to hatch

Females lay large eggs, singly, or in small groups, on a variety of trees including elm, hickory, oak, sweet gum, and pines. A couple of years ago, I had a large, gravid female, come to a light. I held her overnight in a paper grocery bag where she laid a number of eggs inside the bag. She was released the next morning. I cut out strips of the bag containing eggs and clipped them to several potential host plants in the yard and watched the caterpillars hatch and grow.

Imperial moth early instar
Imperial Moth caterpillar, early instar

Young larvae have prominent spikes which become less pronounced as they molt and grow.

Imperial eating
Imperial Moth caterpillars grow to be almost 4 inches in length and can vary in color

Later instars can range in color from green to brown to orange-ish, and grow to be almost 4 inches in length. They lose the large spikes, but are covered in fine “hairs”. When finished eating and growing, they bury themselves in the soil and pupate, spending the winter underground.

Imperial Moth, male 1
Imperial Moth in all its glory

When they finally emerge, they are one of our most beautiful moths, and bring joy to any who are lucky enough to see them in their brief time in our night sky.

 

 

 

 

 

Comments

4 responses to “Moth Majesty”

  1. Petra Avatar
    Petra

    What a beauty! And such cool caterpillar pictures. Really like the green image when it is bigger already.

  2. Don Avatar
    Don

    Imperial Moth egg!! Fantastic

  3. Anthony Hendricks Avatar
    Anthony Hendricks

    I found one of these moths yesterday! In Wisconsin! Had trouble IDENTIFYING it till a friend found your post! Are they typically found in southern Wisconsin or here now due to global warming? Thanks for the help!

    1. roadsendnaturalist Avatar

      Hey Anthony, glad to help. They are one of my favorite moths (and caterpillars) and have a large range, in the Eastern U.S> (east of the Rockies) from Canada down into South America!

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Roads End Naturalist

Exploring the natural world as we wander at the end of the road

Copyright Mike Dunn and Melissa Dowland