Underwing Moth we believe

Subject: Largish Moff in Michigan
Location: SE Michigan
August 20, 2017 2:53 pm
Hello Doc,
I found a big moth on my van’s window frame today. That’s a good indicator of scale, right? I bet it was close to 1 5/8″ long. Do you know the Type?
Signature: -Eric B.

Underwing, we believe

Dear Eric,
We believe this is an Underwing Moth in the genus Catocala, and based on this BugGuide image, it sure looks like The Sweetheart,
Catocala amatrix.  The bare spot on the thorax is a good indication that this is an older individual.  Underwings are so named because their upper wings blend in with tree bark when they are at rest, and if disturbed, they flash often brightly colored underwings, like in this BugGuide image.  Then when the moth comes to rest again and vanishes, it evades getting eaten because any sharp-eyed predator will be looking for much more brightly colored prey.  According to BugGuide:  “larvae feed on leaves of several species of poplar (Populus spp.) and Black Willow (Salix nigra).”

Leave a Comment