Kristi discovered a Polyphemus outside her home, while Rose found one downtown outside A Carousel for Missoula. This is our most widespread silkmoth in the US. It is also one of our largest, with a wingspan of up to 6 inches. Like our other giant silkmoths, males have smaller bodies but much larger and more feathery antennae than do females (males are pictured here). When they emerge as adults, they don’t have functional mouthparts …meaning they don’t feed. They live for a week to two weeks tops, so it’s basically a race to mate. Here in western Montana they can be found mostly in May and June. Larvae feed on leaves of broad-leaved trees and shrubs, including chokecherry, birch, maple, willow, and members of the rose family.
Top photo by: Kristi DuBois on 6/3/21 in Missoula, MT
Bottom photo by: Rose Marchak on 6/5/21 in Missoula, MT