Subject: Moth question
Geographic location of the bug: Orondo Wa
Time: 01:19 PM EDT
Your letter to the bugman : Can help identify this creature
How you want your letter signed: Gilbert
We believe this impressive Moth is a Western Poplar Sphinx, Pachysphinx occidentalis, which is pictured on BugGuide. According to BugGuide: “Larvae feed on leaves of cottonwoods, especially Populus freemonti and Populus sargentii, also willow (Salix spp.). Adults do not feed.” According to Sphingidae of the United States of America: “This is a large moth, forewings are between 51-71mm in length (2). The large scalloped forewings are light yellow-gray and brown with a white reniform spot. In the similar Pachysphinx modesta, the forewings tend to be a grayer color, and overall darker.” Butterflies and Moths of North America lists a Spokane, Washington sighting. Because of the timing of your submission as well as the impressiveness of the Western Poplar Sphinx, we have selected it as the Bug of the Month for July 2021.
Thanks for the quick response. It was a beautiful specimen and I enjoyed watching it for like 20 minutes or so that it was with us. Can you tell if it was male or female how does that even matter.
Hi again Gilbert,
Here is an image of mating Western Poplar Sphinxes. The female is generally larger with a thicker body. We believe your individual is a female but we would defer to an expert in the Sphingidae moths.