In general, I think people should be talking more about moths. In the Lepidoptera order, more than 90% of species are moths, and less than 10% are butterflies. Plus, moths have remarkable variety in body type, wing shape, and antennae form. The easiest way I know of to tell them apart is that butterflies all have knobs on the end of their thin antennae, whereas moth antennae can have many crazy and wonderful variations, but no knobs.
This week’s moth is in a genus named for the shape of its antennae: the Red-shouldered Ctenucha Moth. Pronounced “ten-OOCH-ah,” the root word means “combed.” Others in the Ctenucha genus have wing veins outlined in white or orange, which, coupled with the metallic blue body, mimics a spider wasp. But only this west coast moth has a muppet-like red face.
This day-flying moth would challenge any insect in a beauty pageant, but there’s surprisingly little information about the Red-shouldered Ctenucha. The Virginia Ctenucha, which has a larger range, has been more studied. It’s one of a few moths that has “ears” to detect bats, and also a sound-producing organ on the thorax to jam the predators’ echolocation. Although they are diurnal, Virginia Ctenucha moths are also active at night. Someone should stalk our local moths to see if they party after dark as well.
Ctenucha rubroscapus are in the Tiger Moth family, and the caterpillars are fuzzy like woolly bears — they have a base of black hairs with longer, white tufts. See the link below to view some awesome pictures of caterpillars, cocoons, and newly-pupated Virginia Ctenuchas. They seem to weave their hair into the cocoons!
I saw just this one moth at Mount Pisgah but I’ve seen dozens of them at the Oregon Coast as well. Keep your eyes open for this brilliant insect!
Life cycle pictures of Virginia Ctenucha: https://www.buglifecycle.com/?page_id=2377. Accessed 7/5/21.
Fullard and Dawson 1999 research on diurnal moth ears: https://www.researchgate.net/profile/Jeff-Dawson-4/publication/226450427_Why_Do_Diurnal_Moths_Have_Ears/links/0a85e53c966563bc1d000000/Why-Do-Diurnal-Moths-Have-Ears.pdf. Accessed 7/5/21.