by Skip Via
skip@westvalleynaturalists.org
Note: Click to enlarge photos.
It’s always fun to run across a species that you have never encountered before, and that was the case for me today when I observed this Western Sheep Moth while I walking the trails in Happy Valley.
Western Sheep Moths are native to the western US. Their main range is southern California and the Sierra Nevada mountains, and while they are not common here in the valley, there are several reports on iNaturalist of encounters with them in our area.
Unlike many moth species, Western Sheep Moths are daytime flyers, and rather large as local moths go–a bit smaller than a Luna Moth with an average wingspan of roughly three inches. Their identifying characteristics include pink, orange and yellow wing spots, black and yellow striped abdomen, prominent feathery antennae, and a tuft of bright yellow fur across the top of the thorax.
Western Sheep Moths lay their eggs in the summer months on roses (Rosaceae), both wild and cultivated. Their caterpillars (larvae) feed on them. They are also known to feed on buckthorns, an invasive species here in Montana. While they are not important pollinators, they are known to inadvertantly serve this function.
Why are they called Sheep Moths? It turns out that they can be pests for sheep farmers, as adults will feed on the wool of domesticated sheep, degrading the quality and quantity of the wool. Sheep moths can cause a 15% drop in the quantity of wool produced by a flock.They are also known to invade homes and feast on wool and other clothing. They are prey for many birds species, and they are known to eat some insects.
Have you encountered a sheep moth in your wanderings? Do you see them as pests? Part of the ecosystem? Let me know in the comments.
