While watering my peonies early one morning I noticed a mating pair of sphinx moths clinging to a peony stem (Modoc County CA). Even when I gently repositioned the stem for photographs, the moths did not fly. They remained in the same spot throughout the day and were still there when I stopped checking for the night. Early the following morning the two moths were gone.
These are Smerinthus ophthalmica moths. Until 2010 S. ophthalmica was considered synonymous with Smerinthus cerisyi or the one-eyed sphinx moth. Since then S. ophthalmica is considered a separate species occurring in the American West from British Columbia and Southern Alberta, through Washington, Oregon and California to near the Mexican border. S. cerisyi is the northern and eastern species.
“Opththalmica” (I do not know a specific common name for this species.) is a large, heavy bodied moth with highly variable coloration. Its base color is usually grey or grey brown but may be tan or dark brown. The forewings have a complex pattern of light and dark brown while the hindwings are rose-pink shading to tan on the margins. The outer margins of ophthalmica’s forewings are smoothly scalloped. The bright blue circle (looks whitish) centered on a large black spot on the anal angle of the hindwings is an identifying characteristic of both cerisyi and ophthalmica.
S. ophthalmica flies at night. The female, shortly after eclosing (emerging from the pupal case) during the night (often around midnight) extends a scent gland from the posterior of her abdomen to attract a male. During mating the male aligns himself at 180° from the female so their heads face in the opposite direction. Pairing continues until the following night.
Ophthalmica is a common moth that can be found in a variety of habitats – urban, coastal, mixed deciduous forests, conifer forests, near streams in deserts – anywhere there is enough moisture for the willows and poplars on which the larvae feed. Adult S. ophthalmica moths do not feed.