Subject: Oak Moth?
Location: Yorkville, CA
May 25, 2014 9:19 am
I am in northern California and saw this moth yesterday in the early evening. Is it fully developed? Is it an oak moth?
Signature: Margot
Dear Margot,
This is not an Oak Moth. It is a Sphinx Moth or Hawkmoth in the genus Smerinthus. Historically, we would have identified this as a One Eyed Sphinx, Smerinthus cerisyi, but recent taxonomical changes have recognized a new species on the West coast with no common name, Smerinthus ophthalmica. According the the Sphingidae of the Americas: “Smerinthus ophthalmica, (forewing length: 34-47mm) closely resembles Smerinthus cerisyi, and until recently (2010) had been synonymized with cerisyi. … S. ophthalmica flies across southern British Columbia and southern Alberta into southwestern Saskatchewan. In the United States it can be found in Washington, Oregon and northern and central California eastward into Idaho, western Montana, western Wyoming and northern Nevada and northern Utah. … It is impossible to distinguish female ophthalmica from female cerisyi without examination of DNA, but male ophthalmica are noticeably distinct: the forewing outer margin of ophthalmica is smoothly scalloped while that of cerisyi is more sharply/irregularly scalloped; the lower edge of the grey apical patch in ophthalmica runs almost straight to the first vein, while in cerisyi the same edge is notched with a slight return toward the outer margin; the pm line of opthalmica consists largely of two diffuse arcs while the same line in cerisyi is a series of shadowed projections; the pink suffusion on the hindwing of ophthalmica is more reduced (tanner) toward the outer margin than in cerisyi.” The lavae of both species feed on the leaves of willow, aspen and cottonwood, not oak.