Sunday evening, August 18, 2019, my husband took me to a lovely Farm to Table dinner at Sweet Earth Farm, San Juan Island, WA http://sweetearthfarm.com/products/farm-events/ Aside from the amazing food and beautiful scenery, I got to sit at a table with some really great folks who, after finding out about my love of bugs, sent me a photo of a Tiger Moth that was on the side of their garage door. Turns out this particular moth was going to be pretty interesting!
As I worked through my usual steps to ID the specimen, I noted the photo came to me with “Ornate Tiger Moth” in the subject line. This specimen was indeed very similar to the Ornate Tiger Moth (Apantesis ornata). To complicate things a bit more, not only has this family of moths (Tiger moths) been reclassified (from Arctiidae to Erebidae), but this genus has also recently been renamed. Formerly Grammia ornata, Apantesis ornata (Ornate Tiger Moth’s) have not been recorded in San Juan County and records for adult flying periods of this species are earlier than for this particular specimen. I believed this specimen was something different.
There were records of another species of Tiger Moth in the Pacific Northwest I came across that better matched the image of my photo and timing of adult emergence. Apantesis nevadensis, the Nevada Tiger Moth, has been recorded as widely distributed in the Pacific Northwest, but according to information on Pacific Northwest Moths http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-arctiinae/tribe-arctiini/apantesis/apantesis-nevadensis/, A. nevadensis is “only found in a few locations west of the Cascade Mountain crest, including on Vancouver Island, the south Puget Sound, and coastal Oregon.”
However, a fairly recent (2007) review in Zootaxa by Ferguson and Schmidt described a subspecies of Apantesis nevadensis, A. n. superba that had been recorded on Vancouver Island, B.C., our neighbor. Could the San Juan’s be a new geographical locality for this subspecies?
I emailed the photo to Merrill A. Peterson at WWU. He has a great book available called Pacific Northwest Insects too. You can find it here ~ (https://pacificnorthwestinsects.com). Merrill is Professor and Chair of Biology and Insect Collection Curator at Western Washington University and my all around go-to person for confirmation of insects in our region. Merrill agreed that my ID was correct. Since this was a FIRST record for the San Juan’s, he asked if I could collect locality (GPS) data and date of sighting from the original photographer.
My next task was to email the gentleman who sat with us that night at dinner and ask him if he was willing to share this, enabling Merrill to post the record online. We needed first initial, last name, GPS data, and date of sighting. Not only did I receive a response with this information AND permission for me to use the photographs in my blog, but I received a photo of a second moth taken the very day this gentleman went out to register the GPS coordinates on his phone. Now we have a record of two sightings, almost exactly one year apart!
So how exactly can you tell the Apantesis nevada from Apantesis ornata?
Here are the morphological descriptions for adult specimens of each species, taken from http://www.bugguide.com to get you started. Please feel free to contact me here or at https://www.facebook.com/buggingyoufromSJI/ with questions or to report sightings of insects in the San Juan’s. 🐛🐞🦋🐜🐝🦗
Apantesis ornata ~
Adult: FW appear black, typically with a net-like pattern of extensive yellowish or rosy off-white transverse lines and thinner pale veins. HW color is variable from yellow-orange, orange, to orange-red, rarely entirely black. HW is heavily marked with black, including the basal wing, multiple spots, and an irregular marginal band. These are often fused to each other, especially near the wing margin.
Apantesis nevada ~
Adult: forewing black with 3 variably thin to wide pale bands crossing wing; subterminal line W-shaped, touching PM line at top of W, and outer margin at bottom; single pale line from base of costa to anal angle; hindwing varies from bright red with several black spots to pale pink with merged spots forming extensive black area; top of thorax white with 3 longitundinal black stripes; ptagia (collar) has one black spot on each side
If you’re interested in learning more about these and other species of moths, or have a sighting to report, you can visit Pacific Northwest Moths at http://pnwmoths.biol.wwu.edu. To see locality records for Apantesis nevadensis, including the first record(s) of this moth for the San Juan’s, you can link here ~ http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-arctiinae/tribe-arctiini/apantesis/apantesis-nevadensis/
Ferguson, D. C. and C. Schmidt. 2007. Taxonomic review of the Grammia nevadensis species group (Lepidoptera: Arctiidae) with descriptions of two new species, Zootaxa 1405, pp. 39-49: 42-44.
Pacific Northwest Moths 2018. Apantesis nevadensis. http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-arctiinae/tribe-arctiini/apantesis/apantesis-nevadensis/
Peterson, M. 2018. Pacific Northwest Insects. Seattle Audubon.
Powell, J.A. and P.A. Opler. 2009. Moths of Western North America. University of California Press.