The Oblique-lined Tiger Beetle, Cicindela tranquebarica, occurs across North America. Thirteen very localized poplulations that differ in color and size are currently recognized as subspecies, though they may hybridize where populations overlap. The only named subspecies known to occur in Western Washington is Cicindela tranquebarica vibex. According to A Field Guide to the Tiger Beetles of the United States, 2ed, “This subspecies is much rarer west of the Cascades and occurs in habitats such as sea beaches, mud flats along lakes, ponds, streams and irrigated pastures.” The only similar-looking Tiger Beetle, the Pacific Coast Tiger Beetle, is restricted to ocean coast beaches (see Insect menu). The characteristically variable white markings (maculations) on the elytra (hind wings) sometimes make it possible to identify individuals in this species in photos.

All of these photographs, and the brief video, were shot on May 2, 2018 at the beach south of Port Williams County Park, Sequim, Washington. The area where we took the photos is a small peninsula with the salt-water Sequim Bay on the east side and a brackish marshy area on the west. The beetles were most abundant on a sandy trail well above the (eastern) tide line, with sparse grass. A little farther to the north lies fresh-water marsh on the west.

In the same location, mixed in with Cicindela tranquebarica vibex, we saw a few Oregon Tiger Beetles, Cicindela oregona.

We made this identification using A Field Guide to the Tiger Beetles of the United States, 2ed. and the identification was confirmed by one of the authors.