BIG POPLAR SPHINX / PACHYSPHINX OCCIDENTALIS

The Big Poplar Sphinx (Pachysphinx occidentalis) is a moth of the Sphingidae family. It lives throughout Canada and the United States. The habitat consists of riparian areas and suburbs.

Pachysphinx occidentalis is one of our largest moths . The wingspan is 130–150 mm and has light olive-gray or olive-tan forewings and dark wine-red hindwings with a black and blue mark at the anal angle. The forewing outer margin is strongly and evenly scalloped. The wing base medial to the median line is a light shade of the ground color, the lateral median area is dark olive, and the outer wing is intermediate with various shades of blue-gray and olive between the lines. The median line is nearly perpendicular to the base, with teeth lateral on the veins. The postmedial line has several components, all gently scalloped. The discal spot is relatively small, yellowish white without a darker outline. The anterior and central hindwing is wine red, most vivid at the base. The medial and posterior portion is light tan with a large black and light blue mark at the anal angle. The black portion of this mark is divided into two nearly equal intensity anterior and posterior transverse lines. The head and thorax are olive-gray. The antenna is club-like.

This species is widely distributed in the Pacific Northwest east of the Cascades, but is very narrowly restricted to riparian or urban habitats along creeks or rivers in low elevation desert regions.