Similar Species: The Pale Swallowtail (Papilio eurymedon) is similar. Western Tiger may appear yellow with black while Pale appears black and white. Also the black stripes on the Pale are thicker and deeper.
Habitats, Behavior: among the willows.
Larval Foodplants: California Sycamore (Platanus racemosa) . Cottonwood (Populus spp.) and willow (Salix spp.)