Summary ⁴

The Pale Swallowtail or Pallid Swallowtail (Papilio eurymedon) is a relatively common swallowtail butterfly found throughout much of the western United States. It is found on the Pacific coast from northern Baja California to southernmost British Columbia and inland to New Mexico and the Black Hills of South Dakota. It is present from the coast to western Montana and Wyoming to northern New Mexico. It is absent from most of Nevada and western Utah. It prefers open woodlands and forest clearings, especially near permanent bodies of water such as ponds, but also urban parks and occasionally is seen in suburban areas. Though not as common as the Western Tiger Swallowtail, the Pale Swallowtail can be seen in large numbers at puddling parties where up to a dozen or more males may be seen gathered. There they join other species to sip water from damp soil to obtain nutrients for mating. Their appearance is quite similar to that of the Western Tiger Swallowtail except they are a white-cream color or very pale yellow. Some Pale Swallowtails also have differing amounts of red-orange patches on the wings just above the tail as well as on the . Tiger stripes and borders are thicker than those of Western Tiger Swallowtails. The wingspan is typically 3.5 to 4.5 inches.

Life cycle ⁵

The egg is yellowish green, round and smooth, developing a pink tinge along the sides several days after being laid (Guppy & Shepard 2001). Larvae are similar to those of other species in the tiger swallowtail group (Layberry et al. 1998); young larvae are black with a white saddle, resembling bird droppings, while mature larvae are bright green with a whitish underside, and have a pair of yellow and black eyespots on the mid-thoracic segment (Guppy & Shepard 2001). The pupae are green or brown, with darker longitudinal lines (Guppy & Shepard 2001). Adult males patrol forest edges and watercourses in search of females, and (unlike the other tiger swallowtails) also congregate at hilltops to await females (Layberry et al. 1998). Males form mud-puddling congregations (Layberry et al. 1998).

Sources and Credits

1. (c) Franco Folini, some rights reserved (CC BY), http://www.flickr.com/photos/78425154@N00/2133637786
2. (c) Ken Schneider, some rights reserved (CC BY-NC), uploaded by Ken Schneider, http://www.flickr.com/photos/zonotrichia/7328109868/
3. (c) Jon. D. Anderson, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/jon_d_anderson/9541384565/
4. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Papilio_eurymedon
5. (c) University of Alberta Museums, some rights reserved (CC BY-NC), http://eol.org/data_objects/23143324

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• BugGuide
• Butterflies and Moths of North America
• CalPhotos
• CUIC Insect Images
• Global Biodiversity Information Facility (GBIF)
• HOSTS - a Database of the World's Lepidopteran Hostplants
• Moth Photographers Group
• NatureServe Explorer 2.0
• Pacific Northwest Moths

Range Map

(c) Megan McCarty, some rights reserved (CC-BY-SA)

iNat Map