Hodges#7829

Pachysphinx occidentalis

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Lepidoptera
Superfamily: Bombycoidea
Family: Sphingidae
Subfamily: Smerinthinae
Tribe: Smerinthini
Genus: Pachysphinx
Species: occidentalis

Pronunciation

How to pronounce Pachysphinx occidentalis: //ˌpækɪˈsfɪŋks ˌɑksɪˈdɛntəlɪs//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Pachysphinx occidentalis ova by Whitney Cranshaw, Colorado State University, Bugwood.org. Used under a CC BY 3.0 us license.

Hugemoth july2009 3 by Are you ready for IPv6? (talk). Used under a Public domain license.

Pachysphinx occidentalis larva by Whitney Cranshaw, Colorado State University, Bugwood.org. Used under a CC BY 3.0 us license.

Pachysphinx occidentalis BMNHE813704 female un by The Trustees of the Natural History Museum, London. Used under a CC BY 3.0 license.

Hugemoth july2009 2 by Are you ready for IPv6? (talk). Used under a Public domain license.

Pachysphinx occidentalis BMNHE813704 female up by The Trustees of the Natural History Museum, London. Used under a CC BY 3.0 license.

Summary

Pachysphinx occidentalis, also known as the big poplar sphinx, is a moth first described by Henry Edwards in 1875. It inhabits riparian areas and is distributed throughout western North America. The larvae are known to feed on cottonwoods and willows.

Physical Characteristics

Wingspan 130–150 mm; forewing length 6.5-7.1 cm; two color forms: pale yellow-brown forewings for the light form and dark gray for the dark form; hindwings have a crimson patch and two dark lines near the anal angle.

Identification Tips

Light form forewing is pale yellowish-brown, dark form is similar to Modest Sphinx (Pachysphinx modesta) but with darker contrasting lines.

Habitat

Riparian areas, open parklands, suburbs at low elevations.

Distribution

Western United States from North Dakota to Texas, westward; occurs in Alberta, Canada.

Diet

Larvae feed on leaves of cottonwoods (Populus spp.) and willows (Salix spp.); adults do not feed.

Life Cycle

Adults are nocturnal, flying from February to September in lower elevations of southern California and southern Arizona, with up to three broods; one generation per year in northern regions, adults present from June to August.

Reproduction

Overwinters as a pupa in the soil.

Similar Taxa

Pachysphinx modesta

Misconceptions

Confusion exists regarding the common name, as both P. modesta and P. occidentalis have been referred to as the Big Poplar Sphinx.