Species Hyalophora euryalus - Ceanothus Silkmoth - Hodges#7770

7770

Hyalophora kasloensis

EURYALUS: from the Greek "eurys" (broad) + the Latin "ala" (wing)

Wingspan 89-127 mm

Adult: overall similarity to Columbia Silkmoth and Cecropia Moth except area beyond PM line maroon, purple, or pinkish, in a broad diffuse band; discal spot on hindwing shaped like an elongated comma pointing toward outer margin, sometimes breaking PM line

Larva: changes colors as it develops and molts; mid instars are the most brilliantly colored with nine pairs of dorsal yellow spines, the first three pairs with partial to complete black rings; a middorsal yellow spine on A8; two rows of lateral blue spines tipped with white along T1-A8; white-tipped blue spines also occur on the head, at the base of the true legs, and in the anal region; body ranges from green to whitish-green

later instars whitish-green with white spines

[adapted from description by Jeffrey Miller]

British Columbia to western Montana, south through west coast states to Baja California. In California, found mostly west of the Sierras.

coastal areas, chaparral, intermontane valleys, conifer forests

adults fly from January to July, depending on altitude, latitude, and seasonal variation

larvae in July and August

Larvae feed on a number of trees and shrubs, including Red Alder (Alnus rubra), birch, Antelope Bitterbrush (Purshia tridentata), buckthorn (Rhamnus), Buffaloberry (Sheperdia canadensis), Ceanothus species, cherry, gooseberry (Ribes), Hardhack (Spiraea douglasii), hazel, Madrone (Arbutus menziesii), manzanita (Arctostaphylos), Mountain Mahogany (Cercocarpus betuloides), Mountain Maple (Acer glabrum), rose, Saskatoon Serviceberry (Amelanchier alnifolia), willow (Salix), and occasionally Douglas-fir (Pseudotsuga menziesii).

eggs laid singly or in clumps on leaves of host plant, hatching in 9-14 days; overwinters as a pupa in teardrop-shaped cocoon attached to twig on outer part of host plant

The range of Hyalophora euryalus overlaps H. columbia (and its subspecies H. c. gloveri); some hybridization may occur where the two species meet.

Columbia Silkmoth and its subspecies Hyalophora columbia gloveri has no maroon or purplish shading beyond PM line of wings, and the discal spots on its hindwing are not as elongated (compare images of both species).

Cecropia Moth has more gray in the basal half of the wings, the reddish band beyond the PM line is narrow and sharply defined (not broad and diffuse), and the discal spots on its hindwing are not elongated (compare images of both species).

Miller and Hammond, #235, p. 108 (1)

Tuskes et al., pp. 211-213, plates 28--adult, 6--larva, fig. 43--cocoon (2)

Powell and Hogue, p. 228, plate 11d--adult, 11e--larva (3)

Butterflies and Moths of North America - adult and larva images, description, flight season, food plants, biology, habitat, references, US distribution map (Opler, Paul A., Harry Pavulaan, Ray E. Stanford, Michael Pogue, contributors)

Caterpillars of Pacific Northwest Forests and Woodlands - live larva image, description, food plants, seasonality (Jeffrey Miller; USGS)

live images of all life stages plus description and comments (Jeremy Tatum, Butterflies and Moths of Southern Vancouver Island)

live images of all life stages (Peter Bryant, Moths of Orange County, U. of California at Irvine)

live images of all instars and all life stages (Kirby Wolfe, California)

live adult image plus description, food plants, biology, distribution (G.G. Anweiler, U. of Alberta)

food plants plus synonyms, links, references (Markku Savela, FUNET)