Ceanothus Silkmoth

Not applicable for Alberta.

The Ceanothus Silkmoth occurs in the dry intermontane valleys and interior of BC (as far north as Prince George along the Fraser River) south to Baja California. The only AB record of this species is for a live specimen introduced along with a shipment of ornamental shrubs from Oregon to Red Deer (E. Mengersen, pers. comm.). There is a small possibility this species is present in the Waterton / Castle River area of AB.

This species can be recognized by the pinkish maroon colour that prevails beyond the postmedian white band. In H. columbia gloveri, this outer third of the wing has very little or no trace of maroon. Although variable, the discal spots are usually greatly elongated towards the outer edge of the wing, and this trait distinguishes euryalus from the other species of Hyalophora. The range of euryalus is not known to overlap with any other Hyalophora in Canada.

There are no known native populations in AB. See remarks under "Range".

Overwintering cocoons of H. euryalus are attached to the larval host plant and occasionally other plants.

Larvae are reported to feed on a variety of shrubs including Red Alder (Alnus rubra) (which occurs only along the west coast of BC), willow, wild rose, Currants and gooseberries (Ribes spp.), buffaloberry (Sheperdia canadensis), Mountain Maple (Acer glabrum), Saskatoon (Amelanchier alnifolia), and Redstem Ceanothus (Ceanothus sanguineus). Larvae also occasionally feed on Douglas Fir (Pseudotsuga menziesii).

Hyalophora euryalus, the ceanothus silkmoth, is a moth of the family Saturniidae. It is found in the dry intermontane valleys and interior of British Columbia, Canada, (as far north as Prince George along the Fraser River) south to Baja California in Mexico. The species was first described by Jean Baptiste Boisduval in 1855.

The wingspan is 89–127 mm. Adults are on wing from January to July depending on the location. There is one generation per year.

The larvae feed on Ceanothus, Rhamnus californica, Prunus emarginata, Arctostaphylos, Alnus, Betula, Corylus, Ribes, Pseudotsuga menziesii, Arbutus menziesii, Liquidambar and Salix.