Early Stages.—Both the caterpillar and the chrysalis show a very strong likeness to those of P. asterias. The larva feeds on umbelliferous plants.
The range of the species is confined to the extreme northeastern part of our faunal territory.
(14) Papilio bairdi, Edwards, Plate XL, Fig. 2, ♂ (Baird's Butterfly).
Butterfly.—This form, the male of which is represented in the plate, is the Western representative of P. asterias, and is characterized in general by the fact that the size is larger than that of asterias, and the postmedian band of yellow spots is broader. The female is generally darker and larger than that sex in asterias. Expanse, 3.25-3.50 inches.
Early Stages.—Not unlike those of P. asterias. The caterpillar feeds upon Umbelliferæ.
The seat of this species or form is Arizona, whence it ranges northward.
(15) Papilio brucei, Edwards, Plate XL, Fig. 4, ♂ (Bruce's Butterfly).
Butterfly.—This species, which is thought to be the result of a union between P. oregonia and P. bairdi, is found in Colorado. Oregonia is, unfortunately, not represented in our plates. It flies in Oregon and Washington, where P. bairdi is not found. In Colorado and adjacent regions meeting with the form bairdi, which ranges northward from Arizona, hybridization has occurred, and we have a fixed form breeding either toward bairdi or oregonia. To this form, characterized by more yellow on the bands of the wings than in P. bairdi, and less than in oregonia, Mr. Edwards has applied the name P. brucei, in honor of Mr. Bruce of Lockport, New York, who has done much to elucidate the problems connected with the species. Expanse, 3.25-3.60 inches.
Early Stages.—These have been fully described by Edwards. They are much like those of asterias, and the food-plants belong to the same class.
Bruce's Butterfly is found quite abundantly in Colorado.