24 



BULLETIN UNIVERSITY OF MONTANA. 



BRUCE'S SWALLOWTAIL. 

 Papilio brucei, Edwards, Fig. 20. 



Fig. 20, Papilio brucei. 



Butterfly Expanse 3.25-3.60 inches. Under surface yellow, with 

 black borders ,the same as in P. daunus. The base of the wings is black 

 and it extends in such a way as to make the discal cell appear black with 

 three yellow bars. It has the yellow spots in the black along the costa. 

 It has one tail, and black marking on the veins. The last lunule in the 

 hind wing is orange with a black ocellus. The hind wings have the blue 

 clouds. The body is black. It is thought to be the result of a union be- 

 tween P. oregonia and P. bairdi. 



Food The caterpillar feeds on Umbelliferae, and is common on 

 parsley and parsnips in gardens. 



Distribution In Colorado and adjacent regions P. oregonia meets 

 with the form bairdi which ranges northward from Arizona. Hybridiza- 

 tion is thought to have occurred, resulting in the fixed form brucei, 

 breeding either toward bairdi or oregonia. Oregonia is found in Oregon 

 and Washington, where bairdi is absent. We formerly captured a speci- 

 men identified by Edwards as oregonia and another as bairdi near Idaho 

 Falls, which lends support to the hybridization idea. We have sought for 

 oregonia in Western Montana, but have found none which could be so 

 called. Most of our specimens have been taken from Missoula. One was 

 taken in the Mission mountains. Cooley has specimens from Bozeman, 

 thought to be zolicaon. Possibly Wiley's zolicaon may be brucei. 



