22 BULLETIN UNIVERSITY OF MONTANA. 



THE RUTULUS BUTTERFLY. 



Papilio rutulus, Boisduval. Fig. 18. 



Fig. 18, Papilio rutulus. 



Butterfly It resembles P. daunus in color and markings, but the 

 black bands are broader and it has not the two decided tails. The 

 marginal spots on the under side of the fore wings run together, forming 

 a continuous band. Expanse, male, 3.50-4.00 inches; female, 3.75-4.25 

 inches, 94 to 106 mm. 



This species also closely resembles P. turnus, and displaces turnus 

 on the Pacific Coast. It is not uncommon. At Missoula it flies as early 

 as May 10. At Swan lake it is abundant in June. It is found as high as 

 6,100 feet at Missoula. 



Food It feeds on alder and willow, which are very abundant along 

 all Mountain streams. 



Distribution It is a Pacific species. Found throughout the western 

 part of the state. Not reported at Miles City, except as mentioned under 

 daunus. Brandegee reports it from Helena. It is fairly common at Boze- 

 man, according to Cooley. 



