16(3 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



low. Coxae and femora black, tibiae yellow touched with black between the 

 spurs, tarsi sordid yellow. Forewing with opalescent areas before and 

 behind the discal mark, which is black broadly faced with red on each side ; 

 costa, outer and inner margin, and veins black; outer opalescent area 

 bordered with red between the veins at costa and before the broad black 

 outer margin ; inner margin lined broadly with bright red two-thirds of its 

 length to a point before the black wing base; fringes cupreous-black; 

 underside with a heavy shading of orange-red. Hindwing transpar- 

 ent ; wing base, costa, and margin black ; veins black, slightly touched with 

 red; vein Ic entirely red, vein lb and areas between the veins to vein la 

 red ; discal mark conspicuous, black, narrowly bordered with red. On the 

 underside, veins and inside of margin orange-red. 



Female. — Antennae simple, black above, brownish beneath. Labial 

 palpi smoother than in the male, entirely yellow. Tongue well developed. 

 Head crowned with a heavy brush, black and yellow mixed ; face bright 

 yellow. Thorax metallic black; tegulae with a yellow stripe broadening 

 to an upcurved transverse line on metathorax ; a yellow patch above and 

 another beneath at wing base. Abdomen black, segments 2, 4, 5, and 6 

 broadly banded with bright yellow above and beneath ; segment 3 dorsally 

 spotted and beneath banded with yellow ; anal tuft short and blunt, golden 

 yellow, with smaller black tufts at the sides. Legs wholly deep yellow. 

 Forewing mostly red, except costa, narrow margins, cubitus, and outer 

 veins, which are black ; small transparent areas before and behind the nar- 

 row black discal mark broadly encircled red ; a broad, red streak between 

 the cubitus and inner margin ; underside orange, discal mark red. Hind- 

 wing transparent, with costa and margins broadly bordered with red to the 

 black wing base ; discal mark black at the center and red at the sides ; vein 

 lb broad, red ; underside mostly orange-red ; fringes wide, dull black. 



Expanse : Male 18 to 20 mm., female 20 to 24 mm. 



Distribution. — Colorado, Utah. 



Type. — Female. In the American Museum of Natural History. 



This form has been considered another color variety of pyramidalis, 

 displaying wing shadings of red to a more intensified degree than is found 

 in the variety rnontana. Rearing experiments, as yet limited to one male 

 and one female, throw some doubt on this conclusion. A. p. ruhescens is 

 a root borer in Oenothera biennis and not in Chamaenerion, the only food 

 plant so far recorded for pyrarnidalis ; it averages smaller in size and, aside 

 from the more brilliant red coloration on the wings, dififers in the arrange- 

 ment of the abdominal bands, segments 4, 5, 6, and 7 in the male and 

 segments 4, 5, and 6 in the female being nearly wholly yellow, except for 

 a very narrow touch of black on the posterior edge of each. The posterior 

 tibiae of the female are wholly deep yellow, those of the male more sordid, 

 intermixed with black. Records of ruhescens, accepted as authentic, are 

 restricted to Rocky Mountain regions in Colorado and Utah. This form 

 may be entitled to recognition as a geographical race. 



