32 BULLETIN UNIVERSITY OF MONTANA. 



BECKER'S WHITE. 

 Pontia beckeri, Edwards. 

 Butterfly — Expanse, 2 to 2.2 inches. 51 tc 56 mm. Easily discrim- 

 inated from all other allied species by the green markings on the under 

 side of the hind wings, concentrated in broad blotches on the disk; by 

 these markings the species recalls the species of the genus euchole. 



Male. Upper side pure white; base of wings not powdered with 

 black, as in allied species; at the outer edge of the cell a dense black 

 subrectangular spot (not reaching the costa), with a central white streak. 

 Secondaries immaculate. 



Under side white; the veins at apex and on upper hind margin 

 bordered by black scales and suffused with greenish yellow; cellular 

 spot enlarged, its base broadened and posterior edge excavated. 



Secondaries have all the veins and branches yellow; those ter- 

 minating on hind margin edged by broad bands of yellow green reaching 

 to middle of disk and connected anteriorly; three large spots of same 

 color about the cell; another large triangular subapical spot on costa; 

 the veins at base banded with green; all these bands and spots slightly 

 sprinkled with black scales. 



Body above gray, yellowish beneath abdomen, white beneath thorax; 

 legs white; palpi white, grey on upper side and at tip. Antennae white 

 above and at base below, beyond brown; club black, tip pale fulvous. 



Female. Similar to male, but with larger and more numerous spots; 

 secondaries with black spots and dark streaks along the veins; under 

 side with a round black spot in submedian inter-space on primaries, in 

 addition to discal black spot. 



Early Stages — The mature larva is 1.25 inches, 32 mm. long, greenish 

 white, thickly marbled or sprinkled with gray, and v/ith a very distinct 

 orange belt between the segments; each segment also has 16 or 18 jet 

 black tubercles which taper into black bristles; the head is tinged with 

 yellow. It feeds on cruciferous plants. 



Distribution— From Washington to Central California, east to Colo- 

 rado. Taken in the state by Ccoley at Bozeman, and by Allen at Dillon. 



Genus SYNCHLOE, Huber. 



(Eucliloe-Anthocharis.) Fig. 29. 



Butterfly— Small butterflies, white in color, with the apical region of 



the primaries dark-brown, marked with spots and bands of yellowish 



orange or crimson. On the underside the wings are generally more or 



less profusely mottled with green spots and striae. 



Egg— Spindle shaped, laterally marked with raised vertical ridges, 

 between which are fine cross lines. 



Caterpillar— In its mature stage, it is relatively long, with the head 



small. 



Chrysalis— With the head relatively projecting; wing cases com- 

 pressed. 



Key to Species. 



1. Orange apex, surrounded by black; lower surface of hind wings com- 

 plete groen network, ^^^^• 

 No orange at apex of fore wings, 2- 



