3 §4 THE STUDY OF INSECTS. 



northern portions of the United States. The larva feeds 

 on cabbage. 



The Checkered White, Pontia protodice (Pon'ti-a pro- 

 tod'i-ce). — The two sexes of this species differ greatly in 

 appearance, the female being much more darkly marked 

 than the male. The wings are white, marked above with 

 grayish brown. There is a bar of this color at the end of 

 the discal cell ; beyond this there is in the male a row of 

 three more or less distinct spots, and in the female an 

 almost continuous band of spots. Besides these there is in 

 the female a row of triangular spots on the outer margin of 

 both fore and hind wings, and on the hind wings a submar- 

 ginal zigzag bar. 



The larva of this species is colored with alternating 

 stripes of bright golden yellow and dark greenish purple, 

 upon which are numerous black spots. It feeds upon cab- 

 bage and other cruciferous plants, and occurs in nearly the 

 whole of the United States. Both this and the preceding 

 species seem to become greatly lessened in numbers by the 

 increase of the imported Pieris rapce. 



II. The Orange-tips. — These, like the butterflies compris- 

 ing the preceding group, are white, marked with black. 

 Their most characteristic feature is the presence on the 

 lower surface of the hind wings of a greenish network, or a 

 marbled green mottling. This usually shows through the 

 wing so as to appear as a dark shade when the wings are 

 seen from above (Fig. 463). Many species have a con- 

 spicuous orange spot on the api- 

 cal portion of the front wings. 

 This has suggested the common 

 name Orange-tips for the group. 

 But it should be remembered 

 that some species lack this 

 mark, and that in some others it 

 is confined to the males. Nearly 

 all of our species are confined to 

 the far West. The two following occur in the East. 



Fig. 463. — Synchloe olympi 



