THE PIER1DS 



pillar feeds upon the outer leaves of the cabbage 

 and, therefore, is less obnoxious than that of 

 Pieris rapes, which bores holes into the cabbage 

 heads. It is triple-brooded, and spends the winter 

 as a chrysalis. The individuals which come from 

 these hibernating chrysalids are smaller than those 

 of later broods, as if they had literally been pinched 

 with the cold. These small butterflies were for 

 some time considered a distinct species. 



The checkered white is distributed over the 

 whole United States, though its natural home is 

 in the Mississippi Valley. It was once very 

 abundant ; but the introduction of the European 

 species has imposed upon the checkered white a 

 checkered career and it is now rarely taken. 



The Gray-veineu White 

 Pieris napi (Pi'e-ris na'pi) 



Plate XIV, Fig. 6-9 



In the most common form the wings are white above and 

 below, with a scarcely perceptible tinge of greenish yellow. 

 Sometimes there is a dark spot in cell M 3 of the fore wings, 

 but usually the wings are immaculate. The base of the wings, 

 however, and the basal half of the costal margin of the front 

 wings, are powdered more or less with dark scales, and the 

 veins of the wings, especially on the lower side, are grayish. 

 Expanse of wings one and seven-tenths inches to two inches. 



This species occurs throughout Canada and the more north- 



75 



