EASTERN UNITED STATES 



113 



Fig. 27. 



p. Napi, form 



Oleracea; egg, 



X27. 



fifteen sharp longitudinal ridges with cross-lines between. 

 Length about .05 of an inch. 



The young larva is of a glassy white, thinly clothed 

 with fine short hairs. As with several other species, the 

 egg-shell from which it emerges forms the 

 first meal of the young larva. 



The mature larva is about 1.25 inches 

 long, of a pale green color, with a darker 

 dorsal line, the entire surface covered with 

 fine short whitish hairs. 



The chrysalis is of a greenish or whitish 

 color finely speckled with black, and shaped 

 much as the other species. 



The larva, when ready to pupate, leaves 

 the cabbages and seeks some protected place 

 on the under side of a board or a fence-rail, 

 where it spins its button and loop of silk and changes 

 to a pwpa. This habit is not confined to this species, 

 but is common to the rest of the genus occurring in the 

 eastern United States. 



13. PlERIS YlRGINIENSIS, Edw. 



This is a form occurring in West Virginia, like Ole- 



racea^ except that it has no yellow on the under side of 



the wings. It is single-brooded, producing no summer 



form, while farther north tlie aberrant form Virginien- 



sls is one of the spring forms of Oleracea, and the parent 



of Oleracea-cesiiva, a summer form. The preparatory 



stages are like those of the preceding species, it seeming 



to be a descendant of one of its forms, probably Ole- 



racea-cestiva. 



West Virginia. 



h ^ 10* 



