The Moths and Butterflies 445 



west being the favored regions of distribution. All the species except two or 

 three are of medium size, thai is, have an expanse of i^ to 2 inches, and 

 have white or yellow, from light sulphur to orange, as ground color, with 

 markings of black. The larva; are mostly green, longitudinally striped, 

 with more or less distinct lines usually paler, and harmonize so thoroughly 

 in coloration and ajipearance with the green foliage on which they feed that 

 they are not often seen. The chrysalids are naked, supported at the pos- 

 terior tip and also by a loose silken bridle, and distinguished from other 

 butterfly pupa; by a conspicuous median-pointed process on the head end. 

 The males of many Pierids give off a pleasing aromatic odor which comes 

 from certain scent-scales (androconia) scattered about over the wing-surface. 

 If the fore wings of a freshly caught male cabbage-butterflv be rubbed 

 between thumb and tmger, this scent can be readily smelled on the fingers. 

 It is used to attract or excite the females. 



The three most abundant whites in the eastern and northern states are 

 Pontia prolodice, P. napi, and P. rapa, the larvae of all three species being 

 voracious cabbage-eaters. P. rapa, the European cabbage-butterfly, is a 

 European butterfly which got to Quebec about i860 and since then has 

 spread over the whole country and is the most serious pest among all the 

 butterflies; it expands from i-j inches (male) to nearly 2 inches (female), 

 has faintly, yellowish-white wings with the base and apex of fore wings 

 blackish and w-ith two circular black dots on fore wings of the female and 

 one in the male; there is a single black spot (in male very faint) on front 

 margin of hind wings; under sides of hind wings and tip of fore wings lemon- 

 yellow. P. prolodice, the southern cabbage-butterfly, or checkered-white, 

 has at least three black spots besides a blackish apical border on the fore- 

 wings of the male, while both the wings of the female are much checkered 

 with blackish brown; the under side of the hind wings is white in the male. 

 P. napi, the northern cabbage-butterfly, or mustard-white, appears in eleven 

 or twelve appreciably different patterns, but characterized through all this 

 variety by the pale or distinct grayi.sh bordering of the veins; there is but 

 little blackish on the wings of the male, at most one or two circular spots 

 and a blackish apical border. In the western states the species of Pontia 

 which will be found by most collectors are beckeri, distinguished by green 

 markings on the under side of the hind wings; occidetitalis, much like pro- 

 lodice, and sisymhri, a small species with the veins of the hind wings widely 

 bordered with blackish brown on the under side. A beautiful Pierid is 

 the pine-white, Xeophasia mcnapia, of the Pacific states and Colorado; in 

 both male and female the black color above is limited to the fore wings; 

 there is a border along the costal margin from base to beyond the middle, 

 where it bends in along the outer margin of the discal cell as a swollen club- 

 like blotch; in addition the apex is broadly bordered with black in which 



