1 66 ENTOMOLOGY 



brown with black markings, instead of being, as usual, yellow with black 

 markings. In the South, some males of the spring brood of Cyaniris 

 pseudargiolus are partly or wholly brown instead of blue. A melanic 

 male of Colias philodice occurs as an extremely rare mutation. 



Seasonal Coloration. When butterflies have more than one brood 

 in a year, the broods usually differ in aspect, sometimes so much that their 

 specific identity is revealed only by rearing one brood from another. 

 The same species may exist under two or more distinct forms during the 

 same season in other words, may be seasonally dimorphic, trimorphic 

 or polymorphic. 



Thus Polygonia interrogationis has two forms, fabricii and umbrosa, 

 which differ not only in coloration, but even in the form of the wings and 

 the genitalia. In New England fabricii hibernates and produces um- 

 brosa, as a rule, while umbrosa usually yields fabricii. 



FIG. 232. Cyaniris pseudargiolus; A, form lucia; B, molacea; C, pseudargiolus proper. 



Natural size. 



The little blue butterfly, Cyaniris pseudargiolus (Fig. 232), is poly- 

 morphic, to a remarkable degree. In the high latitudes of Canada a 

 single brood (lucia) occurs. About Boston the same spring brood ap- 

 pears, but under two forms: an earlier variety (lucia), which is small, 

 with large black markings beneath; and a later variety (molacea), which 

 is typically larger, with smaller black spots, though it varies into the form 

 lucia. Finally, in summer, a third form (pseudargiolus proper) appears, 

 as the product of lucia or else the joint product of lucia and molacea, and 

 this is still larger, but the black spots are now faint. In the warm South 

 the spring form is molacea, but while some of the males are blue, others are 

 melanic, as just mentioned a dimorphic condition which does not occur 

 in the North. Violacea then produces pseudargiolus, in which, however, 

 all the males are blue. 



Iphiclides ajax (Fig. 233) is another polymorphic butterfly whose 

 life history is complex. The three principal varieties of this species, 

 known respectively as marcellus, telamonides and ajax, differ not only in 



