98 BUTTERFLIES 



The Brimstone or Cloudless Sulphur 



Callidrayas euhule 



Practically all northern butterflies are variously marked 

 in different colors, while the butterflies of tropical regions 

 are commonly tinted in monotone, though often showing a 

 splendid iridescence. One with very little experience can 

 tell the look of a tropical butterfly and would be likely to 

 say at once that the Cloudless Sulphur is one of these. 

 The upper surface of the wings of the male is a clear plain 

 sulphur with merely the narrowest possible fringe of brown 

 around the margin made only by the colored marginal 

 scales. The under surface is lighter and sparsely dotted 

 in brown. In the females the marginal brown takes on the 

 shape of a series of small crescents and there is a single 

 round brown eye-spot just in front of the middle of each 

 front wing. 



While the Cloudless Sulphur is without doubt essentially 

 a tropical species it has an extraordinary geographical 

 range. It is extremely abundant in Mexico, Cuba, and the 

 tropical zone in South America. It extends south even to 

 northern Patagonia and north to New England, Wisconsin, 

 and Nebraska. 



Presumably in the tropics this species breeds continu- 

 ously, one generation following another in regular succes- 

 sion unless interrupted by drought or other natural 

 phenomena. In our Southern states there is more or less 

 Interruption by the winter season, so that it is commonly 

 considered to have only two broods, the butterflies hiber- 

 nating. Farther north there is probably only one brood in 

 summer, and perhaps not even that in the extreme limit 



