THE TRIBE OF THE YELLOWS 101 



more tinged with orange. The female is strikingly dif- 

 ferent, the wings being plain pale yellowish buff marked 

 only with a round blackish eye-spot near the middle of 

 each front wing and the barest suggestion of a dark line 

 around the extreme margin. 



The Clouded Sulphur 



Eurymus philodice 



It is an interesting fact that the butterfly which one is 

 most likely to find in fields and along roadsides during 

 practically all the weeks of summer has seldom if ever been 

 noted as a destructive insect. The Clouded Sulphur 

 is probably the commonest species in its group. There 

 may be times when the White Cabbage butterfly or other 

 forms are more abundant, but the Clouded Sulphur re- 

 tains its place season after season, with comparatively 

 little noticeable variation in its numbers. This is doubt- 

 less an illustration of an insect which has established such 

 relations with its food plants and its various insect and 

 other enemies that it remains in a fairly stable equih- 

 brium — an example of what is often called the balance of 

 nature. 



The Clouded Sulphur is about the only medium-sized 

 yellow butterfly generally found in the Northeastern 

 states. It will easily be recognized from the accompany- 

 ing pictures, opposite pages 112, 113. The adults may be 

 seen from spring until autumn. They lay eggs upon clover 

 and other plants. These eggs hatch into small green 

 caterpillars that feed upon the leaves and are protectively 

 colored so they are comparatively seldom seen. When 



