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 hne 

 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 North- 

 eastern states. The adults may be seen from spring 

 until autumn. They lay eggs upon clover and other 

 plants. These eggs hatch into small green caterpil- 

 lars that feed upon the leaves and are protectively col- 

 ored so they are comparatively seldom seen. When 

 the food plant is disturbed they drop to the ground. 



