— Ú¿ — 



after another and stinging them soon has laid out a dozen or 

 more victims. After the assault has been made the wasp 

 leisurely selects one from among them and marches off with it 

 to some suitable place where it is buried as described above. 

 Like some animals of prey this digger-wasp often apparently 

 destroys locusts simply as a pastime or maybe for practice. 

 The name of this wasp, according, to Conil, and others, is 

 Enodia fervois. 



It belongs to a rather large and well represented family of 

 solitary digger-wasps which naturalists call Sphcgidic. AVhile 

 this particular species of wasp seems to be partial to locusts as 

 a diet for its young, it is by no means the only representative of 

 the family here in Argentina that attacks locusts for this 

 purpose. At least a half dozen others are likewise enemies of 

 the dreadful pest. 



In addition to what these SpJiegidiC do towards killing off 

 the pest, there are also representatives of at least two other 

 families of solitary wasps which likewise supply their young 

 with locusts for their nourishment. These are the Larridic and 

 Pouipilida'. 



While all of these wasps, even when working together, can do 

 comparatively little towards keeping the locust-plague in check, 

 they help to do so, and it is but proper that we should recognize 

 in them friends worthy of our sympathy and protection. 



Digger-wasps '' by means of their powerful jaws and spinous 

 legs burrow with great rapidity in the ground, Avhere they form 

 a sort of nest ; provision it with some kind of prey which they 

 have stung and paralized; layan &gg thereunder, and cover 

 up the hole — the larva when it hatches feeding upon the food 

 thus provided by the parent ". 



Vertebrate Enemies. 



Birds. 



Birds stand at the head of the vertebrate enemies of locusts. 

 In fact they are so persistent in their search for and destruction 

 of insects that they have rightfully been called the "balancers" 

 in nature. In a wild state, and where not interfered with by 



