WEALTH OF INSECT LIFE 



173 



chief end of this insect is to feed the snakes which lie 

 in wait for him. It is a " snake-feeder " in the boy's 

 parlance. Children generally are wont to fear this 

 insect; they call it the " devil's darning-needle." They 

 have been told -- and they believe it --that the long 

 tail-like abdomen is a needle with which 

 the insect sews up children's ears. 



Entirely at variance with these strange 

 tales, the insect is not only harmless but 

 highly beneficial, since one of its chief 

 sources of food is the mosquito, with 

 whose piercing propensities all are fa- 

 miliar. When the day is clear and still 

 and the vertical rays of the sun make one 

 content to rest a while in the shade of 

 some spreading elm near the pond lily's 

 home, or down by some sluggish stream, 

 then it is, and there, that the dragon-flies 

 are most active, skimming along over 

 the water, darting up, then down, right 

 about face, all so quickly that at times 

 the eye can scarcely follow. Suddenly that rests its wings 

 one of them may halt to rest upon a stick a lon g ltsback ' The 



*' dragon-fly rests its 



or stump rising above the surface of the wings at right an- 

 gles with its body. 



water, or a dead limb overhanging, to 

 rest, probably, but more likely to train the eyes on the 

 surrounding space in quest of passing mosquitoes or 

 buzzing flies to be swooped down upon. Thus these 

 dragon-flies are sometimes called " mosquito-hawks." 

 Not unlike the raptorial birds, dragon-flies appear to 

 have a certain stick or stump as lookout for prey. If 



FIG, 137. A dam- 

 sel-fly, a Libellulid 



