SOME TROUBLESOME INVADERS 377 



When this tail-like organ is suddenly straightened by 

 the insect, its body is thrown into the air and projected 

 some distance forward. The action and situation of this 

 spring-like organ have given these queer insects the name 

 of spring-tails. 



Injuries of the spring-tails. The following letter ac- 

 companied with specimens from a correspondent sets 

 forth in a clear way one form of annoyance occasionally 

 caused by these insects. "We keep our milk in a cave 

 dug into the sand and rocked up on the sides but not 

 'pointed up.' It is covered with rough boards sup- 

 ported by pine poles in which borers are working. The 

 cave was dug last fall. The floor is well-drained coarse 

 sand. We cover the milk to prevent the insects in the 

 sample bottle getting in, but to no purpose. We have 

 used two thicknesses of cloth held down by tight cord 

 and heavy cover on top. We have also used paper 

 similarly fastened, but to no profit. The insects get in, 

 in spite of everything. Through a small glass they appear 

 like maggots, but often individuals will jump a couple 

 of inches like fleas. They are not in the cow, for milk 

 set in the house does not show them, but of course we 

 cannot keep milk in the house these days. What are 

 they, how do they get in the milk, and how can we keep 

 them out ?" Although the specimens were badly broken 

 down, we were able to identify them as spring-tails, but 

 could not determine the species. It is altogether likely 

 that the dampness of the milk cellar attracted them, 

 and it is quite possible that they fed upon the cream in 

 the milk receptacles. It is believed that spring-tails 

 live largely, if not wholly, upon decaying vegetable 

 matter. 



