56 



AN ECONOMIC ENTOMOLOGY. 



Fig. 28. 



house-keepers as the "fish-moth," or "silver fish." It is one 

 of the few species that prefers a dry, warm locality, and is found 



in cupboards and closets, hiding in 

 crevices, and running rapidly when 

 disturbed. It is about one-quarter 

 of an inch in length, oblong, a little 

 pointed towards both ends, and has 

 the body covered with minute, sil- 

 very-white, gHstening scales. It is 

 one of the largest species belonging 

 to the order, feeding upon starchy 

 substances and food remnants. It 

 sometimes becomes troublesome in 

 libraries, gnawing the calendered 

 surface of leaves and bindings and 

 defacing them. The insect can 

 scarcely be said to be injurious, but 

 it is often annoying, and may be 

 driven out by a free use of pyre- 

 thrum dusted in corners and crev- 

 ices. 



A much more common type is the 

 "spring-tail," so named from the 

 fact that the anal appendages consist 

 of two short, bristle-like processes, 

 arranged to enable the insect to leap 

 or spring. They are normally bent 

 under the body, held in place by a 

 catch-like organ until the insect de- 

 sires to move suddenly, when the 

 catch or spring is released, sending 

 the insect forward a surprisingly long 

 distance. When excited it progresses by a series of rapid leaps 

 of this kind, its course being decidedly erratic because no two of 

 the springs are made in the same direction. 



"Spring-tails," or Podurids, are found in moist locaHties, 

 wherever decaying vegetable matter occurs. In manure beds 

 they often occur in millions, and on warm days may come to the 

 surface in astounding numbers. I have seen a forcing bed cov- 



Bristle-tail or fish-moth ; Lepisma sp. 



