SB 

 818 

 C578 

 ENT 



No. 49, SECOND SERIES. 



lited States Department of Agriculture, 



DIVISION OF ENTOMOLOGY, 



L. O. HOWARD, Entomologist. 



THE SILVER FISH. 



{Lepistud saccliariiiu Linn.) 



By C. L. Marlatt, 

 First Assistcmt Entomologist. 



[Revised i-eprint from Bulletin No. t. New Series, Division of Entomology, U. S. Department of 



Agriculture, pp. 7(3-78.] 



This insect (fig. 1) is often one of the most troublesome enemies of 

 books, papers, card labels in museums, and starched clothing, and 

 occasionally of stored food substances. Its peculiar fish-like form and 

 scaly, glistening bod}-, together with its 

 very rapid movements and active efforts 

 at concealment whenever it is uncover- 

 ed, have attached considerable popular 

 interest to it and have resulted in its re- 

 ceiving a number of more or less descrip- 

 tive popular names, such as silver fish, 

 silver louse, silver witch, sugar fish, etc. 

 The species named above is the common 

 one in England, but also occurs in this 

 country, and, like most other domestic 

 insects, is now practically cosmopolitan. 

 It has a number of near allies, which 

 closely resemble it, both in appearance 

 and habits. One of these {Lepisma 

 [ Tliermobia] doniestica Pack) has cer- 

 tain peculiarities of habit which will be 

 referred to later. The peculiar appear- 

 ance of the common silver fish early 

 drew attention to it, and a fairly accu- 

 rate description of it, given in a little work jjublished in London in 

 1G05 by the Royal Society, is interesting enough to reproduce: 



It is a very small, silvery, shining worm or moth which I found nuich con- 

 versant among books and jiapers, and is supposed to be that which corrodes and 

 eats holes through the leaves and covers. It appears to the naked eye a small, 

 glittering, pearl-colored moth, which, upon the removing of books and papers 

 in the summer, is often observed very nimbly to scud and jiack away to some 

 lurking cranny where it may better protect itself from any api)earing dangers. 

 Its head appears big and blunt, and its body tapers from it toward the tail, 

 smaller and smaller, being shaped almost like a carret.^ 



^^^^^ 



Fk;. 1. 



Lepisma saccharina: adult- 

 enlarged (original.) 



Micrographia, R. Hooke, London, 166"). 



