356 



NATURAL HISTORY OF ARTHROPODS. 



anatomist, over two hundred years ago, and has since been described by several 

 naturalists. The rapping is caused by a forcible hammering of the hard wood with the 

 head of the beetle, and it is noticeable that the beetle selects places where the wood 

 will act as a sounding-board for its curious sonifaction. 



The larva of Anobium is cylindrical, short, often slightly dilated toward the 

 posterior extremity, and has six legs ; it has no ocelli, short antennae, a labrum which 

 reaches nearly to the extremity of the short, stout mandibles ; its anal opening is 

 longitudinal. The larvae sometimes develop in one year, and sometimes require 

 longer. Both beetles and larva? often do much damage to furniture, books, drugs, 

 and provisions. Linnaeus found that A. pertinax destroyed his chairs ; Kirby and 

 Spence complain that A. striatnm has the same habit, and also injures picture-frames 

 and the boards of floors. Both of these species of Anobium attack books, not only 

 for the leather with which they are bound, but also for the paste used in their binding. 

 Spence mentions wholesale destruction of oaken beams used to support floors in the 

 old mode of building houses in Belgium, necessitating renewal of these beams at great 

 expense. 



Sitodrepa panicea, a cosmopolitan species often mentioned under the name of 

 Anobium paniceum, differs from Anobium by not having the metasternum excavated 

 in front. It is a brown beetle densely covered with light brown pubescence, and 

 about 0.1:2 of an inch long. The earlier stages of this beetle were described in 1721 

 by Frisch, who found the larvae devouring the inside of a piece of rye-bread. Later 

 the same author writes that this insect injures books, and attacks many kinds of dead 

 animal matter. Prof. A. S. Packard mentions finding this species in wasps' nests 

 preserved in museums, where it probably ate the dried wasps left in the nests. Dr. 

 H. Shinier has raised this species from larvae feeding in red beads " made of some 

 kind of colored paste." 



The genus Ptinus, of which P. far is a widely diffused representative, differs from 

 Anobium both in form and in having the long filiform antennae 

 inserted closely together upon the front. Ptinus fur is of an 

 uniform brown color, and is pubescent ; it is only about 0.1 of 

 an inch long. De Geer described and figured the preparatory 

 stages of this species in 1774. This species is known as a 

 museum pest, attacking insects and other animals preserved in 

 collections. I have found it swarming in barrels of wool which 

 had been clipped off the fleece and thrown aside because it was 

 full of sheeps' dung and other dirt. According to E. Perris 

 the female of P. dubius, a French species, oviposits in the male 

 blossoms of Pimis maritima. The larva grows rapidly, feeding 

 upon the pollen of the pine, and forms its cocoon of pollen-grains cemented together 

 by a mucilaginous secretion. P. brunneus, a species found in 

 Europe and in the United States, sometimes attacks the binding 

 of books. 



The diversity of habits of the larvae of Ptinidae can be easily 

 seen by the above selections from what is known of their life 

 history. They are generally easily destroyed by subjecting the 

 materials in which they feed to heat, or to the action of benzine vapor in a closed tin 

 box. A convenient way of destroying these and other insects in books, in such drugs 

 as are not injured by subjecting them to a dry heat of 100 C, in clothing, and in 



FIG. 399. Ptinus fur. 



FIG. 400. Larva of 

 Ptinus fur. 



