THE BEETLE AND ITS ALLIES 



53 



trees, but these are mostly carnivorous and are seeking 

 their prey there. The minute bark-borers or engraver 

 beetles (Scolytidse 1 ), however, feed on the innermost layer 

 of bark. As they eat in lines, a pattern is formed which 

 is characteristic for each species. Along these lines, niches 

 are made in which eggs are laid and larvae hatch. The 

 borings are injurious to the trees, often causing their 

 death. Herbaceous plants also are infested by certain spe- 

 cies. An example is the destructive Pine Borer (Fig. 55), 

 which is common throughout the United 



States and Canada. 



One of the most injurious 



of all the families of beetles 



is that of the weevils (Cur- 



culionidse 2 ). These beetles 



are small, and their heads 



are drawn out into a long 



snout by which they bore 



holes in plant tissue to 



receive their eggs (Fig. 



56). The dull colors of 



the beetles render them in- 

 conspicuous to insect-feeding birds. The number of species 

 is reckoned at over ten thousand, and the family is of world- 

 wide distribution, its dispersion having been aided by com- 

 merce. Grain-weevils are great pests in stored wheat, rice, 

 or maize. They also oviposit in the planted seeds. Buds 

 are attacked, and nuts, stone fruit, and fleshy fruits are 

 made " wormy " by them. 



Extremely destructive also is the great family of long- 



FIG. 55. Den- 

 droctonus, an 

 engraver bee- 

 tle. Magnified 

 2.5 times. From 

 "Standard Nat- 

 ural History." 



FIG. 56. Balani- 

 nus, a weevil, of 

 brown color. 

 From Packard. 



1 From (r/coXi57rTw, to mutilate. 



2 curculio, a grain-weevil. 



