THE BEETLE 



71 



give light live on flowers, especially the goldenrod ; the lumi- 

 nous species are active at night. The light-giving organ lies 

 in the abdomen. The 

 larvae also are luminous 

 and are known as glow- 

 worms (Fig. 76). 



In several of the forego- 

 ing families of beetles the 

 adults live free, while the 

 larvae penetrate into wood. 

 In the family of bark- 

 borers or engraver-beetles 

 (Scolyt'idse^, however, the 

 adult also lives and feeds 



in the innermost layers of Fig. 76.^ a firefly, Photuris. a. larva; 

 1 -t T +1-,' +U ^' ^^u^*- '^^® lines to the left of figures 



bark. In this case tne represent actual lengths of animals. 



adult beetle also is a lover I'rom Packard. 



of contact and darkness. As they eat in lines, a pattern is 



formed which is characteristic for each species. Along these 

 hnes, 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 species. An 

 example is the destructive Pine-borer (Fig. 77), 

 which is common throughout the United States 



Fiu. 77. — Den- and Canada, 

 droctonus, an ^^^ ^^ ^j^^ ^^^^ injurious of all the families 



engraver bee- *' 



tie. Magnified of beetles is that of the weevils (Curcu"lion'- 

 "StandardNat- ^^'"^ ")■ Most of our weevils are small, and their 

 urai History." heads are drawn out into a long snout by 



' From skolypto, to mutilate. 



^ curcutio, St. grain-weevil. 



