SOLDIER-BEETLES. 



63 



With a more or less retracted head. The prothorax is expanded 

 in a thin projecting margin, which in some cases almost entirely 

 covers the head. The peculiar power of emitting light serves 

 two useful purposes : it is no doubt a great protection to the 

 beetles, and it brings together the sexes. As a protection it 

 only fails in the case of bull-frogs, which gobble up such insects 

 in spite of the fire, which is, however, of a cold nature. In fact 

 such frogs can be readily attracted and caught by using fire- 

 flies as a bait. The larvas of fire-flies burrow in the earth, and 

 some of them are slightly luminous ; they feed upon the soft 

 bodies of other insects, upon snails, and upon other similar food. 

 A number of such insects are illustrated in Fig. 69. 



Other members of this family of beetles, which are diurnal 

 in their habits, are called "Soldier-beetles" (Fig. 70). They are 



Fig. 70.— Soldier-Beetles. — After Brehtn. 



also soft, and frequently quite gayly colored. They are found 

 upon flowers, where they feed upon pollen or nectar, being en- 

 abled to do so by the possession of a fleshy filament attached to 

 each maxilla. Botli fire-flies and soldier-beetles eat insects, some- 

 times even very large ones. The writer has in his possession a 

 common Lightning Bug, (Photinns pyralis Linn.), which was 

 found in the act of eating a beetle of equal bulk. But the bene- 



