202 



NATURE-STUDY 



FIG. 63. A Beetle. 



and bark-boring beetles are injurious to trees. Carpet-beetles 

 destroy our carpets. Tiger-beetles are active and feed upon 

 other insects, and so does the little 

 polka dotted ladybug. The large, 

 black water-beetle also feeds on other 

 insects. The goldsmith's-beetle is a 

 handsome cousin of the June-beetle. 

 The fire-fly is also a beetle. 



Flies, Mosquitoes, and Crane-flies 

 form another order, the Diptera (Two- 

 winged). The name refers to the 

 fact that these insects have only one 

 pair of fully developed wings, the 

 hind pair having become rudimentary. 



The House-fly is typical. This insect lays its eggs on 

 decaying manure or ex- 

 posed meat, etc. Very 

 soon small, white, footless 

 larvae hatch out, which 

 are called maggots, and 

 feed upon the substance 

 in which they are hatched. 

 After about a week the 

 maggots shrink into bar- 

 rel-shaped pupae (corre- 

 sponding to the butterfly 

 chrysalis), from which 



e, ,1 , , FIG. 64. Head and Mouth-parts of a 



after another week the predacious Beetle, 



adult winged flies emerge. (Photomicrograph.) 



The fly has a rather large head, connected by a very flexible 

 neck to the hairy thorax. This is well marked off from the 



