COLEOPTERA 167 



The wedge-shaped leaf-beetles. — These insects are characterized by the 

 peculiar form of the body, which is narrow in front and broad behind. 

 In most of the species the body is much roughened by deep pits, and 

 usually the pits on the wing-covers are in regular rows. These insects 

 and the tortoise-beetles differ from other leaf-beetles in having the fore 

 part of the head prominent, so that the mouth is con- 

 fined to the under surface. Some of the larvae feed ex- 

 ternally upon the leaves and bear a parasol composed 

 of their excrement; other species are leaf -miners. 

 Baliosus rubra is a good representative of this group (Fig. 

 296). It varies in length from £ to £ of an inch. It 

 is of a reddish color, with the elevated portions of 

 the elytra more or less spotted with black. The FlG - 2 <> 6 - 



larva mines in the leaves of apple, forming a blotch-mine; the transforma- 

 tions are undergone within the mine. We have also found this species 

 mining the leaves of basswood in great numbers. 



The tortoise-beetles. — Among the more beautiful Coleoptera are cer- 

 tain bright golden, green, or iridescent beetles found on the leaves of 

 sweet potato, morning-glory, nettle, and other plants. In these beetles 

 the body is flattened below and convex above; the head is nearly or 

 quite concealed beneath the prothorax; and the margins of the pro tho- 

 rax and elytra are broadly expanded, forming an approx- 

 imately circular or oval outline, and suggesting a 

 resemblance to the shell of a tortoise (Fig. 297). Not all 

 of the species are iridescent ; and in the case of those that 

 are, the brightness of the colors is said to depend on the 

 emotions of the insect. What a beautiful way to express 

 one's feelings — to be able to glow like melted gold when 

 one is happy! Unfortunately for the beauty of our collections, these bright 

 colors disappear after the death of the insect. 



The larva? of the tortoise-beetles are flattened, and have the margin 

 of the body fringed with spines. At the caudal end of the body there is a 

 forked appendage which serves a very strange purpose. This fork is 

 bent forward over the backhand to it are attached the cast-off skins of 

 the larva and its excrement; these constitute a parasol. When about to 

 change to the pupa state these larva? fasten the caudal end of the body 

 to the underside of a leaf; the skin then splits open, and is forced back 

 to this end of the body, where it remains. 



The black-legged tortoise-beetle, Cassida nigripes, is a beautiful 

 golden species which lives on the vines of the sweet potato. It is a little 

 over j of an inch in length and each wing-cover bears three black spots 

 arranged in a triangle. The beetle loses its brilliant tone if disturbed 

 and when it dies the golden color fades to a yellowish-brown. 



Family Mylabrid^e 



The Pea-weevil Family 



These are small beetles, the larva? of which live in the seeds of legu- 

 minous plants. The head of the adult is prolonged into a broad beak; 

 and the wing-covers are rather short, so that the tip of the abdomen is 



