534 



AN INTRODUCTION TO ENTOMOLOGY 



Fig. 655. 



Other species are leaf-miners. Baliosus rubra is a good representative 

 of this group (Fig. 654). It varies in length from 3 mm. to 5 mm. 

 It is of a reddish color, with the elevated portions of 

 the elytra more or less spotted with black. The larva 

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

 the transformations 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 

 Fig. 654. Coleoptera are certain bright golden, green, or irides= 

 cent 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 con- 

 cealed beneath the prothorax; and the margins of the prothorax and 

 elytra are broadly expanded, forming an approximate- 

 ly circular or oval outline, and suggesting a resem- 

 blance to the shell of a tortoise (Fig. 655). Not all 

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

 that are, the brightness of the colors is said to de- 

 pend 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 larvae 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 back, and 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 larvae fasten the caudal 

 end of the body to the under side of a leaf; the skin then splits open, 

 and is forced back to this end of the body, where it remains. 



The one-dotted or five-dotted tortoise, Physondta unipunctdta. — 

 The largest of our bright-colored tortoise-beetles is common in mid- 

 summer, feeding on the leaves of wild sunflower. It measures from 

 9 to 12 mm, in length, and is yellow, with the margins whitish. 

 On the prothorax there are five black dots — two close together in 

 front, and three more widely separated behind. Sometimes all but 

 one of these dots are wanting. It was this form that was first de- 

 scribed, hence the name Mnipunctata. We have found the larvae abun- 

 dant in July on the same plant with the adults. 



The milkweed-tortoise, Chelymorpha casstdea, is a large, brick 

 red species, which measures from 9 mm. to 12 mm. in length, and has 

 the prothorax and wing-covers marked with many black spots. This 

 species feeds on milkweed {Asclepias) and various other plants. 



