206 NEBRASKA STATE HORTICULTURAL SOCIETY. 



turtle, whence the popular name. Many have the singular power, in 

 a greater or less degree, of changing their color when alive, and as we 

 shall show further on, some of them shine at will with the most brill- 

 iant metallic tints." 



In speaking of the larval habits of these beetles, the writers of the 

 article from which I have quoted dwell at length upon a peculiar 

 habit common to all of these tortoise beetles, as well as to a number 

 of allied forms, viz., the use of their excreta as a sort of shield or 

 protection against predaceous insect enemies and parasites. 



"The larvae of all the species that have been observed are broad 

 and flattened like the beetles, and have the margins of the body fur- 

 nished with spines which are often barbed (see Figs. 19, b ; 21, a). 

 Usually there are thirty-two of these spines, or sixteen on each side 

 of the body. Four of these are situated on the prothorax, which 

 forms two anterior projections beyond the common margins ; four of 

 them — the two anterior ones longer than the others — are on each of 

 the two following thoracic segments, and each of the abdominal seg- 

 ments is furnished with but two. There are nine elevated spiracles 

 each side superiorly, namely, one immediately behind the prothorax 

 and eight on the abdominal segments. The fore part of the body is 

 projected shield-like over the head, which is retractile and small. 

 Almost all of the larvae of the beetles belonging to the great Chryso- 

 mela family, of which the Colorado potato bug may serve as an ex- 

 ample, have, besides the six legs at the anterior end of the body, an 

 additional proleg, or protuberance which serves as such, at the poste- 

 rior end ; but the larvae of our tortoise beetles have no such proleg, 

 and the six anterior legs are short, thick, and fleshy, and, with the re- 

 tractile head, give these larvae, from a side view, as great a resem- 

 blance to a turtle as have the beetles. 



" Though lacking an anal proleg, however, they are characterized 

 by having a movable forked tail, in the shape of two long, prong-like, 

 horny filaments, which both spring from a broad neck situated im- 

 mediately above the anus. This latter projects and curves over the 

 back at the will of the insect, and by the aid of this fork and of some 

 of the lateral spines, it forms the parasol of dung which so nicely 

 protects it. * * * 



"All the tortoise beetle larvae which we have bred, have come to 

 their growth in about three weeks after hatching. They cast their 



