4 Royal N. Chapman 



the purpose of gluing the egg to the leaf. The egg membranes remain 

 attached to the leaves thruout the season, and even in the fall may be 

 found adhering to the deserted blotch mines. 



The larva 



The larva varies so greatly, from the first instar to the last, that it is 

 at first difficult to recognize it as the same species in the different instars. 

 When the larva is first hatched (Plate I, 2), the prothorax, into which the 

 head is retracted, is very broad in proportion to the rather slender 

 abdomen, and the general appearance is like that of the buprestid larvae 

 which burrow in the wood (Burke, 1917). At each side of the head, a 

 small, clublike appendage projects from the prothorax. These append- 

 ages are enlarged at their distal ends and are covered with a very thin, 

 spinous layer of chitin. The larva is able to retract the appendages to 

 some extent, and seems to use them while feeding, as is described later. 



The size of the head, as determined by measuring to the outer margins 

 of the longitudinal apodemes (Plate I, 2), has been found to be uniform 

 within each instar. The head of the first instar measures 0.01 millimeter 

 and that of the second instar 0.14 millimeter. 



In addition to its larger size, the larva of the second instar (Plate I, 3) 

 differs from that of the first in the smaller proportionate size of the pro- 

 thorax, a difference which is due to the relatively smaller head which is less 

 completely retracted into the prothorax. Whereas the prothorax at the 

 beginning of the first instar is approximately twice the width of the remain- 

 ing segments of the body, which are all of about uniform width, the body 

 of the second-in star larva gradually tapers from the rather broad prothorax 

 to the terminal, or tenth, abdominal segment, which is the narrowest of 

 the series. A rectangular chitinous shield is developed on the median area 

 of both the dorsal and the ventral side of the prothorax. 



Even within each instar there is a noticeable difference with regard to 

 the retraction of the head. During the first part of each instar, the head 

 is larger in proportion to the remainder of the body, and is usually more 

 retractile: but later, after the body has grown, the head is proportionately 

 smaller and somewhat less retractile. 



The larva of the third instar (Plate I, 4) differs from the second mainly 

 in size, the head measurement being 0.217 millimeter. On the ventral side 

 of the ninth and tenth abdominal segments there appears a pair of rudi- 

 mentary prolegs, so closely associated with each other that they seem 

 almost as one. In the second instar these are so small that their presence 

 is detected with difficulty, while in the third instar they may be seen 

 distinctly with the aid of a lens, or even with the naked eye if the larva 

 is attempting to crawl about. 



Thus the three instars of this larva exhibit successive stages in the 

 modification of the whole body, especially in the head and the prothorax. 

 The first instar retains the typical condition of the buprestid larvae, with 

 the relatively large head retracted into the prothorax; while each of the 

 following instars exhibits a modification of the relative size of the head 

 and the prothorax, until, in the third instar, the mature larva seems to 

 have lost the characteristics of the wood-boring Buprestidae. 



