18 ILLINOIS BIOLOGICAL MONOGRAPHS [250 



face is also covered with short fine setae. In all of the genera of the Coc- 

 cinellini the dorsal shield is large and covers the greater part of the dorsal 

 aspect. It is not so heavily chitinized as in Chilocorus and is divided 

 longitudinally into four plates. Two of these are adjacent on the dorso- 

 meson and each bears three or more large chalazae and many small 

 setae. The lateral plates are smaller than the mesal and bear a fringe of 

 large chalazae on their lateral and cephalic margins. In Microweisea and 

 Scymnus the dorsal shield is only indicated and very slightly chitinized. 

 It appears to extend over the larger part of the dorsum and bears several 

 large black setae. These are arranged in three transverse rows, a row on 

 the cephalic and caudal margins and another midway between them. In 

 Hyperaspis the dorsal shield is wanting and the tergum is only slightly 

 chitinized. It is traversed by three rows of prominent black setae arranged 

 as in Scymnus and Microweisea. There are in addition to these larger 

 setae, many smaller and inconspicuous ones. 



The pleural area in C. bividnerus is the more or less reduced area ven- 

 trad of the dorsal shield (Fig. 2, prpl). It extends ventrad to the sternal 

 area. There is a small group of setae cephalo-dorsad of the procoxacoila 

 in most of the genera studied. This is the only group of setae located on 

 the lateral aspect of the prothorax. 



The prosternum of Chilocorus is the rectangular area located between 

 the coxal fossae. There has been much controversy among morphologists 

 as to the number of sclerites in this area. It is not my purpose to discuss 

 this question, there are, however, a few landmarks of this region that must 

 be considered. In all of the species studied there is a small pit, the fur- 

 cina, (Fig. 3, fur) found near the meso-caudal boundary of each procoxa- 

 coria. There is a distinct ridge extending between these pits which prob- 

 ably serves as a place for the attachment of muscles. The prosternum of 

 Chilocorus, Epilachna, Microweisea and Hyperaspis usually bears a few 

 small setae and chalazae just cephalad of the procoxacoria, while in all of 

 the genera of the Coccinellini it bears two distinct verrucae which are 

 located adjacent to the meson. 



Mesothorax and Metathorax 



In general the mesothorax and metathorax of coccinellid larvae are so 

 nearly similar that a single description will suffice for both of them. Each 

 of these segments is wider than long, but in other respects they are similar 

 to the prothorax in form. 



The mesotergum in C. bivulnerus (Fig. 1, mst) is distinctly longer and 

 narrower than the metatergum (Fig. 1, mtt). In practically all of the 

 genera of the Coccinellini the mesotergum and metatergum are subequal 

 in length, but the metatergum is as a rule wider than the mesotergum. In 

 Microweisea, Scymnus, and Hyperaspis the mesotergum is longer and 



