239] THE LAR VA E OF THE COCCI NELLI DA E—GA GE 



INTRODUCTION 



The adults of this family are known to most persons as lady-bugs or 

 ladybirds. Their distinctive characteristics are the apparently three- 

 segmented tarsi and the broad hatchet-shaped distal segment of the 

 maxillary palpi. Other characteristics are: the eleven segmented anten- 

 nae, in which the distal segments are commonly modified to form a more 

 or less distinct club-shaped enlargement; the insertion of the antennae 

 near the mesal margin of the compound eyes; the ventral direction of the 

 mouth; the retraction of the head into the small transverse prothorax; 

 the transverse front coxae; the closed coxal cavities, except in Coccidula; 

 the convex elytra; and the abdomen consisting of five to seven exposed 

 ventral segments. 



Le Baron has said, in speaking of this family, that "The Coccinellidae 

 occupy a remarkably anomalous and isolated position. Whilst having 

 the rounded form of the plant beetles, the clavate antennae of the scavan- 

 gers, and the dilated palpi of the fungus beetles, they agree in food and 

 habits with none of these, but resemble in their predaceous habits the 

 ground beetles and the soft-winged carnivora, all of which have their 

 bodies more or less elongated, their tarsi five-jointed, their antennae fili- 

 form, and their palpi slender or moderately dilated." 



The larvae of the Coccinellidae, though they may be known to many 

 people, are not as a rule associated with the adult coccinellids or lady-bugs. 

 The most distinctive characteristics of these larvae are: their porcupine- 

 like appearance; elongated body which is usually striped or mottled with 

 red, black, white or yellow areas; small three-segmented antennae; power- 

 ful mandibles; and the habit of being continually on the move. From the 

 systematist's point of view these larvae do not show any unusual charac- 

 teristics such as Le Baron has noted for the adults, for they resemble in 

 most respects the distinctly predaceous types of coleopterous larvae. 

 This is true even of the Epilachninae, which are phytophagous. With 

 the exception of this subfamily the Coccinellidae are all more or less pre- 

 daceous in their adult stages, and almost entirely so in their larval stages. 



The purpose of this investigation is to study the morphology of coc- 

 cinellid larvae and to arrange tables for the identification and classification 

 of a few of the more common species. The work has been limited to those 

 genera and species which have in the main been found in or reported from 

 Illinois. Specimens were collected and bred during the autumn of 1918, 

 and others were obtained from the collections of Dr. A. D. MacGillivray, 

 the University of Illinois, the Illinois State Natural History Survey, and 

 a specimen of Brachyacantha ursina received from Cornell University. 



