THE LADY BEETLES. 



507 



small, and strongly emarginate in front; elytra convex, not truncate 

 at tip ; front coxae transverse, separate, the coxal cavities closed be- 

 hind, except in Coccidalaj middle coxa 1 rounded; hind coxae trans- 

 verse, widely separated; abdomen with five free ventral segments, 

 the dorsal portions of which are partially membranous; tarsi 3- 

 jointed. the second joint dilated and spongy beneath. 



Taking into consideration the foregoing characters. LeBaron has 

 well said that: "In a systematic point of view the Coecinellidae 

 occupy a remarkably anomalous and isolated position. Whilst hav- 

 ing the rounded form of the plant beetles, the clavate antenna? of 

 the scavengers, 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 earnfvora. 

 all of which have their bodies more or less elongated, their tarsi 5- 

 jointed. their antenna"' filiform, and their palpi slender or but mod- 

 erately dilated. ' ' 



The Coccinellida? are among the most beneficial of insects, being, 

 with very few exceptions, predaceous in both the larval and adult 

 stages. They seem to be especially adapted to keeping in check the 

 extensive families' of plant lice, both the leaf-lice ( aphids) and the 

 bark-lice (coccids) upon which they feed voraciously. It is not un- 

 common to find in an orchard branches of trees thickly covered with 

 the scales of bark-lice, almost every one of which has been torn open 

 and its occupant devoured by these lady-beetles. They are also 

 known to feed upon the eggs of many forms of larger insects, upon 

 chinch bugs and upon spores of the lower cryptogams and pollen 

 grains. After examining the stomach content of 39 specimens. Dr. 

 S. A. Forbes states that "the function of" th'e beetles of this family 

 of limiting the multiplication of plant-lice is expressed by the fact 

 that these insects compose a fourth of the food of this entire collec- 

 tion. The pollen of grasses and Composite make 14 per cent., the 

 spores of lichens four per cent., and those of fungi 45 per cent., or 

 nearly half the whole." Chinch bugs made up 10 per cent, of 

 the entire food eaten by members of the genus Hippodamia, taken 

 in a cornfield ivhere such bugs were abundant.* 



The larvae of the Coccinellida are oblong, blackish 

 grubs, and are usually beset with spines, which are in 

 turn armed with smaller spines or prickles, giving 

 them, when magnified, a formidable appearance. 

 (Fig. 183.^ In many cases the larva? are spotted or 

 banded in reds, black and yellows. They bear some- (After Forbes.) 



*"The Food Relations of the Carabidfe and Coccinellidse" in Bull. Xo. 6, 111. Lab. Xat. Hist., 1883. 



