CHAPTER X 



FIG. 270. 



INTERRELATIONS OF INSECTS 



Insects in general are adapted to utilize all kinds of organic 

 matter as food, and they show all gradations of habit from 

 herbivorous to carnivorous. The many forms that derive 

 their food from the bodies of other insects may conveniently 

 be classed as predaceous or parasitic. 



Predaceous Insects. Among Orthoptera, Mantidae are 

 notably predatory, their front legs (Fig. 62, C) being well 

 fitted for grasping and killing other insects. The predaceous 

 odonate nymphs have a peculiar 

 hinged extensible labium with 

 which to gather in the prey. The 

 adults catch with surpassing 

 speed and precision a great va- 

 riety of flying insects, mostly 

 small forms, but occasionally but- 

 terflies of considerable size. The 

 eyes of a dragon fly are remark- 

 ably large; the legs form a spiny 

 basket, probably to catch the prey, 

 which is instantly stripped and 

 devoured, these operations being 

 facilitated by the excessive mobil- 

 ity of the head. The hemipter- 

 ous families Corixidse, Notonect- 

 idse (Fig. 224), Nepidse, Belos- 



tomidse (Fig. 22), Naucoridse (Fig. 62, D), Reduviidse and 

 Phymatidse are predaceous, with raptorial front legs and sharp 

 beaks. Some of the Pentatomidse (Fig. 270) are of con- 

 siderable economic value on account of their predaceous 

 habits. Most of the Neuroptera feed upon other insects. 



307 



Nymph of Podisus spinosus suck- 

 ing the blood from a clover cater- 

 pillar, Colias philodice. Natural 

 size. 



