.16 



CALIFORNIA STATE COMMISSION OF HORTICULTURE. 



FIG. 12. Mouth parts of a cockroach (/*</* unjttcra pennsylvanica). A, labruin : 

 B, mandible; C, hypopharynx; D, maxilla; E, labium; c, cardo; g (of maxilla), 

 galea; g (of labium), glossa; I, lacinia; Ip, labial palpus; m, mentum; mp, max- 

 illary palpus; p, paraglossa ; pf, palpifer; pg, palpiger; s, stipes; sm, submen- 

 tum. B, D, and E are in ventral aspect. 



insects, distinguished from each other by their mouth parts, the one 

 having biting or gnawing organs, and known as mandibulate insects. 



Beetles, grasshoppers, locusts, etc., belong to 

 this class. In the other, the mouth parts are 

 fitted for sucking only, and the insects acquire 

 their nourishment by inserting their beaks 

 into plants or animals and absorbing the 

 juices by suction. These are known as haus- 

 tellate insects, and in this class we find many 

 of the greatest pests of the farmer and fruit- 

 grower, among them the plant lice, or aphids, 

 scale bugs, etc. In their perfect state, moths 

 and butterflies derive their nourishment by 

 suction, sipping the nectar from flowers with 

 the long, thread-like tube which forms the 

 mouth. Really, the haustellate mouth is a 

 form of the mandibulate, modified to suit the 

 habits of its possessor. 



In the biting insects (Mandibulates) the 

 mouth is composed of six different parts. 

 First, the mandibles, a pair of horny curved jaws, often serrated, or 

 supplied with sharp, saw-like teeth. Secondly, a second pair of jaws 

 located beneath the mandibles, and generally of four parts and arranged 



FIG. 13. Labium of Harpalus 

 caliginosus, ventral aspect. 

 g, united glossse, termed the 

 glossa; m, mentum ; p, palpus ; 

 pg, palpiger ; pr, paraglossa ; 

 sm, submentum. The median 

 portion of the labium beyond 

 the mentum is termed the 

 ligula. 



