ANATOMY OF INSECTS - - EXTERNAL 



used, and their structure is so constant and characteristic in different 

 groups as to furnish one of the best means of classification. Most 

 of the orders possess 

 one of the two main 

 types of mouth-parts, 

 those formed for 

 biting (mandibulate), 

 and those formed for 

 sucking (suctorial, or 

 haustellate). The bit- 

 ing type, as found in 

 the grasshopper, is the 

 more typical, and will 

 therefore be discussed 

 first. 



The labruin, or up- 

 per lip, is a simple 



flap projecting Over FIG. n. Mouth-parts of grasshopper, typical biting 

 the upper part of the or mandibulate mouth-parts 



Openin " Of the mOUth //'>-, labrum, or upper lip ; md, mandible ; mx, maxilla ; lab, 



labium, or lower lip ; /, palpus ; g, galea ; /, lacinia ; Kg, 



and covering the man- ligula . hyh hy popharynx 



dibles. It is hinged on 



the posterior margin, but otherwise is free and may be slightly 



protruded or retracted, to aid in bringing food to the mandibles. 



FIG. 12. Various forms of mandibles 



A, grasshopper (Melanoplns) ; B, tiger beetle (Cicindelidae) ; C, bee (Apis) ;"Z>, Onthopha- 

 gus ; E, lace-winged fly (Chiysopa) ; f-f, soldier termites. (After Hagen, from Folsom) 



The mandibles, or jaws, are composed of a single toothlike 

 piece and move in a transverse plane. The form of the mandibles 



