STRUCTURE AND DEVELOPMENT OF INSECTS 



27 



Biting Mouth-parts. 

 insects are easily seen 

 in the grasshopper 

 (Figs. 17 and 18). In 

 brief, they consist of an 

 upper and a lower lip, 

 between which are two 

 pairs of jaws which 

 work transversely. The 

 upper pair of jaws, or 

 mandibles (md.} , are 

 stout, short, and horny, 

 usually sharpened at 

 the tip, slightly serrated 

 at the margins, and 

 flattened at the base. 

 The lower pair of jaws, 

 or maxillce (mx.}, are 

 longer, not so strong, 

 and to each of them is 



Mouth-parts typical of those of biting 



'A 



FIG. 17. Front-view face of grasshopper (Schizto- 

 cerca americana): ant., antenna; oc., ocellus; 

 ey., eye; cl., clypeus; Ibr., labrum, or upper 

 lip; mx.p., maxillary palpus; lab. p., labial pal- 

 pus; gal., galea, lobe of maxilla; lab., labium, or 

 under lip. 



attached an accessory lobe, and a jointed 

 B 



FIG. 18. A, mouth-parts 

 of grasshopper sep- 

 arated to show posi- 

 tion and relation; B, 

 mouth-parts dissect- 

 ed; Ibr., labrum; md., 

 mandible; hyp., hypopharynx or tongue; mx.p., 

 Jb. p., labial palpus; lab., labium; max., maxillae. 



maxillary palpus; 



