INSECTS 



below the mouth. Behind the mandibles is a pair of 

 maxillae B, Mx) of more complicated form, fitted rather 

 for holding the food than for crushing it. Following the 

 maxillae is a large under lip, or labium (Lb), having the 



\ Ant 



Ht - Mai An W 



SoeGnff 



Fig. 67. Lengthwise section of a grasshopper, showing the general location 

 of the principal internal organs, except the respiratory tracheal system and 



the organs of reproduction 

 An, anus; Ant, antenna; Br, brain; Cr, crop; Ht, heart; hit, intestine; Mai, 

 rhian tubules; Mth, mouth; Oe, oesophagus; SoeGng, suboesophagea! 

 ganglion; Vent, stomach wentricu! . entral nerve cord; W y wings 



structure of two maxillae united bv their inner margins. 

 A broad flap hangs downward before the mouth to form 

 an upper lip, or labrum (Lm). Between the mouth ap- 

 pendages and attached to the front of the labium there is a 

 large median lobe of the lower head wall behind the mouth, 

 known as the hvpophar\tix (Hp 1 



Insects feed, some on solid foods, others on liquids, and 

 their mouth parts are modified accordingly. So it comes 

 about that, according to their feeding habits, insects may 

 be separated into two groups, which, like the iox and the 

 stork, could not teed either at the table of the other. Those 

 insects, such as the grasshoppers, the crickets, the beetles, 

 and the caterpillars, that bite off pieces of food tissue and 

 chew them, have the mandibles and the other mouth 

 parts of the type described above. Insects that partake 

 only of liquids, as do the plant lice, the cicadas, the moths, 

 the butterflies, the mosquitoes and other flies, have the 



[108] 



