24 IN SECT A. 



which bears the antennae.^ When the labrum is 

 raised, the two hard, dark mandibles (Fig. 3, md; 

 PL I., Fig. 10) are exposed. These have cutting 

 edges, which prove that the locust bites its food. 

 They move sideways, as do the jaws of most Arthro- 

 pods.^ When one mandible is cut away, the mouth 

 (Fig. 14, ;;/, p. 36) is seen. 



The mouth parts of locusts are strong and well fit- 

 ted to masticate the tough fibres of vegetable tissues. 

 The destruction of crops caused by the Rocky Moun- 

 tain locust, Calopieiuis spretus, is a familiar fact. 

 One of our common species of locusts, Caloptenus 

 atlanis, has been known to migrate and to extend its 

 ravages over New England. In 1749 and 1754 ''no 

 vegetables escaped these greedy troops ; they even 

 devoured the potato-tops." Days of fasting and prayer 

 were appointed by the colonists to avert the dread 

 calamity.^ 



Behind the mandibles is the first pair of maxillae 

 (PI. I., Fig. 3, mx' ; Fig. 11, p. to). 



Each maxilla consists of the cardo (Fig. 11, cd), stipes, 

 (//), lacinia (/^), the spoon-shaped galea {gl), and the 

 five-jointed maxillary palpus (^ ) . 



Between the bases of this pair of maxill?e on the 

 median line is the tongue (PL I., Fig. 3, tn), a stout, 

 reddish organ with a chitinous upper surface rough- 

 ened by papillse. 



1 Third A'efiort U. S. En/o»iological Commission, p. 279. 



^ An exception to this rule is found in Balaninus (weevil), in 

 which the jaws move vertically (see p. 165). 



^ S. H. Scudder in U. S. Geological Sw'7<ey of A'ebraska. 

 Final Report, 1872, pp. 249-261. 



