12 



IXSECTS INJURIOUS TO STAPLE CROPS. 



parts. Much Paris green is wasted upon insects unable 

 to eat it and which it will, therefore, never kill. 



Insects may be roughly divided into two classes, those 

 which bite and those which suck their food. Among the 

 former are the beetles, grasshoppers, the larva3 of butter- 

 flies and moths, and the larvae of saw-flies; and among the 



Ibr. 



MX.pA 



Kldh^ 



Fig. 4. — Front-view Face of Grasshopper {Schiziocerca americnna). 

 ant., anUnma; oc, ocellus; ey., eye; cl., clypeus; Ibr., labrum, or 

 upper lip; mx.p., maxillary palpus; lab. p., labial palpus; gal., 

 galea, lobe of maxilla; lab., labium, or under lip. (Original.) 



latter are butterflies, flies, bees, and bugs, while the larvae 

 of most flies and bees do not possess mouth-parts homol- 

 ogous with those of the above. 



Biting Mouth-imrts. — Mouth-parts typical of those of 

 biting insects are easily seen in the grasshopper (Figs. 4, 5, 

 and 6). In brief, they consist of an upper and a lower 

 lip, between which are two pairs of jaws which work trans- 

 versely. The upper pair of jaws, or mandihies (md.), are 

 stout, short, and horny, usually sharpened at the tip, 



