TEE BUGS, OR SUCKING INSECTS. 101 



their manner of taking their food. It is formed of the 

 long, slender needle-like mandibles and maxillae which are 

 united so as to form a hollow sucking-tube. The tube thus 

 formed is ensheathed by the underlip {laiium) which is 

 long, hollow, and composed of four joints. Aboye, the 

 sucking-tube is protected by the labrum (Figs. 107 and 

 108, lir). There are estimated to be nearly 5000 species of 

 bugs in North America, but all have a beak ; and through 

 their different kinds of food and habits there is a chance 

 for the individuals of each species to get a living. 

 The bugs also differ from other insects, and somewhat 



Fia. 108. — Longitudinal section of a bug's head. Ibr, labrum; 26, labiiun; md, 

 mandible; mx, maxilla; sg, salivary gland (the arrows pointing outward show 

 the course of the salivary duct into the mouth; the inward-pointing arrows 

 indicate the throat and the direction taken by the food to the stomach); Itx, 

 muscles vrhlch elevate the roof of the mouth. 



anticipate the beetles, in the fore-wings, which are thick- 

 ened at the base so as to protect the thin under pair. Since 

 the basal half of the fore-wings is thus thickened, the 

 bugs are called Hemiptera, from hemi, half ; and pteron, 

 wing. 



Like the grasshopper, the bugs have an incomplete meta- 

 morphosis. Fig. 109 represents the transformations of the 

 chinch-bug, the young having no wings. After reaching the 

 stage e, the wing appears as in the stages / and g. This 

 bug does immense harm to farmers by sucking the sap of 

 wheat and corn. 



