DESCRIPTION AND CLASSIFICATION OF INSECTS. 'M 



the breathing organs may be observed near the lateral margin of 

 each segment. 



45. The legs consist of five parts, the first joint, coxa or hip, 

 the second or trochanter, the third, the femur or thigh, the 

 fourth, the tibia or shank, and the fifth, the tarsus or foot. The 

 tarsus is composed of three, four or five joints, and terminates 

 generally in two-hooked claws. The tarsus is sometimes made 

 the basis of the sections into which the order coleoptera is 

 divided. 



46. This order of insects is one in which the agriculturist is 

 particularly interested. It contains the tribe Rhincophera, 

 (snout beetles,) which is so numerous in species that not less 

 than 8,000 different insects belonging to it have been described 

 by one entomologist (Schoenherr.) It includes the insatiable 

 evils which are justly distinguished and dreaded for their attacks 

 upon grain and seeds. Immense quantities of Indian corn and 

 wheat in the crib or granary are destroyed every year in the 

 United States by the grain weevils, calandra granaria and calan- 

 (Ira remotepunctata. 



Order II. 



Orthoptera. (Orthos, straight ; ptera, wings.) 



47. This order includes crickets, grasshoppers, locusts, ear- 

 wigs, cockchafers, the mantis tribe. Most of these insects are 

 eminently destructive to vegetation. Upper wings of the con- 

 sistency of parchment ; mouth with mandibles and maxillae. 



Order III. 



Neuroptera. {Neuron, a nerve ; ptera, wings.) 



48. Dragon flies, May flies. Termites ; wings membranous, 

 naked and reticulated ; masticators. 



