LOCUST 421 



as the femur. The last division of the leg is the tarsus, which is made 

 up of three segments, each movable with the other. The segments 

 bear a series of pads, which terminate on the last one in a large 

 suckerlike disc known as the pulvillus. 



There are two pairs of wings. The first pair, or wing covers, also 

 called tegmina, is attached to the dorsal region of the mesothorax. 

 They are leathery in texture and do not fold fanlike over the abdo- 

 men. They are strengthened by many veins and cross veins. The 

 second pair of wings is attached to the metathorax. They are mem- 

 branous, with many veins to strengthen them, and fold fanlike over 

 the abdomen when not in use. The metathoracic wings are used 

 in flight. 



The last main division of the insect body is the abdomen. It is 

 composed of eleven segments. The seven anterior segments are 

 similar in both the male and female. In the male the first abdominal 

 segment is made up of a curved dorsal shield, the tergum, which 

 terminates just above the attachment of the third pair of legs. This 

 piece partially surrounds the tympanic membrane, or ear, which is 

 a large, crescent-shaped area covered with a semitransparent mem- 

 brane. The ventral part of the first segment, the sternum, is not 

 attached to the tergum, owing to the large size of the attachment 

 of the legs. The pleura are entirely absent. The second to the 

 eighth segments are all quite similar, consisting of a dorsal tergum, 

 which extends laterally to near the ventral part of the body, where 

 it joins the sternum. The pleura, or side pieces, noted in connection 

 with the thorax, have been inseparably fused to the tergum. In 

 the ninth and tenth segments the terga are partially fused together, 

 the union of the two being indicated by the presence of a transverse 

 suture. The sterna of these two segments are entirely fused and 

 much modified, forming a broad, platelike piece. The eleventh 

 segment is represented only by the tergum, which forms the termi- 

 nal, dorsal, shield-shaped piece. 



The cerci constitute a pair of plates attached to the lateral posterior 

 border of the tenth segment, and extending back, past the end of 

 the eleventh tergum. The podical plates lie directly beneath the cerci 

 and ventral to the eleventh tergum. The anus opens between these 

 plates, and the genital chamber lies directly below them. Attached 

 to the ninth sternum is the suhgenital plate which forms the most 

 posterior ventral plate of the body. 



