Fig. 11-38. In some insects the appendages are utilized in making sounds. The common field crici<et produces its 

 familiar chirp by rubbing its posterior legs against its wings. This is a female; note its long ovipositors. 



Fig. 11-39. The cicada produces its shrill song (only the males sing) by a specially designed sound-making appa- 

 ratus. It consists of two sets of vibrating plates located on the ventral side of the abdomen. The right one can 

 be seen opposite the tibia of the posterior leg in this photograph. 



