INSECTS, HARMFUL AND OTHERWISE 



2 35 



FIG. 81. Katydid. 



terminated by a stout, sharp beak, which is generally folded 

 under the head. The compound eyes are prominent, as are 

 also the three ocelli. 



The song of the ci- 

 cada is produced in a 

 pair of elaborate drum- 

 like organs on the under 

 side of the abdomen. 

 Turn the insect over 

 and a pair of circular 

 covers will be seen just 

 behind the hind legs. 

 Lift these up and you 

 will see a cavity under 

 each. Across this cavity are stretched membranes which 

 are made to vibrate by the rapid contraction and relaxation 

 of attached muscles. The females have 

 no such sounding apparatus and are 

 therefore silent. 



If cicadas are found that have dropped 

 from the trees they should be brought to 

 the school alive and kept in cages. Feed 

 them on succulent leaves. 



The development of the so-called 

 seventeen-year cicada is interesting be- 

 cause the larvae grow very slowly, taking 

 from 13 to 17 years to mature. They 

 live in the ground, feeding upon tender roots. The two-year 

 cicada develops in two or three years. 



Cicadas have been famed in poetry ever since the times of 

 Homer. 



FIG. 82. Cicada. 



