INSECTS, HARMFUL AND OTHERWISE 



23s 



Katydid. 



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



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



also the three oceUi. 



The song of the ci- 

 cada is produced in a 



pair of elaborate drum- 



hke 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 ahve 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 

 Fig. 82. Cicada. from 13 to 1 7 ycars to mature. They 



hve 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. 



