560 Animal Biology 



(Fig. 292) spends over sixteen years of its life history as a larva in the 

 soil. During the seventeenth year, the adult emerges and deposits eggs 

 in the branches of trees, particularly fruit trees. The branches fall to 

 the ground, where the eggs hatch into larvae, there to remain for an- 

 other sixteen years. The destruction of the branches of trees by the 

 egg-depositing process is very great. Sometimes all of the smaller 

 branches are so badly punctured that they drop to the ground or at 



C. 



B. 



Fig. 290. — San Jose scale of the order Homoptera. A, Adult wingless female, 

 ventral view, showing very long sucking setae; B, bark of tree showing young 

 larvae and scales in various stages of development. The adult male, C, is winged. 

 All much enlarged. (From Marlatt: The San Jose or Chinese Scale, U. S. 

 Department of ^Agriculture ; courtesy of Department of Entomology and Plant 

 Quarantine.) 



least die on the tree. All these branches should be removed and burned 

 to destroy the eggs. The common cicada or harvest fly does damage 

 by eating vegetation, although not to such an extent as the periodical 

 17-year cicada. 



