254 



PESTS OF ORCHARD AND SMALL FRUITS 



sounding its long, high-pitched note in summer. Usually the only- 

 notable cases of injury are to newly set fruit trees, which are so small 



Fig. 345. — Emergence of Adult Cicada from pupal skin. Original. 



as to make the work in the twigs really serious. The injury takes 

 the form of a row of regular punctures in the twig, each puncture 



with a frayed or torn margin. 



Definite " broods " of this insect 

 exist in various parts of the 

 country, and these have been 

 studied and mapped so that the 

 coming of the adults can be pre- 

 dicted. The immature stages of 

 the cicada are passed in the soil, 

 and either 13 or 17 years are re- 

 quired for this part of the insect's 

 growth, depending on the section and the brood. At the end of this 

 time the adults suddenly appear in large numbers, lay eggs, and 

 another life cycle begins, as before. 



Bordeaux mixture appears to act as a repellent when sprayed on 

 young trees that are threatened with injury. 



The San Jose Scale {Aspidiotus perniciosus Comst.) 

 This serious pest of fruit trees, shade trees, and ornamentals is an 

 insidious insect, and seldom is recognized until it has gained a foothold 

 and has already caused marked injury. The first evidence of its pres- 

 ence usually noted is the weakening or dying of twigs. On further 



Fig. 346. — The Periodical Cicada. 

 Original. 



