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 
Fic. 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 aduits 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. 
Fic. 346.— The Periodical Cicada. 
Original. 
The San José 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 
