INSECTS PARTICULARLY AKKKCTINQ THE APTLK 



843 



SAN JOSE SCALE 



The San Jose scale, Aspidi- 

 otus perniciosus Comst., is well 

 established in various sections 

 of the state. It is easily recog- 

 ni/ed by the dark grayish or 

 yellowish areas on the bark, 

 caused by the masses of old 

 scales or by the grayish black 

 of the young scales. The full- 

 grown, insect is nearly circular, 

 with a diameter of approxi- 

 mately one-sixteenth of an inch, 

 grayish, and with a central, 

 darker nip( e. The smaller 

 scales are about half the size 

 and are nearly black, while the 

 crawling young appear to the 

 naked eye as minute, yellowish 

 specks. 



The most characteristic sign 

 of infestation by this insect is 

 the dark reddish or magenta 

 stain in the greenish tissues of 

 the fruit, the leaves, or the 

 inner bark, as the case may be. 

 With the apple an infestation 

 is most likely to appear on the 

 fruit. 



The scale insect winters in a 

 partly grown condition. On 

 tlio approach of warm weather vital activities are resumed, and 

 crawling young begin to appear toward the last of June. The 

 females continue to produce young for a period of about six 

 weeks, each averaging about four hundred, or from nine to ten 

 every twenty-four hours. The life cycle is completed in from 

 thirty-three to forty days and, practically speaking, there is al- 

 most continuous breeding from the time the young appear in the 

 latter part of June until frosts check the process in the fall. 



FIG. 230. .SAN JOSE SCALE. TWIG 

 BADLY INFECTED, SHOWING THE 

 IRREGULAR, CIRCULAR HOLES 

 MADE BY THE PARASITES, EN- 

 LARGED FOUR DIAMETERS 



