Explanation of Plate I. 



The San Jose Scale, Aspidiotus perniciosus Comst. 



I. A pear infested by the scale. 



II. a — g. Male scales showing the variations in the color and markings. 



III. Female scale. 



lY. Adult female. 



V. Newly hatched larva. 



VI. A group of male and female scales. 



