California about 1879 and was named Aspidiotus peniiciosus by Prof. 

 J. H. Comstock who wrote at that time of it : — •' I think that it is the 

 most pernicious scale insect known in this country.'" A few years 

 later it was discovered in two New Jersey nurseries which had been 

 sending out large quantities of stock, and on this stock it was 

 undoubtedly distributed to nearly all parts of the United States. At 

 first it seemed probable that it would not live or at least become a 

 serious pest in the more northern states on account of the colder 

 climate there, but it appears to have gradually become more hardy, 

 and is now able to thrive in all parts of Massachusetts to a most 

 unfortunate degree. 



LIFE HISTORY AND APPEARANCE. 



The full grown San 

 Jose Scale is about the 

 size of a pin head, quite 

 Hat, round (circular) in 

 outline, and varying in 

 color, but usually gray- 

 ish brown. It lies 

 closely against the bark, 

 leaves or fruit and the 

 part seen is not reallv 

 the insect itself but the 

 shell or scale which cov- 

 ers it. If this scale be 

 lifted with a pin a very 

 small, o r a n g e-y e 1 1 o w 

 speck will be found 

 beneath it, and this is 

 the scale insect. 



When winter sets in, 



Different stages of the San Jose Scale enlarged live times ^^^ insects are present 

 (From Va. State Crop Pest Commission Bulletin, 1904.) in all Stages of growth 



from those just born to those which are full grown and are them- 

 selves producing young. The winter, however, kills all except those 

 which are from about one-half to two-thirds grown, so that no living 

 adults can usually be found in early spring. 



