1908] 
The San Jose Scale 
53 
research , one of our most beneficent functions will be missed if we 
fail at the same time to have on our programs a certain number 
of popular discussions of matters of economic importance to our 
state. 
So much by way of apology for discussing before this body a 
subject which to economic entomologists at least, has become 
threadbare and almost barren of new thoughts. 
* * * 
The San Jose Scale (Aspidiotus perniciosus) was first described 
to science in 1880 by Prof. J. H. Comstock, who found it very 
destructive in deciduous fruit orchards in the Santa Clara valley of 
California. He recognized it as one of the so-called “Scale- 
insects”, belonging to the genus Aspidiotus , remarking that it was 
the most pernicious scale-insect known to him, and therefore 
applying to it the specific name of perniciosus , and proposed that 
it be called the Perniciosus Scale. But as the city of San Jose is 
not distant from the place where it was discovered it became 
known by the popular designation of The San Jose Scale. 
There is reason to believe that it became established in Califor- 
nia as early as 1870/ and there is reason also to believe that it 
was introduced into California from China, which seems to have 
been its original home. 
In the eastern United States the insect was not known until 
1893 (only fifteen years ago) when it was discovered at Charlottes- 
ville, Va. on trees which had been purchased from New Jersey 
nurseries and these nurseries had presumably become infested by 
the importation of stock from California. Only four or five years 
later it was known to exist in twenty states east of the Mississippi 
river. It is not to be supposed that Charlottesville, and the New 
Jersey nurseries, were the only sources of scale in the east. It is 
likely that it became established in many other localities and per- 
haps in other nurseries at about the same time. 
So far as we know the San Jose Scale gained its first foot-hold 
in North Carolina at or near Southern Pines, Moore County, 
about 1893 or 1894, approximately at the same time that it was 
discovered at Charlottesville. It was not recognized until 1895 at 
