SB 
818 
e578 
ENT 
No. 3, SECOND SERIES. 
United States Department of Agriculture. 
DIVISION OF ENTOMOLOGY. 
AN IMPORTANT ENEMY TO FRUIT TREES. 
THE SAN JOSE SCALE; ITS APPEARANCE IN THE EASTERN UNITED STATES 
MEASURES TO BE TAKEN TO PREVENT ITS SPREAD AND TO DESTROY IT. 
SPREAD OF THE SPECIES IN CALIFORNIA AND DAMAGE DONE BY IT 
ON THE PACIFIC COAST. 
According to the most trustworthy authority, the San José Scale was 
first brought to California from Chile on trees received by Mr. James 
Lick, about 1870. Fruit shippers first noticed it in 1873 at San José, 
from which fact the popular name of the insect is derived. It spread 
rapidly until 1880, when Prof. J. H. Comstock, formerly Entomologist 
to this Department, collected specimens in Santa Clara County, and in 
the Annual Report of the Department for that year described it scien- 
tifically as Aspidiotus perniciosus. The specific name was given to it 
for the reason that Prof. Comstock considered it to be the most perni- 
cious scale-insect known in this country. -It swarmed in countless 
numbers upon the trees in certain orchards, and infested all the decid- 
uous fruits grown in California, except the Apricot and Black Tartarian 
Cherry. In the course of twelve years the insect spread through all 
the fruit-growing regions of California, through Oregon, and into the 
State of Washington. It is known as the worst insect pest of decidu- 
ous fruit trees on the Pacific coast, and has caused great pecuniary loss. 
Many crops of fruit have been ruined, and thousands of trees have 
been killed. 
OCCURRENCES OF THE SCALE EAST OF THE ROCKY MOUNTAINS. 
In 1892 the insect was found in the vicinity of Las Cruces, N. Mex., 
upon Apple, Pear, Plum, Peach, Quince, and Rose. It- had been 
brought into New Mexico upon young trees from California. In the 
summer of 1893 specimens of pears affected by the insect were received 
at the Department from Charlottesville, Va., and an investigation 
showed that a small orchard there was badly infested, the insect having 
32564— No. 3—06 
