64 The Canadian Horticulturist. 



A NEW PEST— THE SAN JOSE SCALE. 



Aspidiotus perniciosus, Comstoek). 



^ HE unexpected discovery, in the Eastern United States and British 

 Columbia, of this scourge of the Pacific Coast orchards, makes 

 it all important to draw the attention of Ontario fruit growers to 

 the subject, so that they may become familiar with its appearance 

 and be prepared to adopt active measures to eradicate it, should 

 it, as it is more than probable, appear in our province. 



In August, 1893, the first eastern specimens of the San Jose 

 scale were brought to the notice of the United States Entomo- 

 logist, and he at once took active measures to find out all that 

 was to be learned concerning its distribution and injuries, with the object of 

 stamping out such a formidable enemy. In April, 1894, Mr. Howard issued 

 a circular under the caption " An Important Enemy to Fruit Trees," in which 

 he gave a short history of the insect and the most approved remedies. He has 

 been kind enough to lend the following illustration from that Bulletin, which 

 will be of great service in giving an idea of the appearance of the insect. 



The San Jose Scale was first brought to California, it is thought, from 

 Chili, about 1870, and it was first noticed as injuriously abundant at San Jose 

 in 1873, and called the San Josd Scale. '' It does not seein to have been named 

 scientifically until 1880, when Prof. Comstock described it in his annual report 

 to the United States Department of Agriculture — he designated it perniciosus, 

 because he considered it the most pernicious scale insect known in the country. 

 It swarmed in countless numbers upon the trees in certain orchards, and infested 

 all the deciduous fruits grown in California, except the apricot and Black Tar- 

 tarian 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 Wash- 

 ington. It is known as the worst insect pest of deciduous 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." (L. O. Howard, Cir- 

 cular 3.) 



In 1892 the insect was found in New Mexico, on apple, pear, plum, peach, 

 quince and rose. It had been brought into New Mexico upon young trees 

 from California. Nearly all the other instances of infestation east of the Rocky 

 Mountains can be traced to two nurseries in New Jersey, where the pest had 

 been introduced in 1886 or 1887 on trees of the Japanese plum " Kelsey," 

 which had been procured from the San Jose' district in California. Idaho pear 

 trees had also been frequently imported from California, which were most pro- 

 bably infested. In 1891 and 1892 several blocks of young apple trees were 

 badly infested. It is on pear trees chiefly that this pernicious scale has been 



