12 



CROP PEST COMMISSION OF 



by this insect rarely survive to exceed three or four years and 

 their productive capacity, if they are allowed to remain untreat- 

 ed, is often seriously impaired by the second season of infesta- 

 tion. 



The San Jose scale is known to occur upon a great variety 

 of trees and plants. Mrs. H. T. Fernald, in her "Catalogue of 

 Coccidae"* gives a list of sixty-five different plants upon which 

 this insect has been found. Upon the majority its occurrence is 

 only occasional, and it cannot be considered a serious pest to more 

 than a few of them. In the South, severe infestations may be 



PIG. 8. Adult male San Jose scale much enlarged. (After Howard and 

 Marlatt, Bui. No. 3, n. ser., Div. of Entomology, U. S. Dept. of Agriculture.) 



looked for upon all varieties of apples, plums, and peaches as well 

 as upon cottonwood, Carolina poplar, Bois D 'Arc and the hardy 

 orange (Citrus trifoliata). While it is frequently a most serious 

 pest of pear trees in the North, it apparently does not thrive as 

 veil upon the pear in the South, although pear trees are occa- 

 sionally found that have their growth and productive capacity 

 severely impaired by the attacks of the scale. Carolina poplar 

 trees often become very heavily infested, but owing to the vigor- 

 ous growth of this tree it usually outgrows, in a sense, the at- 

 tacks of the scale. 



* Bulletin HK. Hatch Exp. Station of Mass. 



