DIVISION OF ENTOMOLOGY. 



The San Jose Scale and Experiments for 

 its Control* 



By H. T. FERNALD. 



It is probable that all the towns in Massachusetts east of the Con- 

 necticut River, and many of those west are infested more or less 

 with the San Jose' Scale. First discovered in the State about 1892, 

 it has become widely distributed since that time and has now 

 increased to such an extent as to be one of our most serious pests. 

 Indeed, in the opinion of many persons, it is even more dangerous 

 than the Gypsy and Brown-tail Moths, for though it actually destroys 

 fewer kinds of plants than the Gypsy Moth it is so small that its 

 presence is rarely noted till the work of destruction is well-nigh com- 

 pleted. Its method of feeding, too, is such, taken in connection 

 with its size, as to render successful treatment extremely difficult, and 

 the rapidity with which it increases in numbers is often sufficient to 

 cause the destruction of a tree in a single season. 



Calls for information as to the appearance, life history and habits 

 of this pest and the best methods for its control, at the present time 

 form quite a large part of the correspondence of the Division of 

 Entomology of this Station, and this bulletin has been prepared to 

 answer these calls, and also to give the results of such experitnental 

 studies on control as have thus far been made here. 



HISTORY. 



The San Jose' Scale is apparently a native of China, where it 

 seems to be held more or less in check by a tiny lady bird or lady 

 bug, Chilocorus similis, which feeds upon it. How it reached this 

 country is not known but it was discovered in the San Jose Valley in 



