THE SAN JOSE OR CHINESE SCALE. 



INTRODUCTION. 



The San Jose scale is now known to be of Chinese origin. Its name 

 is derived from its first point of colonization in America, namely, at 

 San Jose, Cal., and is, in a sense, undesirable, as giving an unmerited 

 notoriety to the district in California which had the misfortune of 

 being the accidental place to first harbor it. A more appropriate des- 

 ignation is the Chinese scale^ but it is improbable that a new name will 

 ever be adopted for an insect which has become so thoroly well known 

 and exploited under its original designation. 



Probably no other insect has had so much notoriety as has this spe- 

 cies, and certainly none has assumed so great an international impor- 

 tance, as indicated by the vast amount of interstate and foreign 

 legislation which has been enacted relative to it. In all the earlier 

 publications of this office, beginning with Comstock's original descrip- 

 tion and note in the Report of the Department of Agriculture for 1880, 

 the very great economic importance and capacity for harm of this 

 scale insect has been commented upon and the fact that there is per- 

 haps no insect capable of causing greater damage to fruit interests in 

 the United States than the San efose or pernicious scale. 



It is mconspicuous and often for a time passes unnoticed or unrecog- 

 nized. Meanwhile its enormous fecundity enables it to overspread the 

 trunk, limbs, foliage, and fruit of the tree attacked (Pis. I, VI), so 

 that it is only a question of two or three years, unless proper remedial 

 steps be taken, before the condition of the plant becomes hopeless or 

 its death is brought about. In capacity for harm this species probably 

 exceeds any other scale insect known, and it attacks practically all 

 deciduous plants, both those grown for fruit and the ornamentals. Its 

 economic importance is further increased by the ease with which it is 

 distributed over wide districts thru the agency of nursery stock, 

 and the difficult}^ and, as a rule, impossibility of exterminating it where 

 once introduced. Its capacity for evil, which was recognized in its 

 earlier work on the Pacific coast, was at once even more strikingly 

 demonstrated on its first appearance in the East, and before measures 

 of control were undertaken it was much more disastrous in peach 

 orchards of Maryland, New Jersey, and other eastern and southern 

 States than in California and the West. 



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