THE SAN JOSE SCALE. 
INTRODUCTION. 
Since the discovery of the San Jose scale in the East in August, 
1893, this insect has been the subject of almost continuous investiga- 
tions by the Division of Entomology. On account of the fact that its 
discovery was due to this office, that its probable wide distribution in 
the East was first appreciated here, and that this office first called the 
attention of fruit growers and experiment-station workers to the great 
danger which it threatened, and further, on account of the fact that 
the insect is of national importance, State and station entomologists 
have looked to this office for a complete investigation of the subject. 
This we have endeavored to carry out, and present herewith a compre- 
hensive summary of the results. 
Much that is printed here has already been published in one shape or 
another in Insect Life, and republished in experiment- station bulletins 
and agricultural newspapers, but most of the topics of importance 
have been considerably added to in this publication. The most com- 
plete life history hitherto published, for example, is that given on pages 
287-289, Volume VII, of Insect Life. Careful observations during an 
additional season have enabled us to make the present account much 
more complete. 
The chief work which remains to be done is remedial. The writers 
feel by no means satisfied that cheaper if not more efficacious washes 
will not be found. They will continue experimental work in this direc- 
tion, and in this work they count upon the cooperation of all experiment- 
station entomologists. 
IMPORTANCE OF THE INSECT. 
There is perhaps no insect capable of causing greater damage to fruit 
interests in the United States, or perhaps the world, than the San Jose, 
or pernicious, scale. It is not striking in appearance, and might often 
remain unrecognized, or at least misunderstood, and yet so steadily and 
relentlessly does it spread over practically all deciduous fruit trees — 
trunk, limbs, foliage, and fruit — that it is only a question of two or three 
years before the death of the plant attacked is brought about, and the 
possibility of injury, which, from experience with other scale enemies of 
