167 
DCXIIL—SAN JOSE SCALE. 
A plant-pest known under the above name has recently attracted 
a good deal of attention in the United States and Canada, as we 
griculture.* The original home of a scale (Aspidiotus 
perniciosus) is at present unknown. It was observed in an 
epidemic form in the San Jose Valley in California, about 1870. 
Since then it has rapidly spread in every direction in the United 
States. The seriousness of its attacks may be gathered from the 
following extrac 
“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 i in appearance, 
all deciduous fruit trees—trunk, li mbs, 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 dieses d of eii 
which, from experience with other scale enemies of deciduo 
plants, might be easily ignored or etn insignificant a vote 
startlingly demonstrated. Itsimportance from an econ 
point, is vastly increased by the ease with which it is distributed 
over wide districts through the agency of nursery stock and the 
imabketing of fruit, and the extreme difficulty of exterminating 
it where once introduced, presenting, as it does i in the ge regard, 
difficulties not found with a any other scale insect.” (l.c. pp. 9-10.) 
Aspidiotus PEE belongs to the sub-family Dipl of 
mu Coccide. It is mall soft insect which secretes a scale 
rate from itself uh Jike the shell of an oyster. This scale 
is ve minute, round, flattened, and in the case of the me is 
“ grayish, hardly bla ck, a a light + dot : and ring.” 
The illustrations reproduce ed in the Gardeners’ Chronicle 
(Feb. 12, 1898, p. bue - BA. will afford some idea of t 
appearance of the . 87 it is on a Californian pear 
the United States the insect is known to occur in 
han Chile and Hawaii. It is now spread throughout the 
States of California, Oregon and loge reaching British 
Columbia during the last few years. It has extended southward 
to Ne aan Arizona and New Mexico. In the usar States its 
occurrence has in many cases been traced to two large New Jersey 
nurseries i4 fiom which infested plants had unwittingly been sent 
out for certainly six or seven years.” The Southern States, such 
San Jose scale has in a we years gai ined a foothold in no le 
than fourteen States east of the Rocky x HRSG Its latitudinal 
range extends from 28? S. lat., to 50° N. 1 
* The San J 
of its life history and the rétiediol to be eed gaia it. By L. O. Howard and 
C. L. Marlatt. Bulletin No. 3. New Series. United States Department of 
ieulture, i tote x. atem logy. Wi th a map and numerous woodcuts, 
