538 ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
the San Jose scale, however, and fur- 
nishes a fairly sure basis for identifica- 
tion in the orchard. 
The condition of the scales can readily 
be ascertained by scraping them from a 
branch; if they are dead, the scales will 
rub off like a dry, gray scurf; if they are 
alive, the crushed bodies will produce a 
yellow oil-like fluid which gives the bark 
a greasy appearance. Wherever a scale 
has settled there will be a small round 
spot with a white speck in the middle; 
the spot is formed by the body of the 
scale while the white speck is where the 
long thread-like piercing apparatus, or 
tongue, was inserted in the bark. Often- 
times the seales will completely cover 
portions of limbs and overlap on each 
other so that they form a crust. When 
so badly infested, young scales will crawl 
under old dead scales and settle. We 
have found as many as four young scales 
fastened side by side under one old scale. 
Fruit infested with the scale becomes 
pitted and gnarled, as the growth is 
checked at the point where the scales 
have their beaks inserted. 
“For the benefit of fruit inspectors in 
particular, it should be noted that reddish 
discolorations upon yellow fruit are not 
always caused by San Jose scale. Upon 
yellow apples and particularly upon 
peaches very similar spots are produced 
by attacks of certain minute fungi. Hence, 
such spots should not in themselves be 
taken as proof of infestation by the scale. 
This can be determined definitely only by 
a careful examination and the actual de- 
tection of the scale. The presence of such 
blotches may well arouse suspicion of the 
presence of San Jose scale and should 
challenge a careful examination alike by 
growers, buyers and inspector; so, also, 
should the presence of dead and shriveled 
leaves upon the trees in mid-winter invite 
examination, for, although their presence 
is not proof of the appearance of the 
scale, it is evidence that the vitality of 
the tree has been seriously impaired by 
some cause, and in regions where San Jose 
scale is prevalent that cause, in a vast 
majority of instances, is the scale.” (1) 
(1) A. B. Cordley, Bull. 88, Ore. Agr’l Ex. 
Sta.. p. 6, March, 1906. 
Unlike most other scale insects, it de- 
velops and hatches its eggs within the 
body, so that the young are born alive. 
In May, possibly earlier, under favorable 
conditions, the females begin to give birth 
to living young and may continue to pro- 
duce for six weeks or longer. 
General Description 
The young are minute, light orange 
yellow, active creatures with eyes, bris- 
tle-like mouth parts, two antennae or 
San Jose Scale on Apple Limb. 
(Purdue Bulletin 138.) 
Fig. 2. 
