INTRODUCTION. 9 
On the whole, the danger of the scale becoming distributed by 
means of fruit is seen to be quite unimportant, and in the United 
States, where legislation against injurious insects finds its greatest 
development, this source of possible distribution, with a few excep- 
tions, is ignored. The possibility, however, under certain excep- 
tional conditions must be admitted, and this danger has appeared 
sufficient to warrant certain European governments in enacting 
legislation excluding from entry all fruits from America which show 
upon inspection the presence of the San Jose scale, including boxes, 
barrels, wrappings, etc., used for packing such fruit. 
In the United States the scale each year is becoming more and 
more generally distributed, and the pest is now present in sections 
which were until recently quite free from it. In the Western and 
Eastern States it is especially prevalent, and while there are numerous 
orchards and fruit regions still uninfested, these will unquestionably 
be invaded. The States least infested are those immediately west 
of the Mississippi River, as Iowa, Kansas, Arkansas, etc., but in 
these the scale has also gained a foothold and its general spread in 
these States seems certain. In other words, the scale is now, or in a 
few years will be, present in the principal commercial orchards of the 
country, and the appearance on the market of fruit infested by the 
insect is an evil which will increase rather than diminish. 
The intelligent use of lime-sulphur wash, or other effective scalecide, 
will unquestionably control the insect so far as preserving the life 
and vigor of the tree is concerned. But a little carelessness in spray- 
ing, the use of improper solutions, or unfavorable weather conditions 
at the time of making applications, may allow the survival of the scale 
in sufficient numbers to result, later in the season, in their settling in 
considerable numbers upon the fruit. The use of the lime-sulphur 
wash, perhaps, actually favors this condition.* It has but little 
penetrating and spreading power and may fail to kill some of the 
insects, especially on the younger growth where they are more or 
less protected by the pubesence or fine epidermal hairs. Young 
“lice” from insects which have thus escaped destruction, and from 
those elsewhere on the tree, upon hatching, are probably forced, in 
their search for a suitable place for settlement, upon the fruit, if this 
be present, on account of the coating of the wash upon the tree. The 
young crawling insects settle principally in the calyx basin and stem 
cavity of the fruit, although they are often in abundance promis- 
cuously over the sides, as shown in Plates I and II. If infestation 
occur in early summer the fruit at picking time, in extreme cases, 
may be more or less incrusted with the insect; in well-sprayed 
orchards it should be present in but few or moderate numbers. The 
greatest pains should be taken by orchardists whose trees are infested 
a See also remarks on this subject by C. L. Marlatt, in Bul. 46 of this Bureau, pp. 
54-55. 
