INTRODUCTION. \) 



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. a 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 Bui. 46 of this Bureau, pp. 

 54-55. 



