INSKCTS AND DISKASKS OK TIIK PKACII 



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main burrow runs around the limb while the laterals run length- 

 wise of the branch. Thus the sap supply is cut off, and the 



exudation is greater. In western New York this species attacks 



healthy trees to a greater extent than does the closely allied 



species, Scolytus ruguLosis. 

 The latter species seems to 



prefer dead, or partially dead, 



wood and does not as often 



attack healthy trees. The 



adults of this species make 



vertical bores in the bark, and 



although the larvae begin by 



boring along the sides of the 



vertical channel, they gradu- 

 ally curve their course and go 



more or less lengthwise of the 



limb. In Fig. '349, the course 



of the main chamber and the 



vertical tendency of the lateral 



bores should be noted. 



Measure of Control. Since 



both borers cause considerable 



loss of peach trees in peach 



sections, it is wise for growers 



to ward against having a 



breeding ground in the vicin- 

 ity of a peach orchard. The 



writer has often seen peach 

 tumps piled on one side of 



the orchard and left until fall, 

 'he borers had bred in the bark of the stumps or brush if the 



source happened to be from brush, and about September first, had 



migrated from the dry peach wood to healthy or weak trees nearest 



to the pile. 



In the western part of the state, examination was made in one 



instance of borers that had migrated from a pile of peach brush 



lortheast of a three-year-old orchard to trees on the northeast 

 >rner of that orchard. The infestation was heavy, and the boring 



FIG. 349. CHANNELS MADE BY THE 

 SHOT-HOLE BORER (Phlceotribus 

 liminaris ) 



