ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



65 



there is no scale infestation, a dilution testing 3.5° Baume* is adequate 

 (table 1, p. 71) and may be applied at any time in the spring before 

 the pink stage of the blossom buds. Oil sprays are much less effective 

 and should not be used if the twig borer is at all serious. Sprays con- 

 taining 3 pounds of lead arsenate to 100 gallons of water, or nicotine 

 sulfate (40 percent nicotine) in the proportion of three-fourths of a 

 pint to 100 gallons of water, with soap or casein spreader, are also 

 effective if used just before full bloom, but ordinarily the dormant- 

 season application mentioned above constitutes a cheaper and more 

 satisfactory control. 



San Jose Scale 



The San Jose scale is not so serious on peach as on apple and pear, 

 and it seldom injures apricot. For a description of this insect and 

 methods of control, see page 9. Other insects that may be on the 

 trees at the same time should be taken into consideration, as the lime- 

 sulfur solution is al- 

 most necessary if the 

 peach twig borer is to 

 be combated, whereas 

 control of the green 

 peach aphid requires 

 an oil spray or a spray 

 containing nicotine. 



European Fruit 

 Lecanium 



The European 

 fruit lecanium attacks 

 peach and apricot 

 trees, as well as prunes 

 and other deciduous 

 fruits. For a discus- 

 sion of the life history 

 and control of this 

 insect, see page 51. 



Climbing 

 Cutworms 



Climbing cutworms 

 often destroy many of 

 the opening buds on 

 peach and apricot 

 trees in the spring (fig. 

 73). The injury is 

 more apparent than 

 the insects, since the 

 latter feed only at 



Figure 73. 



Peach buds showing holes made by 

 climbing cutworms. 



night and hide at the bases of the trees during the day. See page 31 

 for more information about the insects and their control. 



Peach Borer 



Although the peach borer is a serious pest of peach trees in Califor- 

 nia and the Eastern States, it does more injury to prune trees than to 



