THE CALIFORNIA PEACH BORER. 87 



Formula No. 3. — Lime, coal tar, and whale-oil soap: Unslaked lime 50 pounds, 

 coal tar 1£ gallons, whale-oil soap 12 pounds. Slake the lime in warm water and add 

 the gas tar while the mixture is boiling; dissolve the soap separately in hot water 

 and add this to the lime solution. Add enough water to make a heavy paste. 



THE CARBON BISULPHID TREATMENT. 



Carbon bisulphid has been recommended extensively, but its use is 

 now discouraged. Moisture conditions in the soil are so variable that 

 no set rule to determine the amount of liquid which shall be used can 

 be followed, and if the treatment should be preceded by a rain, or if 

 the ground be especially damp, the gas-treated soil can not be left 

 around the tree without immediate injury. The carbon bisulphid 

 method has been more or less successful when an orchardist has done 

 his own work for several years and when he himself places the charge 

 and recognizes the danger. Serious damage is most likely to follow if 

 the remedy is applied by an inexperienced man. Another disadvan- 

 tage of the carbon bisulphid treatment is that it does not remove the 

 dead or decaying bark above after the cambium layers have been 

 killed by the borers. Hand cutting is never practiced after this treat- 

 ment, and the tree can never heal its wound as it does when the dead 

 bark is cut away. 



METHODS USED AGAINST THE EASTERN PEACH BORER. 



Some of the methods of treating the eastern peach borer have been 

 used, but with little success. Paris green and glue washes have nearly 

 always injured the trees. Paris green is not valuable as an insecticide 

 against borers because the larvae do not take any part of the wash 

 directly into their stomachs. Hydraulic cement has been used for 

 the purpose of placing a hard coating over the bark so the borers can 

 not penetrate through into the tree. It has been used apparently 

 with only negative results. The hard covering of cement cracks 

 easily as the tree expands and offers little or no resistance to the 

 borers. Numerous combinations of rosin and white or green paints 

 have proved of no value, and there usually follows some injury to the 

 trees. "Mounding" as practiced in the Eastern States consists in 

 building up a cone-shaped pile of dirt around the lower trunks. This 

 is done during the early spring or summer, and its object is to force 

 moths to oviposit high up in the crown of the trees. The young larvae 

 are thus deceived and enter the bark usually high up under this loose 

 soil and are easily exposed when later the mound of dirt is removed. 

 This method is not practiced against the California peach borer, 

 although it might be used with success. Surrounding the tree with 

 paper or other wrappings has been practiced commonly in the East, 

 but not successfully in California. The long, dry California summers', 

 which necessitate constant spring and summer cultivation, tend to 

 lessen the effectiveness of such wrapping or mounding. 



