86 DECIDUOUS FRUIT IXSECTS AND INSECTICIDES. 



now conceded to be the best tools in use. A combined scraper, 

 chisel, and rounded worming blade has been used extensively, but 

 tools of this kind do not contain the fine quality of steel that is found 

 in other knives and chisels and they soon become dull. The bark is 

 often broken rather than cut when such tools are used, and this works 

 serious injury to the tree. The curved worming blade is especially 

 harmful, because it is forced into the burrow and great pieces of liv- 

 ing as well as dead bark are broken off. The tool is convenient 

 because it combines the scraper, chisel, and worming point, but its 

 convenience can not offset the better work of the ordinary chisel and 

 knife. 



There are two periods during the whiter and the spring months 

 when worming can be done to advantage. Worms are from half to 

 full grown and can be easily seen during the winter. They are more 

 or less dormant, and if cut out at this time the trees will be spared 

 the later injury which would follow their feeding during the spring. 

 It is also more convenient to orchardists to dig for borers at this 

 time because of a freedom from other work. Spring worming is also 

 quite as effective as when this work is done during the fall. A pro- 

 tective wash should be applied after "worming'" has been accom- 

 plished. Such a wash acts primarily as a repellent and keeps adult 

 moths from placing their eggs on such treated trees. This wash 

 should be applied during the months of May or early June, when 

 moths are beginning to fly. If the wash is applied after worming in 

 the fall it deteriorates and cracks and falls away from the tree before 

 the time when oviposition occurs. It is considered just as good 

 practice to dig the borers dining the fall as in the spring, but in any 

 case the wash should again be applied in May or early June. The 

 wash also serves in a secondary way to render the labor of subse- 

 quent worming much more easy and rapid. The dirt and bark 

 scalings fall from the washed tree more easily than from those 

 unwashed, and the masses of frass, indicating the presence of borers, 

 are also more easily discovered. 



FORMULAS FOR WASHES USED. 



The following washes have been used extensively for controlling 

 borers in the Santa Clara Yallev and elsewhere: 



Formula No. 1. — The lime-crude oil mixture: Place about 50 pounds of rock lime 

 in a barrel and slake with 10 or 15 gallons of warm water; while the lime is boiling, 

 slowly pour in 6 or 8 gallons of heavy crude oil, and stir thoroughly. Add enough 

 water to make the whole a heavy paste. The wash should be applied immediately 

 with a heavy brush. 



Formula No. 2. — The lime-sulphur-salt mixture: Place about 25 pounds of rock 

 lime in a barrel and slake with warm water. Add 2 quarts of sulphur and 2 or 3 hand- 

 fuls of salt while the lime is still boiling. This wash is heavy and is applied with 

 a brush . 



