94 ^'HE CONNECTICUT POMOLOGICAL SOCIETY. 



amount of copper sulphate which chugs to the inside of the 

 barrel is enough to cause a separation of the oil and water. 

 Lime and sulphur have a similar influence, but this mixture 

 acts more slowly. Neither arsenate of lead or Paris green 

 has shown any such tendency. 



The use of the agitator is not essential, but is recom- 

 mended, especially when only one or two nozzles are in use 

 and the emulsion is pumped out slowly. An occasional stir- 

 ring with a dasher of some kind will answer the purpose. 



Thoroughness of application is of utmost importance ; 

 every portion of the tree must be covered with a film of oil. 

 The spray should be expected to kill only those insects that 

 it touches. The progeny in one season from a single surviving 

 scale is enormous and may run up into the millions. In the 

 case of badly infested orchards two applications are recom- 

 mended, one in the fall and the other in the early spring. As 

 a regular practice, however, one thorough application a year 

 should keep the insect in check. With the use of a fine nozzle 

 and abundant power, more thorough and more economical 

 work may be done. Many insects hibernate under bud-scales, 

 and among plant hairs, and will escape the spray unless it is 

 applied with sufficient force through a fine nozzle. It is more 

 difficult to detect faulty work on the part of the operator with 

 oil than with lime and sulphur, and for this reason, the 

 spraying should be delegated to trusty men. With large apple 

 trees, one man should spray from the ground, to cover the 

 lower parts of the branches, and another from a tower on a 

 wagon to spray the upper surfaces of the lower branches. 



If a rain should occur within twenty-four hours after 

 spraying, or before the water in the emulsion has evaporated, 

 a second application may be necessary. After the water has 

 evaporated the oil is unaffected by the rain and will remain 

 until it also has evaporated. , 



Time to Spray. 

 Like the lime-sulphur wash, oil emulsion at regular 

 strength must be applied while the trees are dormant. The 

 insects that live over winter arc those of the last brood, which 



