CONTACT INSECT SPRAYS I99 



dition where it will readily mix with water when wanted for use, 

 and if this ' ' stock solution ' ' is made at the rate of two or three 

 pounds per gallon it is a very simple matter to prepare a batch 

 of spray for use in the orchard. It is generally used at the rate 

 of one pound of the soap to about 8 to 10 gallons of water. 



Kerosene emulsion is another very efficient remedy for such 

 insects as the aphis. The chief objection to it is that it requires 

 a special operation to make, but that is certainly not a serious 

 matter. The formula is as follows: 



Vy pound of hard soap, 1 gallon water, 2 gallons kerosene. 



Cut up the soap and dissolve it in the water by boiling. Then 

 remove from the fire and add the kerosene ; reheat and agitate 

 the mixture violently. A good way to do this is to have a small 

 pump, and pump the liquid back into itself until a creamy white 

 mixture is produced. This is a " stock solution," and ought to 

 keep for weeks or even months without the oil separating out. It 

 is diluted for use according to the insect to be attacked. With 

 aphids, which have very soft bodies, one part of the stock solution 

 to ten or even fifteen parts of water may be strong enough. For 

 tliose insects which are more difficult to kill, such as the San Jose 

 scale, it may require one part to four or five of water. 



Tobacco Extracts. — There are a number of tobacco extracts 

 on the market which are very satisfactory for sucking insects, 

 especially for the aphids. In the Northwest it is customary 

 in many sections, where the aphis is plentiful, to include some 

 form of tobacco extract with the regular sprayings for fungous 

 pests and chewung insects so that the spray kills sucking and 

 chewing insects and fungous diseases at one operation. 



Spreaders. — There are various products, usually with casein 

 as a basis, which are added to spraying mixtures with the object 

 of making them spread more evenly over the foliage and fruit. 

 At the present time they are coming quite largely into use and 

 seem to give not only better spreading of the materials, but greater 

 adhesiveness and less chemical action between such materials as 

 lime-sulfur and arsenate of lead. 



