EXPERIMENT STATION BULLETINS. 265 



"The pot, jug, etc., must never be used for any other purpose after using it for mak- 

 ing this mixture." 



If an additional pound or two of lime be added to the mixture it will help to make 

 the application permanent and conspicuous without in any way interfering with its 

 efi'ect. In using it the extra lime is often added. 



CONTACT INSECTICIDES FOR INSECTS WHICH SUCK THEIR EOOD. 



The most effective contact insecticides are kerosene emulsion and whale-oil soap. 

 Kerosene emulsion may be used against all lice (except bark lice), bugs, etc., which 

 do not succumb to the internal poisons. To be effective it must be very carefully made 

 and conscientiously applied. 



Place two gallons of ordinary kerosene in a warm place, either in a warm room or 

 in the sun, and allow it to become as warm as possible without danger from fire. 

 Boil one pound of laundry soap or whale-oil soap in a gallon of soft water until 

 completely dissolved. If the water is the least bit hard, "break" it with washing soda. 

 Remove the soap solution from the fire, and while still boiling hot add the kerosene 

 and agitate for ten minues, or until the oil is emulsified, with a spraying pump, by 

 forcing the liquid back into the vessel from which it was pumped. 



When the liquid is perfectly emulsified it will appear creamy in color and will flow 

 evenly down the side of the vessel. Care should be taken to completely emulsify the 

 oil. and this is accomplished much more easily when the mixture is hot. This strong 

 emulsion may now readily be diluted with water and used, or it may be stored away for 

 future use. When cold it becomes like sour milk in appearance, and should be dissolved 

 in three or four times its bulk of hot water before diluting with cold water. 



Small amounts of this emulsion may be made by using the ingredients in small 

 quantities, but in the same relative proportion. 



It should be diluted ten times for most insects, but many plants are able to resist 

 a stronger mixture, which is usually more effective. 



KEROSENE AND WATER. 



Kerosene and water applied with a special pump, designed for the purpose, has 

 sometimes been substituted for kerosene emulsion, when a large amount of work is to be 

 done in the winter time against scale insects. This method of spraying would have 

 obvious advantages if it were entirely safe. Very contradictory results have been 

 obtained with tliis spray, and if anyone intends to use it, let him proceed with due 

 caution and apply it in a small way several times before using it at all extensively. 

 This application never should be made except on a bright sunshiny day, when the 

 evaporation is rapid, otherwise the oil will strike into the tree and kill it. The oil 

 used should be quite a high test oil as well. 



A pump suitable for applying this mixture takes the oil from one tank and the 

 water from another, mixing them as they pass through the pump and no7;zle, and 

 furnishing a spray that resembles ordinary emulsion, milky in appearance, but which 

 does not remain for so long a time in combination. The oil soon collects and rises 

 froin the water, and for this reason it is more dangerous on any but sunshiny days, 

 when it will evaporate quickly after being applied. Great care nuist be taken that the 

 pump is doing its duty and that it does not produce a varying spray. This should be 

 tested from time to time by catching some of the spray and putting it in a tall glass 

 to let the oil and the water separate. 



The application should not be made with more than 20 per cent of oil or one 

 part of oil to five of water, and tlie writer would discourage the use of tliis mix- 

 ture on the peach until we know more of its behavior. 



Prof. V. H. Lowe, entomologist of the New York Agricultural Exijeriment Station 

 at Geneva, New York, writes me that his experiments have led him to believe the use 

 of this mixture to be yet in an experimental stage, and that his results have been 

 very conflicting and at times fatal to the tree. 



The results here have been more encouraging, though the experiments have not been 

 extensive enough to base nuich faith on them. 

 34 



