The Bulletin. 11 



one pound to two gallons water. Put this over fire and bring to a boil 

 and then stir, which will cause the soap to dissolve in the hot water. 

 Now remove from the fire and pour in two gallons of cold water, and 

 it is ready to use. This gives one pound of soap to four gallons of water, 

 and will be fatal to all lice that are wetted by it. It is best applied 

 with a spray pump. As many of the lice will be hidden in wrinkles 

 of the leaves or on the under sides of the leaves it is not easy to reach 

 them all. It is a great advantage to have a boy (barefooted and with 

 sleeves rolled up), go along with the man who is doing the spraying, 

 to turn the leaves quickly from side to side, open and close, etc., so that 

 every inch of surface of every leaf will be reached by the spray. The 

 work can be done thoroughly and rapidly in this way. It is not nearly 

 so difficult as it may sound from this description. Many persons in 

 this State have used this cheap and simple remedy as result of our 

 recommendations and almost without exception they report good results. 



Prof. E. I. Smith, Entomologist of the North Carolina Experiment 

 Station, says :* "It is surprising how easy the cabbage lice may be killed 

 with soap solution. Ordinary strong potash washing soap, or powder, 

 will do the work. Dissolve one pound in about four gallons of water and 

 apply to infested plants with considerable force and in liberal quantities. 

 The lice are often so thickly massed together that those underneath 

 will escape unless the solution is applied as a fine spray and with force. 

 A spray pump is quite necessary and should be provided with a short 

 hose and extension rod with a curved end, in order to throw the spray 

 on the under side of the leaves. Failing in this, the leaves must be 

 turned over and the colonies of lice saturated. Simply sprinkling the 

 tops of infested plants does very little good." 



All of which is quite in accord with our experience and strengthens 

 the recommendations alreadv made. 



Other Remedies. — Kerosene emulsion at strengths of 10 to 15 per 

 cent oil has been recommended in some other States. Full directions 

 for preparing this are given on page 40. In some experiments which 

 we conducted at Raleigh in 1904, the emulsion at strength of 10 per 

 cent oil did not kill the lice as well as the soap solution already de- 

 scribed, while at 15 per cent oil, which did not kill the lice quite satisfac- 

 torily, there was a noticeable though not serious scorching of the leaves 

 after a few hours of warm sunshine. A spray solution of whale oil 

 soap has been suggested, but we do not know as the exact proportions 

 have been worked out. 



In 1905 a gentleman in Rutherford County reported that he had good 

 success in this way. He filled a barrel with wood ashes and poured in 

 water until it leached through at the bottom. This water had enough 

 lye so that when sprinkled or sprayed on the plants it was fatal to the 

 lice. 



From all this discussion of remedies the reader can see that the con- 

 trol of the cabbage louse is neither expensive nor difficult. The two 

 main points are, that it is killed by using solutions of soap, lye, or oil, 

 and that the application must be very thorough. 



•Bulletin 197, N. C. Exp. Sta., p. 18. 



