594 Report of Entomologists of the 



emulsion at this time than during the winter. But the eggs con- 

 tinue to hatch for nearly a month, making several applications of 

 the emulsion necessary in order to insure thoroughness in the work. 

 The foliage also interferes with the thorough drenching of the limbs 

 and twigs. However, a number of infested plum trees in an orchard 

 at Geneva were sprayed early in July, as follows : 



Experiment No. 1. — July 3 (1895), 16 trees were sprayed with 

 kerosene emulsion, diluted with six parts of water. 



Experiment No. 2. — Resin wash. In the same orchard 16 trees 

 were sprayed July 3 with rosin wash, made after the following 

 foiTnula : 



Resin 20 pounds. 



Caustic soda (78 per cent.) 5 pounds. 



Fish oil 21^ pounds. 



Water to make 100 gallons. 



Directions for making this wash are given by Mr. Marlatt, 

 Farmers' Bulletin, ]^o. 19, U. S. Dept., Agr. p. 13, as follows : 

 " Place these substances with the oil in a kettle with water to cover 

 them to a depth of three or four inches. Boil for one or two hours, 

 making occasional additions of water, or until the compound 

 resembles very strong black coffee. Dilute to one-third the final 

 bulk with hot water, or with cold water added slowly over the :Qre, 

 making a stock mixture to be diluted to the full amount as used. 

 When sprayed the mixture should be perfectly fluid, without 

 sediment, and should any appear in tlie stock mixture reheating 

 should be resorted to." 



Results. — September 10, all of the trees sprayed in the above two 

 experiments were carefully examined. About 80 per cent, of the 

 scales had been killed on trees sprayed with either kerosene emul- 

 sion or resin wasli. The failure to kill all of them was undoubtedly 

 due to the fact that most of the scales were on the under sides of 

 the leaves and hence it was very difficult to reach them with the 

 spray. 



Conclusions and ^Recommendations Concerning Remedies, 



Kerosene emulsion is the cheapest and most practical insecticide 

 for the New York Plum Lecanium. 



All things considered, the best time to spray is during the winter. 



