1906 ENTOMOLOGICAL SOCIETY. 29 



Put 5 or 6 gallons of hot water in a wooden barrel, add the lime, quickly 

 following with ihe sulphur and sal soda, and stir until the slaking is practi- 

 cally completed. It may be necessary to add a little cold water at intervals 

 to keep the mixture from boiling over. After the violent action has ceased, 

 cover the barrel to retain the heat and allow it to stand 15 to 30 minutes, 

 dilute to the full quantity and apply. 



Formula No. 3. (Geneva formula). 

 30 pounds of good stone lime. 

 15 pounds of flowers of sulphur. 

 4-6 pounds of caustic soda. 

 40 gallons of water. 



In preparing the wash, the lime was started to slake with six gallons 

 of water, and while slaking, the sulphur , which had just previously been 

 made into a thin paste with hot water, was added and thoroughly mixed in 

 with the slaking lime. To prolong the boiling of the wash, the caustic soda 

 was then added with water as needed, and the whole mixture was kept thor- 

 oughly stirred. As soon as the chemical action had ceased the required 

 amount of water was added, when the mixture was ready to use. Aside from 

 the heating of the water, the cooking of the wash was done in a tub or barrel, 

 and took from ten to twelve minutes. In some preparations, especially when* 

 hot water was used to start the slaking of the lime, not all of the stated 

 amount of caustic soda was employed, but six pounds was the minimum. 



Dr. Felt, New York State Entomologist, writing under date of Oct. 30th 

 this year, advocates the employment of a lime-sulphur wash composed of 20 

 pounds of lime, 15 pounds of sulphur, and 40 gallons of water, bringing 

 about the combination either by using 10 or 12 pounds of sal soda and start- 

 ing the action by hot water in a barrel, or by boiling for at least 30 minutes. 



It will be noted that salt has not been used in the preparation of any of 

 these mixtures. In the preliminary experiments carried out three years ago 

 by Mr. G. E. Fisher, he came to the conclusion that the presence of the salt 

 added to the expense, made the wash more difficult to spray, and increased 

 its corrosive action on the metal parts of the pump ; while it failed to be 

 any more effective as a destroyer of scale, or more adhesive to the bark of the 

 tree. Whether these conclusions will be borne out by future experiments 

 remains to be seen, but some observations made this year show that probably 

 the presence of the salt is beneficial, and it would be advisable to conduct 

 experiments this coming season to test this very point. 



My observations this season would, I think, incline me to believe that 

 the presence of salt renders the wash more adhesive, and hence more effec- 

 tive. I found, as a rule, that in those orchards where the mixture adhered 

 longest and best to the bark the scale had made but little progress. 



It would appear that the adhesiveness of the wash is a large factor in its 

 effectiveness . The tremendous reproduction of the scale that occurs in Sep- 

 tember and October can hardly be checked, or the spread prevented, unless 

 the bark has a coating which is either distasteful or harmful to the crawling 

 larvae. For this very reason that the bark is made clean and enticing to the 

 larvae during the last months of the growing season, other remedies fail to 

 keep the scale in check, when only one application was made and that appli- 

 cation in the spring just before the buds opened. 



As to the results of the season's experiments with lime-sulphur, it may 

 be stated in a general way that little or no difference could be observed be- 

 tween the effectiveness of the cooked and uncooked washes. Some orchards 

 that had been treated with the cooked wash showed more scale at the end of 

 the season than at the beginning, and the same results were observed in 



