56 



have few or no living scale on them. In one orchard, although the 

 breeding season was already well advanced, there was only a single 

 tree upon which any larvae were found, but there were quite a number 

 of trees where living females occurred. The adjoining orchards 

 showed that the scale was in full progress of breeding. Wherever 

 very badly infested orchards were found it was obsei-ved that the wash 

 had been least effective; that is, it was not successful in killing any 

 large percentage of the scales. A tree incrusted with scales, still 

 coated with the spray, would, on examination, be found to contain 

 great numbers of the living insects underneaH;h. So where the mate- 

 rial was most needed it was least effective. On adjacent trees on which 

 the scales were scattering the effect of the wash was very good. The 

 wash does not penetrate nearly as well as the oil o*- soap mixture, 

 and it does not spread at all. Where it hits it sticks and seems effect- 

 ive, but it does not have much penetrating jHjwer. It is, furthermore, 

 difficult to get it on the smaller twigs. This is an important point 

 with apple trees, and unless the twig is hit the insects will not be 

 killed. 'Farmers generally agree that it takes 3 gallons of the lime- 

 sulphur-salt wash to do the work of 1 gallon of oil mixture. In New 

 Jersey a gallon of the wash was stated to cost for material about 1 J 

 cents. This did not include the cost of mixing and the incidental tost of 

 boiling and time of the laborer. In practice a sufficient amount of the 

 wash to go as far as 1 gallon of oil would cost 4i cents. One orchard- 

 ist used both, and prefers the oil because of its convenience. The 

 farmers in New Jersey used the undiluted oil more than the emulsion. 

 Some had tried to make a soap emulsion, but had lost all interest in 

 the mixture. He thought there was no doubt that, particularly in 

 peach orchards, the lime-sulphur-salt wash could be satisfactorily 

 used. The oil was hard on peach trees, unless sprayed on with a very 

 line nozzle, and very carefully. 



Mr. Marlatt said that he desired to join Dr. Smith in his hearty 

 appreciation of the value of the papers presented. The experiments 

 and work reported were of great interest on account of their consid- 

 erable extent. He believed that the results of the work reported by 

 Professor Scott and others in the South indicate that the question of 

 how to practically control the San Jose scale has been solved. He 

 congratulated the authors of the papers very heartily on the results 

 obtained by them. He refen-ed, in brief, to his personal experience 

 with the use of oil on trees, including the orange in California. 



In reference to the earh' experiments of the Department in the 

 East with the lime, sulphur, and salt wash, he stated that the work was 

 conducted by Mr. Coquillett and himself, and was carried out in the 

 most practical way, Mr. Coquillett having recently come from Califor- 

 nia, and being thoroughly familiar with methods there employed. A 

 careful record of weather conditions was kept subsequent to the treat- 



