49 



Crude caustic potash.— CvuAq caustic potash in solution was used at 

 strengths of 1, 2, and 3 pounds to 10 gallons of water. The first appli- 

 cation (made in the fall) was of the medium strength, with results far 

 from successful, owing perhaps to wet weather immediately following. 

 The second spraying, March 6, gave the following results as shown 

 by examination made May 6: 



1 pound to 10 gallons, 25 per cent of scale alive. 



2 pounds to 10 gallons, 3 per cent of scale alive. 



3 pounds to 10 gallons, less than 1 per cent of scale alive. 



No injury to the trees resulted, but the stronger solutions cut the 

 hose very badly. It is cleai-, then, that potash used strong enough will 

 successfully destroy the scale, but it is quite impractical to use it 

 extensively at the required strength owing to its caustic effect upon 

 both the hose and the operators. 



Eesin wash — One application prepared according to the standard 

 formula was followed by no good results. 



Carbolic acid emulsions. — Three different washes, of unknown com- 

 position, but consisting essentially of an emulsion of crude carbolic 

 acid with varying proportions of oils, soap, and other ingredients, were 

 given thorough trials. It was found that less than a 16 per cent 

 strength of any of these washes was practically ineffective, and though 

 20 and 25 per cent strengths were reasonably effective, the cost would 

 debar their use. 



PKACTICAL WOEK IN A LARGE OECHAED. 



In addition to the regular experiments, an orchard of 55,000 three- 

 year-old peach and 1,000 plum trees belonging to Mr. W. C. Wright, 

 of Fort Valley, Ga. , was treated under the writer's supervision. Mr. 

 Wright was very much alarmed over the condition of his orchard, and 

 he made a special request of the entomologist to assume full control 

 of its treatment. 



Beginning August 8, 1901, the orchard was given an inspection row 

 by row, which revealed 1,000 badly infested trees well distributed. 

 From these centers of infestation the scale had spread generally in all 

 directions, leaving only a small percentage of the trees entirely free. 

 Beginning August 20, all the badly infested trees that had been located 

 were sprayed with a 10 per cent strength of kei'osene, using a knap- 

 sack "kero-water" pump. This checked the breeding of the scale, 

 and was apparently the means of saving a large number of trees that 

 would doubtless have perished before time for winter treatment. 



From December 26 to January 2 each badly infested tree and with 

 15 or 20 adjacent trees were sprayed with a 15 per cent strength of 

 kerosene, using a barrel pump. In this manner the 1,000 trees repre- 

 senting the centers of infestation had received two applications of oil 

 7796— xN'o. 37—02 ± 



