36 



Aloes. — Dr. M. F. Bishop, of Alameda, the owner of a large orchard 

 of deciduous fruit trees in the vicinity of San Jose, in the northern 

 part of the State, gave me a package of aloes, with the request to test, 

 it on the scale insects infesting citrus trees. Accordingly I made a 

 few tests with it, simply dissolving the aloes in cold water, straining 

 the solution through a piece of Swiss muslin, and then spraying it 

 upon the tree. The aloes is not readily soluble in cold water, and 4 

 days were required for it to dissolve, being occasionally stirred during 

 this time. The experiments are as follows : 



(243) Aloes, 12| pounds ; water, 100 gallons. Sprayed on an orange 

 tree infested with the yellow scale (Aspidiotus citrinus) at 10:30 a. m., 

 March 22, sun shining, light breeze. April 23, leaves and fruit unin- 

 jured ; found many living yellow scales on this tree. 



(242) Aloes, 25 pounds ; water, 100 gallons. Sprayed on an orange 

 tree at 10 a. m., March 22, sun shining, light breeze. April 23, leaves 

 and fruit uninjured; found several living yellow scales both on the 

 leaves and fruit of this tree. 



The price of the aloes in large quantities is at the rate of 16 cents 

 per pound; at this rate the strongest solution I used (experiment 242) 

 would cost $4 per 100 gallons. At this strength (25 pounds of aloes to 

 100 gallons water) it proved fatal to a large percentage of the scale 

 insects, and doubtless if it had been used one-half stronger it would 

 have been entirely effectual ; but the high price of a solution of the 

 latter strength would prevent its being used on a large scale. 



