29 



rosin solutions of which we give three formulas. The first was first tried 

 by Mr. A. Koebele; the second by Mr. Alexander Craw, of Los Angeles; the 

 third has been given me by Mr. L. D. Green, of Sacramento. From per- 

 sonal experiments with them all I am well satisfied with them. 



Recipe No. i.— Four jionnds of rosin, three pounds of sal soda, water to make thirty-six 

 pints. Dissolve the sal soda in a few pints of water; when thoroughly dissolved add the 

 rosin. Heat until dissolved, and add water finally. Use two quarts of solution to the 

 gallon of water. Use at a temperature of about 100 degrees Fahrenheit. 



Recipe No. 2.— One iwuncl of caustic soda, ten pounds of rosin, one hundred gallons of 

 water. Prepare as above. 



As, perhaps, owing to the nature of the caustic, the leaves are sometimes 

 liable to be affected, I should recommend the spraying of the trees with 

 pure water liberally (the water will free the pores of the leaves), then two or 

 three days after the applications of the rosin solutions. 



These solutions being cheap they may be used liberally, and two or three 

 treatments a year would, I think, keep the trees in fair order. 



Recipe No. S. — Sixty pounds of rosin, sixty pounds of tallow, ten pounds of potash, dis- 

 solved in ten gallons of water; ten pounds of caustic soda (Greenbank, 98 per cent). Dis- 

 solve the rosin and tallow; when dissolved add caustic water slowly. After mixture is 

 made, add ten gallons of water. Use at the rate of one gallon of mixture to ten gallons of 

 water. 



In the case of the black scale I have found the addition of sulphide of 

 soda at the rate of one gallon to seventy-five of rosin solution, the strength 

 of sulphide being one pound of concentrated lye to two pounds of sulphide, 

 beneficial, and I should recommend the trial of this for icerya. In several 

 orchards in Santa Barbara cold water has been sprayed on the trees with 

 great power, but while it must be considered superior to many of the inju- 

 rious ingredients used, it is only by its constant application that trees can be 

 kept clean. 



Banding of the Trunks. 



A most essential help in checking the icerya's spreading, whatever method 

 of cleaning is used, is the placing of bands on the trunks of the trees — say 

 six inches from the ground — which are usually strips of sheepskin, the 

 hairy side turned in and the smooth side out. The bands should be drawn 

 as tight as possible, and the outside covered with a mixture of molasses, or 

 printers' ink, or any substance that will remain sticky for some time. The 

 minute scale, which are constantly traveling through the summer time, will 

 be either caught in the sticky solution or find lodgment in the wood. From 

 time to time the bands nuist be taken oft' and dipped in scalding water, and 

 carefully replaced. The portion of the trunk below should be washed with 

 a strong rosin solution, three times as strong as any recommended above. 



Gas Remedies. 



In my last report to the State Board of Horticulture was given an account 

 of the various experiments made by difterent parties. In the recently pub- 

 lished report of Professor Riley, "United States Entomologist," Mr. Ooquil- 

 lett,of Los Angeles, gives an exhaustive account of experiments with various 

 gases, but I am of the opinion that none will supersede the hydrocyanic 

 gas, first used by Messrs. Craw, Wolfskill, and Coquillett, and later discov- 

 ered and recommended by F. W. Morse, of the University of California. 



The opinion then expressed, that no doubt applied, which would make 

 the application of the hydrocyanic gas void of danger, and cheapen the 

 process on the whole, I am glad to say, has been fulfilled, although my 



