Report of State Board of Horticulture. 7 



to do is to pour your ai'senate into the water and stir well. Its ad- 

 vantages over other forms of arsenic are as follows: 



First. It remains in suspension longer than any other arsenical 

 spray, and hence requires but little agitation. 



Second. It is very adhesive, but little affected by rains, and therefore 

 requires a less number of applications. 



Third. It is more pleasant to handle, and can be used any strength' 

 without injury to foliage. 



The arsenate of lead has been highly endorsed by the University of 

 California, Professor Steadman, entomologist of the State of Missouri, 

 Professor Gillette of Colorado, and many other authorities. In Coloi-ado 

 but three sprayings were used, with excellent results. Professor Stead- 

 man recommends four: first, when petals fall; second, two weeks later; 

 third, thirty days after the second; and, fourth, thirty days still later. 

 If used with bordeau, the Massachusetts Station reccommends using 

 only one-thii'd of the arsenate. 



The Merrimac Chemical Company, of Boston, send out a paste form 

 of arsenate of lead known as Swift's Arsenate of Lead; and the Bowker 

 Insecticide Company, of New York, a similar preparation known as 

 Disparene, and both have given excellent results. It might be better 

 to use one of these when only a small amount is required, and two and 

 one-half pounds of either will be sufficient for fifty gallons of water, 

 in which they dissolve readily. They sell for about 15 cents per pound 

 in 100-pound kegs. 



If you want to make your own arsenate, you should see that the 

 arsenate of soda contains about 47.8 arsenic acid, and the acetate of 

 lead about 58.8 available lead oxid. , 



In a bulletin of the University of California the wholesale price of the 

 lead is quoted at IVz cents, and the soda arsenate at 5 cents per pound. 

 I have been unable to get quotations anywhere near these prices in 

 Oregon, but inquiries will be extended. I suggest that your local drjg- 

 gist will probably be pleased to supply you. 



Yours truly, E. L. Smith. 



The San Jose scale is in importance the second dreaded foe 

 of the orchardist. The females of this pernicious insect can 

 not fly, yet they are remarkable travelers. Coming from 

 Central China, they made their way to the seaboard, crossed 

 the broad Pacific, colonized the Pacific Coast country, cros3ed 

 the Rockies, and made themselves at home in the Mississippi 

 Valley, extended their travels to the Atlantic Coast where they 

 multiplied incredibly, and may we not presume that some of 

 their progeny are on a visit to their original habitat in 

 China, having in a few years belted the globe. The San Jose 

 scale can never be exterminated by artificial means, as it is 



