224 FUMIGATION METHODS 



lance in causing all Flprida trees to be disinfected by 

 both dipping and gas treatment. The red scale of 

 Florida, Aspidiotus ficus, has been introduced on im- 

 ported trees, but was without doubt eradicated by the 

 gas treatment that the trees received. ' This is over the 

 signature of F. Edward Gray, at that time one of the 

 Horticultural Commissioners of L,os Angeles County, 

 'California. In June, 1891, a shipment of 325,000 

 oranges arrived at the Port of San Pedro from Tahiti, 

 and were fumigated with hydrocyanic acid gas. 



' * During the above years the county commissioners 

 in Southern California demanded certificates that nur- 

 sery stock had been fumigated or dipped. Dr. L. O. 

 Ho ward's history of fumigation, as printed in the 'Year- 

 Book for 1899, United States Department of Agricul- 

 ture,' is not correct. I notice on page 151 of that re- 

 port that he considers, in 1894, ne was the fi rst to 

 recommend fumigation of nursery stock before delivery 

 to purchasers. I know that previous to 1894, as cited 

 above, that hundreds of thousands of nursery trees had 

 been fumigated in California before being delivered 

 to purchasers. The fact of the matter is the United 

 States Department of Agriculture had practically noth- 

 ing to do with the discovery of the gas treatment, as 

 Mr. Coquillett was not then in the employ of the 

 Department." 



Fumigate greenhouses regularly. I fumigate my 

 greenhouses and cold frames about four or five times a 

 year with it, and have thus been able to keep down all 

 insect and animal pests except the red spider. How- 

 ever, about 80 per cent, of the red spiders are killed 

 by the regular treatment recommended, but to com- 



