ECONOMIC VAUJE OF FUMIGATION 229 



methods for the destruction of scale pests. The in- 

 creased cost of fumigation over spraying has, however, 

 induced some orchardists in Southern California to 

 resort to the cheaper method of spraying. Fumiga- 

 tion is the only remedy considered at all effective for 

 the red scale. The amount of cyanide required to 

 destroy black scale, if done at the proper time, is about 

 one-half that required for red scale. In addition to 

 my duties as Horticultural Commissioner, I am also 

 Superintendent of Fumigation. I have been connected 

 with the horticultural commission of Riverside County 

 for the past six and a half years. R. P. CUNDIFF. 



Arizona. In July, 1900, I employed this treat- 

 ment for the destruction of the date palm scale, Parla- 

 toria viflrix, imported with a large consignment of 

 some four hundred date-palm suckers from Algeria. 

 We subjected the suckers to fumigations varying from 

 0.3 to 0.5 per cent. gas. The foliage of the plants, 

 being of exceptionally hard and impervious nature, 

 was not injured. Prof. R. H. FORBES, Director Ari- 

 zona Experiment Station. 



Arkansas. I am convinced that the treatment 

 with hydrocyanic acid gas is an excellent method and 

 destined to become of general service. I have been 

 recommending it to nurserymen on occasion, though 

 entirely on the basis of knowledge derived from the 

 reports of others, such as your own. Prof. KRNEST 

 WALKER, Entomologist Arkansas Experiment Station. 



Fumigation operations in Canada. The following 

 report was furnished the writer by Prof. William 

 L,ochhead, of the Ontario Agriculture College : In 



