68 



ports of experiments made in the Atlantic states. In articles pub- 

 lished in Bulletin 3 of the U. S. Division of Etotnolog-y, issued in 

 1806, and in Bulletin 30 of the same series, 1901, p. 34, the re- 

 ported failure of the California wash in the East is attributed to 

 the frequent occurrence of rains shortly after the insecticide had 

 been applied, and chemical testimony is broug-ht forward in sup- 

 port of this supposition. 



USE OF CALIFOKNIA AND OREGON WASHES IN 



irXINOIS. 



In the fall of 1901, when an appropriation of $15,000 for in- 

 secticide work on the San Jose scale became available to my office, 

 I was embarrassed by the fact that no effective insecticide pre- 

 viously used by us had been found free from serious liability to 

 injure the more tender fruit trees, or at least their fruiting^ buds. 

 The peach and the plum were especially liable to serious damag-e 

 by both the kerosone sprays and the whale-oil-soap solution, the 

 first being injurious to the tree, and the second very commonly de- 

 structive to the fruit buds and, of course, to the crop of the fol- 

 lowing- year. At this time I received from Professor Cordley, of Ore- 

 g-on, the above-mentioned letter, in which he suggested that I 

 should give the lime, sulphur, and salt compound a thorough test 

 in Illinois, and further said that in Oregon, where this mixture is 

 thoroughly effective, the climate is as moist during the winter — 

 when the spray is principally used — as in any part of the East. I 

 had additional testimony to the same effect from a former student 

 and assistant of mine, Mr. Fred McElfresh, who informed me, 

 after a year's experience in entomological work at the Oreg^on Agri- 

 cultural College, that the weather of western Oreg-on is very similar 

 to that of the greater part of Illinois. 



Under these conditions, I decided last fall to use the lime, salt, 

 and sulphur mixture, standard in the Pacific states, for all our Illi- 

 nois insecticide work on the peach and plum, preferring- to take 

 the risk of a possible inefficiency of the insecticide rather than the 

 much greater one of serious injury to the orchard tree. The sea- 

 son seemed favorable to the treatment, and highly encouraging- 

 reports came in from the field throughout the entire winter up to 

 early March. At this time, in order to secure more precise and 

 comprehensive information as to the value of the Oregon and Cali- 

 fornia washes, I detailed one of my office assistants, Mr. E. S. O. 

 Titus, to carry out a series of experiments with them under various 

 conditions and sent him to Summerfield, in St. Clair county, where 

 he remained for three weeks, supervising the treatment of the 



