34 BULLETIN 124, U. S. DEPARTMENT OP AGRICULTURE. 



tically controlled the pest in the last few years, and they have 

 accomplished it altogether by such methods as have just been de- 

 scribed. One of these men, Mr. Henry Stroven, whose ranch is 

 north of Holtville, says that he has had a minimum of damage. 

 His ranch evidences his careful and systematic cultural methods. 

 Ditch banks and fence rows are clean, and there is scarcely a 

 weed noticeable on the entire ranch. Mr. Stroven informed the 

 writer that he always renovates twice a year and sometimes oftener 

 and also aims to keep his alfalfa abundantly watered in order to 

 get a quick, thrifty growth. The other rancher, Mr. William Mans- 

 field, of Brawley, practices the same methods in use by Mr. Stroven, 

 and his ranch also shows this. Neither of these ranchers aims to 

 allow his alfalfa to stand longer than five years in a certain field. 

 Instead, he plows it up, raises some other crop for a year, and then 

 reseeds to alfalfa, thus bringing into play a system of crop rotation 

 which not only keeps the soil in excellent condition, but prevents 

 insect increase. Mr. Mansfield told the writer that in 1908 he had 

 considerable damage when his May cutting was getting a little more 

 than two-thirds grown. One day he noticed that damage from the 

 caterpillar was very apparent. The next day the effect was much 

 more noticeable. So he mowed the alfalfa, taking it up at once, and 

 irrigating as soon as possible. He thus saved by far the greater part 

 of the crop infested and, besides, was not troubled again that year. 



The following observations, made by Mr. R. N. Wilson in July, 

 1913, also bear out the foregoing statements: 



One farm was examined near Meloland, CaL, to-day. This is a dairy farm 

 belonging to Mr. Cook. In order that the hay may be in the best condition, 

 Mr. Cook cuts it jnst as it comes into bloom. He in this way gets two more 

 cuttings of hay per year than his neighbors, who allow their fields to come to full 

 bloom before cutting. His crops have never been badly injured by Eurymus, 

 while his neighbors have more or less injury every year. He also keeps his 

 alfalfa in a thrifty condition, and the rapid growth is another element in 

 Eurymus control. 



These three examples show the practicability and the success of 

 the methods proven by observation and experimentation to be means 

 of controlling outbreaks of the alfalfa caterpillar. 



EXPERIMENTS AND OBSERVATIONS IN ARIZONA. 



Observations similar to those in California were made in Arizona 

 by the author in 1912 and in 1913 by Mr. T. Scott Wilson. The same 

 relation has been noted to exist between clean culture and good farm- 

 ing methods in general and damage by the alfalfa caterpillar as 

 existed in California. But in Arizona, as the soil conditions are 

 somewhat different from those in California, it is necessary for the 

 application of water to be even more timely. In many parts of the 



