April, '09] JOURNAL OF ECONOMIC ENTOMOLOGY 145 



prematurely and as the trouble progresses the bark becomes mottled 

 and discolored with brown areas and the trees gradually die. In cases 

 where the ground water fluctuates through irrigation, the tree may 

 be growing in an apparently healthy and vigorous manner one day, 

 by the next the leaves may begin to show brown upon the edges, and in 

 a few days the entire foliage will look as if it had been sprayed with 

 some soluble arsenical solution. If the ground water remains close 

 to the surface for some time the bark will become mottled and the 

 trees will die. If it soon falls they will often drop their burned leaves 

 and. if not too late in the season, the young shoots will push out and 

 form a partial green covering again. This occurrence is so common in 

 some of the low lying districts adjacent to the Great Salt Lake, where 

 it is impossible to drain, that it occasions little comment, everyone 

 understanding the conditions that produce it. 



On the Central Utah Experiment Station an orchard was planted 

 just below an irrigated bench, or table land, and the seepage water 

 from the side of this bench rendered the upper end of the orchard al- 

 most impassable, and the trees gradually died. A trench was dug to 

 intercept this alkaline water, after which the ground below the trench 

 dried up, the remaining trees recovered and the orchard was appar- 

 ently saved. A year later a cave occurred in the trench and the 

 water began to rise again. Within a few days the trees in this area 

 w^ere brown and scorched, as if swept by a fire. The trench was then 

 cleaned and repaired, the water soon subsided in the orchard and all 

 the trees except one put forth a new crop of leaves. No arsenical 

 spray had ever been applied to this orchard until after the trees died. 



Conditions similar to this exist throughout the lower and heavier 

 land between Fruita and Palisade, Avhere not only the fruit trees have 

 died, as cited bj^ Doctor Headden, but a part of the farm land has 

 been mined by the alkali rising. Some of the orchards in this sec- 

 tion were badlj^ affected before they were sprayed and none of the 

 farm land has had any arsenicals applied at any time. 



Many other specific instances could be cited of orchards that have 

 been badly affected, or even entirely ruined, where no arsenical spray- 

 ing has ever been done, but it does not seem necessary. The above 

 facts seem to the writer to be sufficient to warrant the conclusion that 

 it is impossible to identify this condition with any effect of arsenical 

 sprays. 



"Collar Rot" Killing Trees 



The second condition described in the Colorado Bulletin is com- 

 monly recognized throughout the United States under the name of 

 ' ''collar rot," and apparently confines itself largely to the Ben Davis 



