472 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



occurs the water should be first softened by means of caustic potash 

 fish oil soap. This soap has been found to be satisfactory for this 

 purpose by adding four or five pounds to each 125 gallon tank of hard 

 water. There are, however, a number of oil emulsions which contain 

 the proper stabilizers, incorporated in their manufacture, which prevent 

 oil from separating when combined with "hard" waters, thus doing 

 away with the expense of initially softening the water. 



Recommendations 



Barring some of the difficulties which may be experienced with the 

 use of paraffine oil emulsions, they have proven the most satisfactory 

 and efficient. The trees are cleansed thoroughly of sooty mold through 

 their use. The writer has found that a paraffine oil emulsion applied in 

 December at a strength of one gallon of stock solution to seventy gallons 

 of water followed by another in March at a strength of one gallon of 

 stock solution to eighty gallons of water, gave good results toward 

 controlling the scales on the mango. A great deal depends upon the 

 thoroughness with which the sprays are applied. 



ARIZONA WILD COTTON OR THURBERIA AND ITS INSECT 



ENEMIES IN RELATION TO THE COTTON INDUSTRY 



OF THE SOUTHWEST 



By A. W. Morrill, Ph. D., Consulting Entomologist, Los Angeles, Cal. 



The recent appearance of the Arizona wild cotton or Thiirberia boll 

 weevil^ in several cultivated cotton fields near Tucson, Arizona and the 

 uncertainties in regard to the extent of the infestation, also the un- 

 certainties in regard to the probable infestation of cultivated cotton in 

 the Southwest by the Thurberia bollworm- constitute a serious menace 

 to the cotton industry of the Southwest, and at the same time serve as 

 an object lesson in the handling of complicated insect problems. A 

 review of the facts in regard to the situation referred to will place on 

 record a statement of entomological principles involved in the wild 

 cotton problem and tend to prevent further meddling by politicians with 

 matters involving grave dangers to agricultural industries and which 

 properly belong to the field of economic entomology. 



That the Thurberia weevil is evidently better adapted to the climatic 

 conditions of the arid and semi-arid southwest and consequently a more 

 serious menace to cultivated cotton in that region than the eastern 



^Anthonotnus grandis thurberiae Pierce -Thiirbeiiphaga calalin a Dyar 



