April. '08] JOURNAL OF ECONOMIC ENTOMOLOGY 113 



THE POSSIBILITY OF REDUCING BOLL WEEVIL 



DAMAGE BY AUTUMN SPRAYING OF COTTON 



FIELDS TO DESTROY THE FOLIAGE 



AND SQUARES 



By WiLMON Newell and T. C. Paulsen, Baton Rouge, La. 



The most important step in insuring a good crop of cotton in the 

 boll weevil infested region of the South is the early fall destruction 

 of the cotton plants in order to kill the immature stages of the weevil 

 contained in the squares and bolls, to destroy the food supply of 

 weevils already adult and to lengthen the period through which the 

 insects must survive until the appearance of the following year's crop. 

 So completely has this been demonstrated by the experiments of the 

 Bureau of Entomology in Texas, and more recently by Prof. W. D. 

 Hunter in an enormous field experiment in southern Texas, that 

 discussion of this point is entirely unnecessary. 



The great objection upon the part of planters to fall destruction 

 of the cotton plants is that the cotton crop cannot be picked out early 

 enough so that the plants can be uprooted and burned at the time 

 necessary to insure destruction of the greatest number of weevils, for 

 the labor problem in Texas and Louisiana is at present second in im- 

 portance only to the boll weevil problem itself. 



A method of practice which would destroy the weevils and their 

 food supply (leaves, squares and green bolls) early in autumn and at 

 the same time permit greater leisure for gathering the crop, has 

 long been recognized as a desideratum. The possibility of spraying 

 to destroy all green portions of the cotton plant, without affecting 

 thereby the lint in bolls still unopened, was discussed at length as 

 much as two years ago by Prof. W. D. Hunter and the senior author. 

 At that time we saw no possibility of the plan being practical. 



During the past summer the subject was again brought up by Dr. 

 T. J. Perkins, an extensive planter of Redfish, La. Doctor Perkins 

 had had experience in destroying the water hyacinth with sprays, and 

 being also a practical cotton planter, he believed that the same plan 

 could be made applicable in the warfare against the weevil. 



The writers accordingly decided to make a few experiments in a 

 small way to determine what could be accomplished along this line. 

 We first experimented with substances which we knew to be destruc- 

 tive to plant life, such as common salt, white arsenic, copper sulphate, 

 etc. 



Through the courtesy of Capt. J. F. Mclndoe, Corps of Engineers, 

 U. S. A., we were furnished with directions for preparing the mix- 

 ture of white arsenic and sodium carbonate used so successfully by 



