occur in the majority of fields until August 19 or later. The average increase in 

 yields of seed cotton resulting from the use of calcium arsenate dust on com- 

 parable plots was 236 lbs. per acre. The average expense of using the calcium 

 arsenate dust method was the cost of 29.27 lbs. of calcium arsenate and 3.6 

 hours of labor. 



1924 - Smith, G. D. Further experiments with the Florida method of boll weevil con- 

 trol. Fla. State Plant Bd. Q. B. 8(2):27-72, 9 fig. Jan. Gainesville. 



During 1923 further experiments were made with the Florida Method of 

 control for the cotton boll weevil, particularly with regard to weather conditions 

 and with a view to finding a method that would give quicker mortality. 



1924 - Smith, C. M., and S. B. Hendricks. The determination of free calcium hydroxide 



in commercial calcium arsenate. Indus, and Engin. Chem. l6(9):950-95 1. Sept. 

 Wash. 



A method that has been devised for estimating the quantity of free lime pres- 

 ent in calcium arsenate, as used for controlof the cotton boll weevil, is described 

 in detail. 



The results, shown in tables, give the quantity of calcium hydroxide present, 

 with an average error of about 0.02%. The results obtained from commercial 

 samples were practically as satisfactory as those obtained when mixtures made 

 from pure compounds were used. This method does not work so smoothly in the 

 presence of magnesium compounds, and as commercial calcium arsenate some- 

 times contain a sufficient amount of them to affect the results, it is hoped to 

 modify the method to include products containing them. 



1925 - Anonymous. Insect pests. Tenn. Agr. Expt. Sta. 1924 Rpt. 37:27-31, 9 fig. 



Knoxville. 



The Mexican bean beetle and the cotton boll "weevil are the two most serious 

 insect pests in Tennessee; the use of sodium fluosilicate and hydrated lime (1:9 

 by volume) for dusting against them has already been noticed. 



1925 - Armstrong, G. M., R. W. Moreland, and R. C. Gaines. Progress report on 



studies on boll weevil control under South Carolina conditions. S.C. Agr. Expt. 

 Sta. B. 223, 64 p., 25 fig. June. 



Calcium arsenate dust, applied after 10% of the squares were found to be 

 punctured by the weevil, resulted in 2.6 times the increase of seed cotton that 

 was produced by the Florida Method, 3.1 times that with 1 pre -square applica- 

 tion of molasses mixture, 1.6 times that with molasses mixture applied with mop 

 and sprayer, and 2.2 times that with molasses mixture applied with a mop 

 throughout the season. Early applications of molasses mixture and early appli- 

 cations of calcium arsenate dust, both of which were followed by calcium arsenate 

 dust after 10% infestation, induced practically the same increase of seed cotton 

 as calcium arsenate dust applied after 10% infestation. One pre -square applica- 

 tion of molasses mixture, followed by calcium arsenate dust after 10% infesta- 

 tion, produced 2.2 times the gain of seed cotton that was made with 1 pre-square 

 application of calcium arsenate dust alone. Molasses mixture applied with both 

 mop and sprayer and nicotine dust made practically the same increase of seed 

 cotton. 



1925 - Grossman, E. F. A preliminary report on how the cotton boll weevil takes up 

 poison. J. Econ. Ent. 18(1):236. 



The cotton boll weevil receives the poison accidentally on the tip of the 

 proboscis, and later, when chewing or moving its mandibles, the poison is in- 

 troduced into the intestine. Sprays are less efficient than dusts because as the 

 spray dries it forms a varnish-like film of poison, which does not adhere to the 

 proboscis of the weevil crawling over the poisoned area, whereas loose particles 

 of dust do so readily. 



12 



