Comparison of the results from treatment with calcium arsenate or calcium 

 arsenate and nicotine with results from no treatment or treatment with nicotine, 

 only, showed that the arsenate caused significant reductions in weevil infestation 

 in all localities, increases in number of aphids in all localities except in Louisi- 

 ana, and increases in yield in all but Florida and Louisiana. The increase in yield 

 in Texas was partly due to the control of the bollworm. Calcium arsenate gave 

 significant increases in yield (391%, 64%, and 45%, respectively) over the control 

 plots in South Carolina and Louisiana, where weevil infestation was heavy, and 

 Texas, where it was intermediate. Nicotine gave nonsignificant increases in 

 Florida, Louisiana, and Texas; and calcium arsenate and nicotine together gave 

 significant increases of 418%, 128%, and 41%, respectively, in South Carolina, 

 Louisiana, and Texas. 



1942 - Roark, R. C. Insecticides for control of cotton insects. Chem. Engin. News 

 20:1169-1172. 



Contains a list of the principal insects that attack the cotton plant in the 

 United States and of the insecticides mainly used for their control, with the esti- 

 mated annual consumption of each. Calcium arsenate is used chiefly for the con- 

 trol of the boll weevil, which is the most destructive pest and is estimated to 

 destroy an average of 10% of the crop, but it is also recommended against the 

 cotton leafworm and the bollworm. The chemical and physical composition of 

 commercial and other calcium arsenates are discussed in some detail, with the 

 rates at which they should be used and the methods of application. 



Fluorine seems to be the most promising substitute for arsenic in insecti- 

 cides. Reviewed are the results obtained in tests of insecticides with a special 

 light sodium fluosilicate and a special calcium arsenate with a low arsenic con- 

 tent. Cryolite was shown to be effective against H. armigera but only half as toxic 

 to Anthonomus as calcium arsenate. Ordinary calcium arsenate diluted with an 

 equal weight of hydrated lime is effective against light infestations of the weevil. 

 Paris green, when mixed with half its weight of calcium arsenate, is also of value 

 against Anthonomus . 



All these insecticides, with the exception of sulphur, are likely to become 

 scarce in the United States, owing to war conditions; it is important that they 

 should be applied as effectively and economically as possible. 



1942 - Robinson, J. M., and E. L. Mayton. Yield in cotton due to control of boll weevil. 

 Ala. Agr. Expt. Sta. 1941 Rpt. 52:27-32. 



The results of experiments in 1924-41 in which the gain in yield of cotton, 

 due to the control of boll weevil by dusting with calcium arsenate in years in 

 which the amount of infestation required it, increased with the amount of ferti- 

 lizer applied to the plots. 



1942 - Smith, G. L„, A. L. Scales, and J. A. Fontenot. Effect of insecticidal drift in 

 small plots upon boll weevil and cotton aphid. J. Econ. Ent. 35(4):594-595. 



Mortalities in the first row of the checks adjacent to treated plots were, 

 in most cases, higher than in the third and fifth rows. Check plots having a 

 treated plot adjacent on 2 sides had an average weevil mortality of 22.7% and 

 20.3%, as compared with average mortalities of 35.1% and 33.8% in check plots 

 having treated plots on all sides. In the laboratory yard where the check cages 

 were not near treated plants, the average mortality was only 17%. 



The average mortality was 79.6% in 2 plots treated with the standard cal- 

 cium arsenate, 67.6% in 2 plots treated with a mixture of standard calcium ar- 

 senate and derris, and 50.3% in 2 plots treated with a special calcium arsenate. 

 In the laboratory yard average cage mortalities for the 3 treatments were 86%, 

 84%, and 85%, respectively. 



1942 - Thomas, F. L., Clay Lyle, F. S. Arant, and Dwight Isely. Report of the commit- 

 tee on cotton boll weevil control, Proc. 7th Ann. Meet, of Cotton States Br., Amer. 

 Assoc. Econ. Ent. J. Econ. Ent. 35(2):297. 



In view of the evidence by research agencies, confirmed by practice in rep- 

 resentative sections of the country, the membership of the Cotton States Ento- 

 mologists reaffirm their confidence in the established methods of boll weevil control. 



35 



