Calcium arsenate, mixtures of equal parts of calcium arsenate and two 

 fixed-nicotine dusts, and barium fluosilicate plus derris (to give a rotenone con- 

 tent of 0.5%) were significantly better than 2 of the 3 cryolites tested with or 

 without the addition of derris for boll weevil control, when based on average 

 seasonal infestation. Yield records and boll counts did not show significant dif- 

 ferences between treatments. 



The cryolites and barium fluosilicate with derris were inferior to calcium 

 arsenate in dusting qualities but were followed by aphid populations of only 12% to 

 24% of those treated with calcium arsenate. 



Equal parts of calcium arsenate and fixed-nicotine dusts held the aphid popu- 

 lation to approximately 50% of that in the undiluted calcium arsenate treatments. 

 Equal parts of calcium arsenate and sulfur, or of calcium arsenate and diatoma- 

 ceous earth, with the addition of derris, gave satisfactory boll weevil control and 

 kept the aphid population equal to or below that of the checks. 



1941 - Rainwater, C. F., and Floyd F. Bondy. Boll weevil and cotton aphid control by the 

 use of derris in combination with calcium arsenate. J. Econ. Ent. 34(6):733-735. 



In identical experiments conducted at Florence, S.C., State College, Miss., 

 Tallulah, La., and Waco, Tex., in 1940, 4 insecticides or combinations of insecti- 

 cides were tested against the boll weevil and the cotton aphid, Aphis gossypii 

 Glov. They were calcium arsenate, with and without derris, at the rate of 6 lbs. 

 per acre per application and equal parts of calcium arsenate and sulfur, with and 

 without derris, at the rate of 12 lbs. per acre per application. Eight effective 

 applications were made at each location. 



Analysis of the data showed that there was no significant difference in the 

 degree of boll weevil control between any 2 insecticides and that each was sig- 

 nificantly better than the check. Counts of aphid populations showed highly sig- 

 nificant differences favoring the insecticides which contained derris over those 

 which did not. Yield records showed that calcium arsenate plus derris was 

 significantly better than calcium arsenate alone. 



1941 - Smith, G. L., A. L. Scales, and R. C. Gaines. Further studies of various insecti- 



cides against three cotton insects. J. Econ. Ent. 34(2) :310-3 1 3. 



In cage tests conducted at Tallulah, La., in 1939, several arsenicals and 

 cryolites were used against the boll weevil and the cotton leafworm, and derris, 

 pyrethrum, sulfur, and calcium arsenate-sulfur mixtures against the tarnished 

 plant bug. 



With calcium arsenates that had been separated into fractions according to 

 particle size, definite correlations were shown between particle size and per- 

 centage of water-soluble arsenic pentoxide as determined by the New York 

 method, between particle size and net boll weevil mortality, and between per- 

 centage of water-soluble arsenic pentoxide and net mortality. 



Calcium arsenate was more effective against the boll weevil and the cotton 

 leaf worm than cryolite with or without wetting agents. Dicalcium arsenate gave 

 better results than commercial calcium arsenates, calcium arsenate-sulfur mix- 

 tures, or basic copper arsenate. The addition of wetting agents to calcium arsen- 

 ate and to cryolite did not significantly affect mortality. Calcium carbonate and 

 sulfur appeared to be better carriers for calcium arsenate than lime. 



1942 - Baerg, W. J., and D. Isely. Insect investigations at the Arkansas station. Ark. 



Agr. Expt. Sta. B. 428:36-41, 52-53. 



Contains notes on spot dusting to control the boll weevil. 



1942 - Becnel, I. J., and E. H. Floyd. Insecticide tests for cotton aphid and boll weevil 

 control during 1941. J. Econ. Ent. 35(5):623-626. 



To study the effect of Aphis gossypii Glov. on the yield of seed cotton, in a 

 program for the control of the boll weevil, and to determine the effectiveness of 

 several aphicides in combination with calcium arsenate, experiments were car- 

 ried out in 1941 in 2 localities in Louisiana. 



33 



