1943 - Ewing, K. P., and C. R. Parencia, Jr. Dosages of insecticides to control the boll 

 weevil and the bollworm. J. Econ. Ent. 36(4) :607-6l0. 



Field-plot experiments were conducted at Waco, Tex., in 1942 to determine 

 the effectiveness of reduced dosages of calcium arsenate against the boll weevil 

 and whether cryolite could be substituted for calcium arsenate in its control. The 

 comparative effectiveness of calcium arsenate, basic copper arsenate, lead ar- 

 senate, and cryolite against the bollworm were also studied. The boll weevil in- 

 festation was too light to show any marked differences in yield between plots 

 treated with calcium arsenate, cryolite, and various dilutions of these materials 

 with sulfur, for weevil control. However, 1 experiment did show that 3 dilutions 

 of calcium arsenate reduced the weevil infestation to lower levels (average, 11.9%) 

 than did similar dilutions of cryolite (average, 13.9%). 



1943 - Gaines, J. C. Comparative tests of certain insecticides and variations in sched- 

 ules for cotton insect control. J. Econ. Ent. 36(l):79-8l. 



Alternate applications of calcium arsenate and lead arsenate, using 2 appli- 

 cations of lead arsenate during the period when bollworm injury was highest, 

 gave good control of both weevils and bollworms. When cryolite was substituted 

 for lead arsenate, losses in yields occurred because of increased weevil injury. 

 Two consecutive applications of either lead arsenate or cryolite at the peak of 

 bollworm injury, instead of calcium arsenate, did not prove to be effective against 

 the weevils, thus causing a loss in yield. 



1943 - Gaines, J. C., and H. A. Dean. The relative effectiveness of calcium arsenates 

 composed of large and of small particles. J. Econ. Ent. 36(l):76-78. 



A special calcium arsenate containing large particles, a special calcium 

 arsenate, sulfur, rotenone mixture, and commercial calcium arsenate were tested 

 against the boll weevil, bollworm, and aphids at College Station, Tex., and against 

 the boll weevil and aphids at Tallulah, La. Records were also kept on rapid plant 

 bug populations at both locations, but the populations were low, and only small dif- 

 ferences occurred between treatments. 



The special calcium arsenate and commercial calcium arsenate were equally 

 effective against weevils at both locations, but the coarse material (special cal- 

 cium arsenate) did not give as good control of bollworms at College Station as 

 the commercial calcium arsenate. Both materials contained approximately the 

 same percentage of water-soluble arsenic pentoxide. 



1943 - McGarr, R. L., and J. R. Henry. Insecticides tests for boll weevil and cotton 

 aphid control in the Mississippi delta. J. Econ. Ent. 36(5):7l6-7l8. 



An account is given of experiments carried out in 1942 on the control of 

 Anthonomus grandis Boh. and Aphis gossypii Glov., on cotton in Mississippi, in 

 which calcium arsenate and a mixture of calcium arsenate and sulphur (1:2) were 

 applied alone or with nicotine sulphate or other aphicides; approximately 5% 

 hydrated lime was added to the mixtures containing nicotine to insure its libera- 

 tion. The dusts were applied at the rate of 6 to 8 lbs. per acre at intervals of 4 or 

 5 days when boll weevil infestation exceeded 15%-25% in the plot showing the best 

 control, 4 to 6 applications being made between the middle of July and the middle 

 of August. 



Calcium arsenate with 2% actual nicotine in alternate applications and cal- 

 cium arsenate with 1% in all applications gave satisfactory control of the weevil, 

 kept the aphid infestation about the same as in untreated plots, and resulted in 

 increases in yield of seed cotton of 415 and 394 lbs. per acre, respectively, in 

 large-plot tests, and 323 and 318 lbs. per acre, respectively, in small plots, 

 whereas calcium arsenate alone controlled the weevil but resulted in a loss of 

 138 lbs. per acre in the large plots and a gain of only 11 lbs. in the small ones. 

 The yields for no treatment were 2,132 lbs. per acre in large plots and 1,912 in 

 small ones. The differences in yield between the treatments with and without 

 nicotine seemed to be largely due to aphid damage. In small-scale tests, calcium 

 arsenate alone gave better control of Anthonomus than the mixture of calcium 

 arsenate and sulphur, but resulted in the development of significantly more aphids, 

 in the absence of aphicides. 



37 



