A.O.A.C. method, and free Ca(OH)2. The effectiveness of both calcium arsenate 

 and lead arsenate seems to vary inversely with the amount of carrier added. 

 Calcium arsenate showed significantly higher net mortalities of boll weevils and 

 cotton leaf worms than the 4 cryolites that were tested. There appeared to be a 

 definite relation between net mortality and the amount of cryolite (Na3AlF) in the 

 various samples of cryolite. In general, treatments with highest percentages of 

 toxicant caused the highest net mortalities of boll weevils and leaf worms, though 

 none was effective. 



1939 - Anonymous. Later than customary poisoning of boll weevils indicated as profit- 

 able in cotton production. Miss. Farm Res. 2(10):7. 



Straight calcium arsenate gave better control of the boll weevil and cotton 

 leaf worm than a mixture of half calcium arsenate and half hydrated lime. 



Studies indicate that growers can wait until plants are large and fruiting 

 heavily and punctures reach 10% to 25% before dusting is necessary. 



1939 - Bondy, F. F. Early versus late poisoning and a combination of both for boll 

 weevil control. J. Econ. Ent. 32(6):789-792. 



Since dusting with calcium arsenate for the control of Anthonomus grandis 

 Boh. on cotton is followed by injury on sandy types of soil and the occurrence of 

 aphids in large numbers after several successive applications, efforts were made 

 to overcome these disadvantages by reducing the quantity of the arsenical used. 

 Previous experiments indicate that, under conditions of light damage, satisfactory 

 and economical control could be obtained in South Carolina by using diluted cal- 

 cium arsenate. In 1938 the value of diluted calcium arsenate and pre- square 

 treatments (directed against weevils coming out of hibernation) was tested under 

 conditions of moderately heavy damage. 



Presquare applications to the terminal buds, made 3 times at intervals of 5 

 days, resulted in no appreciable increase in yield and were expensive, whether 

 they were of undiluted calcium arsenate dusts and equal quantities of calcium ar- 

 senate and hydrated lime, or of mixtures applied with a mop--l lb. of calcium 

 arsenate and 1 gal. of water, with or without 1 gal. of molasses. Presquare ap- 

 plications of calcium arsenate and hydrated lime, or the molasses mixture, fol- 

 lowed by 3 of calcium arsenate and hydrated lime, when the squares were large 

 enough for oviposition, increased the yields only slightly, with negligible profit 

 and at a high cost. The presquare molasses treatment increased the yield con- 

 siderably, with comparatively high profits and low costs, when followed, after 

 10% of the squares were infested, by several dust applications of calcium arsen- 

 ate or by equal quantities of the arsenate mixed with hydrated lime, sulphur, or 

 calcium carbonate. In general, the late dust treatments, alone, gave the highest 

 yields and profits at the lowest cost. 



Undiluted calcium arsenate, applied when 10% of the squares were infested 

 gave the best results throughout. On light sandy soils, however, where there is 

 danger of soil injury, the presquare molasses treatment followed by late dusting 

 with calcium arsenate and hydrated lime, which gave the next best average profit 

 per acre, is recommended. Presquare treatments delay the date when 10% of the 

 squares become infested, reduce the number of later dust applications, and, 

 hence, reduce the danger of soil injury and of building up harmful infestations of 

 aphids. The best late treatment, when there is danger of soil injury and no pre- 

 square treatments have been given, is the dust of calcium arsenate and lime, 

 which had the lowest cost per 100-lb. increase of yield. The dust containing sul- 

 phur is advisable when the flea hopper ( Psallus seriatus Reut.), tarnished plant 

 bug (Lygus pratensis L.) or red spider ( Tetranychus telarius L.) is abundant. 



1939 - Gaines, R. C. Boll weevil control tests with calcium arsenates containing dif- 

 ferent percentages of water-soluble arsenic pentoxide. J. Econ. Ent. 32(6):794- 

 797. 



In cage and laboratory tests net boll weevil mortalities caused by intermedi- 

 ate (4.5% water soluble arsenic pentoxide) and high (10.5%) calcium arsenate did 

 not differ significantly, but both differed significantly from the low (0.4%). In 



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