calcium arsenate containing only 0.42% of water-soluble arsenic pentoxide caused 

 an average increase in yield over the checks of 239 lbs. of seed cotton per acre; 

 the one containing 11.4%, 220 lbs.; and the one containing 16.5%, 247 lbs. 



1941 - Jones, S. E. The effect on insect control on the yield and quality of cotton pre- 

 maturely killed by cotton root rot. Iowa State Coll. J. Sci„, l6(l):82-84. 



An account of investigations carried out in Texas in 1937-39, which showed 

 that the low yield of cotton, from plants killed by root rot before the first normal 

 picking, was not materially increased by controlling infestation by Psallus 

 seriatus Reut., and Anthonomus grandis Boh. Control of the Capsid was effected 

 by dusting with sulphur, and the weevil, with calcium arsenate. If, however, yield 

 from the surviving plants in an affected field is sufficient for profitable cotton 

 production and insects are damaging the crop, control measures should be ap- 

 plied against them. 



1941 - McGarr, R. L,. Cryolite and cryolite- sulfur mixtures for boll weevil control and 

 their effect on the cotton aphid. J. Econ. Ent. 34(4):500-501 . 



A cryolite- sulfur mixture containing 29.7% of sodium fluoaluminate gave no 

 control of the boll weevil, and one containing 34.6% of sodium fluoaluminate, very 

 little control. Cryolite alone was about half as effective as calcium arsenate. 



1941 - McGarr, R„ L. Control of the cotton aphid and the boll weevil in 1940. J. Econ. 

 Ent. 34(4):580-582. 



In tests conducted at State College, Miss., in 1940, calcium arsenate and 

 mixtures of calcium arsenate and sulfur for boll weevil control caused significant 

 increases in cotton aphids. The addition of derris to these materials effectively 

 controlled the aphids and held the populations at nearly the same level as the 

 checks. There was practically no difference in aphid control from derris when 

 mixed with regular calcium arsenate, derris mixed with micronized calcium ar- 

 senate, or derris and calcium arsenate mixed and then micronized. Nicotine and 

 tobacco dust, when added to calcium arsenate, were not effective in preventing an 

 increase of aphids. 



Calcium arsenate and calcium arsenate- sulfur mixtures with derris gave 

 good control of the boll weevil. There was no significant difference between these 

 treatments and undiluted calcium arsenate under the conditions of this experiment 

 where the weevil infestation was light. 



1941 - Moreland, R. W„, E„ E„ Ivy, and K. P. Ewing. Insecticide tests on the bollworm, 

 boll weevil, and cotton leaf worm in 1940. J. Econ. Ent. 34(4):508-51 1. 



In cage tests at Waco, Tex., in 1940, various insecticides and mixtures of 

 insecticides as dusts were compared with calcium arsenate against the bollworm, 

 Heliothis armigera (Hbn.), boll weevil, Anthonomus grandis Boh., and cotton leaf 

 worm, Alabama argillacea (Hbn.). 



When bollworm larvae were arranged into 4 weight groups, with one excep- 

 tion, mortalities due to insecticides varied inversely with the weight of the larvae. 

 A mixture of basic copper arsenate and lime killed approximately the same per- 

 centage of large worms (over 45 milligrams) as calcium arsenate killed of small 

 worms (under 15 milligrams). Against bollworm larvae of all weight groups, the 

 average mortality, after 120 hours, was 91.8% from the basic copper arsenate and 

 lime mixture, 87.9% from lead arsenate, 83.7% from undiluted basic copper ar- 

 senate, 82.7% from cryolite containing 66.1% of sodium fluoaluminate, and 62.3% 

 from calcium arsenate. 



Basic copper arsenate and mixtures of this material with lime and with sul- 

 fur gave somewhat higher kills of the boll weevil and the leaf worm than did cal- 

 cium arsenate. 



1941 - Rainwater, C. F„, and Floyd F, Bondy. Combinations of insecticides for control 

 of boll weevil and cotton leaf aphid. J. Econ. Ent. 34(2):297-300. 



Experiments were conducted on 2 Latin squares consisting of 36 0.05-acre 

 plots, each, and on 4 0.75-acre field plots near Florence, South Carolina, during 

 1939 to determine the relative effectiveness of several insecticides and combina- 

 tions of insecticides for control of the boll weevil and the cotton leaf aphid. 



32 



