1922 - Warren, D. C. Results of cotton dusting experiments for 1921, together with 

 summary of the dusting results of past three years. Ga. State Bd. Ent. B. 62, 

 9 p. Mar. Atlanta. 



The dusting experiments against the cotton boll weevil, carried out for the 

 past few years in Georgia, have shown that calcium arsenate dust gives the best 

 results. Where infestation is at all heavy, 2 applications, using 5 lbs. per acre, 

 should be made, with an interval of 3 or 4 days, just before the cotton squares 

 begin to form sufficiently for oviposition. Afterwards, the field should be exam- 

 ined closely, and where punctured squares appear, they should be picked off and 

 the plants dusted. If the infestation is spreading generally, dust should be applied 

 every 5 or 6 days, or 3 or 4 times at 4-day intervals. Dusting on damp, foggy 

 days gives better results than in dry weather. Dusting should be continued until 

 the bolls are matured at the top of the plant. Night or early in the morning is the 

 best time to dust. 



1922 - Warren, D. C. Relation of moisture to ingestion of poison by the cotton boll 



weevil. J. Econ. Ent. 15(5):345 -349. 



In view of the difference of opinion as to whether moisture is essential for 

 the cotton boll weevil to ingest poison, further experiments are here described. 

 In 1920, 72 hours after the poison (calcium arsenate) had been applied, there 

 was a mortality of 45% amongst weevils feeding when there was no dew, although 

 they remained on the poisoned plant a much shorter period than weevils feeding 

 when dew was present and there was a mortality of 35%. In 1921 the mortality of 

 the former was 85% for a period of 96 hours; 71% for the latter. From these re- 

 sults and those of other authors, it is clear that weevils are poisoned by ingestion 

 of poison with their food, rather than by drinking the poisoned dew. This conclu- 

 sion has nothing to do with the time of day when the poison is applied, as it is 

 established that better results are obtained from applying poison while the plant 

 is wet with dew. 



1923 - Ames, C t T. A progress report of boll weevil poisoning work at the Holly 



Springs Branch Experiment Station. Miss. Agr. Expt. Sta. C. 51, 11 p. Dec. 



As the result of experiments against the cotton boll weevil in Mississippi, 

 it was recommended that poisoning should begin just as the squares begin to 

 form. Where labor is plentiful, a mixture consisting of 1 lb. calcium arsenate 

 to 1 U.S. gal. treacle and 1 U.S. gal. water should be applied with a mop to the 

 top bud. Where labor is scarce, a dusting machine should apply calcium arsenate 

 dust in the bud. Earlier than this the poison would be useless. About 10 days 

 later, a second application of dust should be made by a machine. On hill lands 

 these 2 applications may be sufficient, but in valleys or lands where cotton grows 

 rank, if infestation reaches 10%, a third application of dust should be made. 



1923 - Barre, H. W. Boll weevil control. S.C. Agr. Expt. Sta. Rpt. 36:18-29, 4 fig. 

 Dec. 



Before the squares formed, applications of either a sweetened poison made 

 of calcium arsenate, treacle and water, or calcium arsenate dust, killed a large 

 percentage of weevils in the field; in some cases 80% to 98% of the weevils were 

 found dead 96 hours after the applications were made. The dry dust was more 

 effective when applied while dew was on the plants. In no case, however, were 

 weevils completely eliminated from fields by 3 or 4 applications of either liquid 

 or dry poison in June. 



The indications are that when initial infestation is reduced to a minimum by 

 means of these early applications, the time for mid-season and later applications 

 of dust will be delayed. Little increase in yield of cotton was produced by the 

 early applications alone. 



After the plants are large enough for blooming freely, the only means of 

 reducing infestation is by the use of a dust cloud of calcium arsenate applied with 

 a machine that thoroughly atomizes the dry dust and drives it down through the 

 cotton plant. Liquid poison, applied later in the season, seems to prevent rapid 

 increase but does not hold the weevil in check after the rains start in mid-July. 



