8 



placing too much dependence upon poison, but despite these warnings 

 it is estimated conservatively that at least 25 carloads of Paris green 

 have been used in Texas. The rather complete results of the work 

 that has been conducted by the Bureau of Entomology are presented 

 in the following pages. As a result of all that has been done b}^ the 

 Department, as well as the conclusion from careful examinations of 

 many cotton fields in Texas, the Bureau of Entomolog}^ does not 

 recommend the use of Paris green in an attempt to control the boll 

 weevil. 



The fact that applications of Paris green will kill a certain per cent 

 of weevils upon treated plants has been known to the agents of the 

 Bureau of Entomology for ten years. Its use through the medium 

 of a spray was suggested as early as 1895 (Circular No. 0, new series) 

 and repeated in 1897 (Circular No. 18, new series; Farmers' Bulletin 

 No. 1:7) and in 1898 (Circular No. 33, new series). It was, however, 

 recommended then only as a means of killing off some of the hiber- 

 nated weevils before squares appeared on the cotton. 



Through the repeated experiences of several seasons it had been 

 found that spraying cotton with a solution of Paris green had no pos- 

 itive value in controlling the boll weevil throughout the season, and 

 this conclusion has been generally accepted as well established. 

 Therefore the work of the agents of the Bureau of Entomology with 

 Paris green during the season of 1901 has been confined mainly to the 

 application of the poison as a dry powder. Many claims have been 

 made for the superiority of this method of using the poison and for 

 its efficacy, when so used, as a remedy for the Mexican cotton boll 

 weevil. Early in the spring of 1901 a comprehensive series of tests 

 was begun upon areas sufficientlj'^ small to allow ever\^ plant to be 

 thoroughly prepared, treated, and examined, so that as far as is pos- 

 sible in the field every weevil might be accounted for and the exact 

 effect of the poison determined under the varying conditions of the 

 test made. 



Upon more extended areas the Bureau of Entomology has this year 

 conducted field tests extending through the season. Checks were 

 kept in these field tests and the results of the poisoning must be judged 

 by a comparison of the crop records of poisoned and check areas, 

 which in all other respects were intended to be under similar condi- 

 tions and to receive identical treatment. In addition to the field 

 results, determined by agents of this Bureau, the experience of a 

 number of representative, practical planters has been drawn upon. 



Whatever results might have been obtained upon small areas, it is 

 evident that only results of actual field practice in various localities and 

 by a number of men could ever demonstrate the advisability of adopting 

 or rejecting the use of dry Paris green in the fight against the weevil. 



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