THE USE OF PAKIS GREEN IN CONTROLLING THE 

 COTTON BOLL WEEVIL. 



INTRODUCTION. 



During the past season there has been a very extensive use of Paris 

 green in an attempt to control the boll weevil in Texas. This has 

 been due to several mistaken conceptions about the habits of the pest, 

 as well as man}' misconstructions of the results of applications made 

 in the field by various parties. It has been known for many years 

 that it is possible to destroy a certain number of boll weevils by the 

 use of Paris green, provided applications are made early in the season 

 before an}^ squares are set upon the plants. At this time the weevil 

 feeds on the opening leaflets, and heavy applications of poison destroy 

 a number of them. Many persons have thus killed a certain number 

 of weevils and have concluded that the number found feeding upon 

 the 5'oung plants having no squares represents the total number of 

 weevils in the field. As a matter of fact, however, abundant observa- 

 tions have proven that a very great majority of weevils do not come 

 from hibernating quarters until after the plants have begun to put on 

 squares. This is shown in Table VI on a following page. After 

 squares are formed upon the plants the weevils no longer feed upon 

 the leaves, but puncture the squares, and are then beyond the reach 

 of poison. It will be seen from the foregoing statements that early 

 in the season a few weevils may be killed by the use of Paris green, 

 and it is from this fact that the idea has taken hold of many farmers 

 in Texas that in this poison the}' have a specific against the pest. 



On account of the ver}' great attention which has been called to the 

 proposed method of controlling the boll weevil by means of Paris 

 green the Department of Agriculture has devoted special attention 

 to the matter. Experiments have been performed at different points 

 in Texas upon the experimental farms of the Bureau of Entomology, 

 in which care was taken to eliminate all disturbing factors and to 

 obtain accurate information regarding the possibility of poisoning the 

 weevil. In addition to this work, agents connected with this Bureau 

 have visited practically all of the fields at which, at one time or another 

 during the season, the owners have supposed that satisfactory results 

 have been procured. The Bureau of Entomology has from time to 

 time during the season warned the planters through the press against 



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