160 THE MEXICAN COTTON-BOLL WEEVIL. 



been uprooted. Therefore, every means should be taken at the time 

 of maximum infestation to plow under the infested squares as deeply 

 as possible. This method is of little use in dry regions, but fortunately 

 is of great importance in humid regions where other means of control 

 are comparatively lacking in efficiency. It is also assisted greatly 

 by the occurrence of large areas of so-called stiff soils in the humid 

 area. 



SUMMARY OF MEANS OF REPRESSION OF THE BOLL WEEVIL. 



In the preceding pages all effective methods of controlling the 

 boll weevil have been described in a general way, and their connec- 

 tion with the life history of the insect shown. Further details regard- 

 ing the application of the methods have been published in Farmers' 

 Bulletin 344. In the present connection it will be sufficient to sum- 

 marize the subject. The following are the essential features of the 

 control of the boll weevil: 



1. Prevention of the invasion of new territory by means of quarantines 

 directed against farm commodities that are likely to carry the weevil. 

 It is not necessary to have a quarantine applied to an extended list 

 of articles. Only a few forms of cotton and of cotton by-products 

 need to be considered. The most important is seed cotton. Next 

 in importance are cottonseed and cottonseed hulls. There is no 

 danger in cottonseed meal and scarcely any appreciable danger in 

 baled cotton. 



Cottonseed can be easily rendered entirely safe by fumigation with 

 carbon bisulphid, as described in this bulletin. 



2. The destruction of the weevils in the fall by uprooting and burning 

 or burying the plants. This is by far the most important step in con- 

 trol. (See PI. XX, a.) It is so important that unless it is followed 

 all other means will avail little to the planter. 



The burning of the cotton plants is, of course, a bad agricultural 

 practice. It should not be followed except in extreme emergencies. 

 In all other cases the plants should be uprooted as soon as the cotton 

 can be picked and cut by means of stalk choppers and immediately 

 plowed beneath the surface. The ground should afterwards be har- 

 rowed or dragged to make it still more difficult for the insects to 

 emerge. 



In many cases it will be found inadvisable to wait for the uprooting 

 of the plants until all of the cotton is picked. After only a small 

 portion remains for the pickers, it is entirely feasible to uproot the 

 plants by means of a turning plow and leave them in the field so that 

 the cotton can be picked. This will hasten the opening of the green 

 bolls and frequently result in a considerable saving to the planter. 



3. The destruction of the weevils during the winter. This is accom- 

 plished by the destruction of the places in which the insects hibernate. 

 Many such places are found in the cotton fields or in their immediate 

 vicinity. A certain number of the weevils will of course make their 

 way into the heavy woods and other situations beyond the reach of 

 of the planter, but many remain where they can be reached. 



4- Obtaining an early crop. (See PI. XXII.) The importance of 

 obtaining an early crop has been shown to depend upon the small 

 number of weevils which hibernate successfully, their late emergence 

 from hibernating quarters, and their comparatively slow development 



