i 52 THE MEXICAN COTTON-BOLL WEEVIL. 



time there seemed some hope that a machine designed to pick the 

 squares from the ground by suction might be perfected. The 

 experiments, however, have indicated probably insurmountable 

 difficulties; and a large implement concern, after having experimented 

 with the matter fully, has come to the conclusion that mechanical 

 difficulties will always prevent the perfection of such a machine. 



The ultimate test of all methods or devices for controlling the 

 weevil is to prove through a series of seasons, and under a large 

 variety of conditions, that by their use there is produced an increase 

 in the crop treated or protected of sufficient value to more than 

 repay the expenses of the treatment or protection. As a general 

 rule, where machines have been used or poisons applied, planters 

 have provided no check upon the results obtained and have kept no 

 close records as to the expense involved and net gain or loss resulting 

 from the treatment. The result of such applications is, therefore, 

 merely a general impression of gain or loss which may not agree 

 at all with the facts. 



In this connection it must be stated that all machines which 

 assist in more satisfactory methods of preparation of the land and 

 cultivation of the crop are of indirect advantage. This is especially 

 the case with devices which increase the amount of work that a single 

 hand or team of mules may do. In fact, the boll weevil has been the 

 cause of much commendable improvement of agricultural machinery 

 throughout the infested territory. 



GINNING MACHINERY. 1 



The more important results of studies upon this class of machinery 

 were presented in Farmers' Bulletin No. 209 of the Department of 

 Agriculture. Modern cleaner feeders were found to be quite efficient 

 in separating the weevils from the seed cotton, as they removed fulh 

 70 per cent of the weevils passing into them. Of the weevils removed, 

 over 80 per cent were still alive when taken from the trash. This 

 fact shows the necessity for the use of some additional device which 

 will crush or otherwise destroy all weevils taken from the cotton by 

 the cleaner feeder. (See PL X, a.) 



For the weevils escaping the action of the cleaner feeder and passing 

 into the ginning breast with the roll there are two avenues of escape — 

 one with the seed, the other with the motes. In these two ways it 

 appears that over 85 per cent of the weevils passing into the gin 

 breast escape alive, while the remainder are killed by the saws. 

 From these facts it is evident that some way should be provided for 

 properly caring for the motes so as to confine the weevils which are 

 thrown out among them and secure their destruction with those 

 removed by the cleaner feeder. Some method should also be 

 devised for separating from the seed the weevils that pass the saws 

 before they reach the seed house or the farmers' seed bins. 



When we consider the important effect that gins have been found 

 to possess in spreading the weevil, especially near the border line of 

 infestation, it appears exceedingly desirable that improvements in gin 

 machinery should l>o made in the following particulars: 



First. The area and distance through which the action of the picker 

 roll in the cleaner feeder is continued should be considerably increased, 



1 This section is modified from Bull. 51, Bureau of Entomology, pp. 158, 159. 



