THE BOLL WEEVIL PROBLEM. 41 
cotton plant. At this time it is possible to destroy a considerable per- 
centage by the application of poison. Exhaustive experiments per- 
formed by the Bureau of Entomology and other agencies demon- 
strated that Paris green can not be used to advantage at this time. 
More recent work with powdered arsenate of lead by Mr. Wilmon 
Newell, formerly of the Louisiana State Crop Pest Commission, seems 
to show that this poison can be used to advantage when the plants are 
small and the weevils abundant. Experiments performed in Louisi- 
ana in 1909 showed that cotton treated with powdered arsenate of 
lead yielded an average of 71 per cent more than similar cotton which 
was not treated. For two vears the Bureau of Entomology has been 
experimenting with this poison. In many cases its use has resulted 
in increased yields more than sufficient to offset the cost of the appli- 
cation. In other cases there has been a loss. It is evident that under 
some circumstances the poison can be used with profit by the planter. 
Experimental field work now under way in Louisiana is expected to 
show the exact practical application of this poison in the control of 
the boll weevil. 
Sweetened poisons—Many attempts have been made to cause 
poisoned substances to be attractive to the weevil by introducing 
sweets and other ingredients. All these have failed completely. Some 
known sweets, such as honey, have a slight attraction for the weevil, 
but net enough to assist in practical control even regardless of their 
expense. 
Contact poisons.—Poisons designed to kill the weevil by suffocating 
rather than by being taken into the digestive organs have been pro- 
posed. They can not, ef course, be effective against the immature 
weevils within the cotton fruit. The difficulties in reaching the adults 
are in their manner of work. Normally these insects are found inside 
the bracts of the squares, where they can not be reached by sprays. 
Tn fact, nature designed the bracts to prevent the heaviest rains from 
reaching the square within. An additional difficulty is in the expense 
of applying sprays, not only on account of labor, but on account of 
the special machinery that is necessary. Although there is some very 
remote possibility that dry poisons may be found of assistance in con- 
trolling the weevil, on account of the facts mentioned it is not at all 
probable that liquid sprays can ever be used. 
Effect of confinement.—There is one peculiarity of the weevil that 
has led to many unwarranted claims as to the efficacy of remedies. 
The insect wili die within a very short time when confined in a bottle 
or jar or even in a cage. Even when cages are placed over growing 
plants it is found that numbers of the insects die and fall to the 
ground, though no poison has been applied. In many instances ex- 
perimenters have appiied thei: preparations under such conditions 
and have found dead weevils later. They have made no allowance 
512 
