• . BUEEAU OP ENTOMOLOGY. 503 



ton boll weevil, (2) tobacco insects, (3) sugar-cane insects, (4) rice 

 insects, (5) the Argentine ant, (6) the cotton red spider, (7) cactus 

 insects, (8) ticks. 



The work was conducted under the direction of Mr. W. D. Hunter, 

 whose headquarters were at Dallas Tex., and branch stations were 

 located at Sabinal, Tex. ; Crowley, La. ; New Orleans, La. ; Tallulah, 

 La. ; Clarksville, Tenn. ; Appomattox, Va. ; and Batesburg, S. C. 



THE COTTON BOLL WEEVIL. 



During the year the cotton boll weevil extended its range into the 

 State of Alabama. The season as a whole, however, was again very 

 abnormal as regards weevil damage. On account of the peculiar 

 conditions of the preceding summer and winter, as pointed out in the 

 last report, a very small number of weevils issued from hibernation 

 in the spring of 1910, and unprecedented drought from the start 

 prevented the normal increase in the number of weevils in the field. 

 In August so great was the effect of these checks that the weevil had 

 done no noticeable damage to the crop in Oklahoma, and the same is 

 true for a large area in northern and western Texas. Central 

 Louisiana, southwestern Mississippi, and the river bottoms of the 

 coastal region of Texas suffered more seriously than any other part 

 of the infested region. There was a smaller increase in infested 

 territory during the year than in any year since 1903. 



The most important line of work undertaken at the Delta labora- 

 tory at Tallulah, La., was the testing of the possibility of the use of 

 powdered arsenate of lead or other poisons in the control of the 

 weevil. This work was suggested by the apparently favorable out- 

 come of earlier experiments by the Louisiana Crop Pest Commission. 

 The results of the year's experiments were largely contradictory and 

 inconclusive. The abnormal conditions of the season and the unu- 

 sually small number of weevils present were partly the cause of this. 

 Apparently successful results were obtained in certain plats, while 

 others on the same plantation failed to show any profit from the use 

 of poison. 



It has been found that in many quarters there are serious objections 

 to the burning of the cotton plants in the fall. In regions where cot- 

 ton has been cultivated for many years and the soil has been robbed 

 of its humus, this objection is especially strong. The one best remedy 

 for the weevil is the destruction of the plants in the autumn, and 

 burning has been recommended by the bureau, but some plan less 

 open to objection from a broad agricultural standpoint must be de- 

 vised. Therefore every form or method of the burial of plants which 

 could be practiced upon the plantation has been tried and compared 

 against the burning of the plants at the same time. If the plants 

 could be killed while standing in the autumn, an important advance 

 would be gained, since it would prevent the production of the fall 

 broods of the weevil, which are the ones which pass through the 

 winter in the greatest numbers. An important difficulty in the 

 method of fall destruction now practiced is that the labor available 

 is frequently insufficient to pick the crop by the time the plants 

 should be uprooted^ whereas if a method of killing the plants while 

 they are still standing could be devised it would be possible to con- 

 tinue picking the staple all through the winter. Tests have been 

 made of various chemical means of killing the plants with this end 



