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in. half of them by placing 10 eggs under the involucre, and leaving the 
other half with the natural infestation. The bolls were collected after 
10 days and examined for worms that had entered. In the field tests 
derris reduced the number of worms 23 percent on the stepped-up infestation 
and 4.9 percent on the neutral infestation. Of the 12 insecticides tried, 
only sodium fluosilicate (.26 percent reduction on; the stepped-up infestation) 
was better than derris. 
The effect of dusting bolls on cviposition was tried by placing 5 
pairs of moths in breeding cages with dusted and undusted bolls and deter- 
mining the. total number of eg<rs laid, and the percentage laid on the bolls. 
Moths in the derris c?gos became inactive and the average longevity 
was somewhat reduced. 
.Chapman, Kollingsworth and Robertson, in a typewritten report to 
the Chief of the Division. of Cotton Insect Investigations, stated that 
only slight reduction in the pink bollworm infestation; was effected in 
plants, heavily dusted with a mixture of cube and sulfur (l percent rotenone) 
at Eresidie, Tex.,, in 1935. Cube (5 percent rotenone) used as a spray, 
10 pounds to 50 gallons of water and 2 pounds of flour, reduced. the worm 
population 71.9 percent, as compared with 4-6.8 percent, from the use of 
barium fluosilicate -spray. Chapman and ^illiams; in a typewritten report 
in 1936- stated that a dust of 10 percent cube, 10 percent pyrethrum, and 
80 percent sulfur (0.4-9 percent rotenone), used in cage tests in 1936, 
was not so effective as barium fluosilicate or calcium arsenate. The 
weighted average percentage reduction in entries was 94.2.? for barium 
fluosilicate dust, 81 for calcium arsenate dust, and 76.21 for the cube r 
mixture dust. . 
The ..Texas Agricultural .Experiment Station ( L0/+ ) in 1936 and 1937 
reported the results of tests by Chapman and cthrs. Field tests wera 
conducted during 1934. using derris, one of the thre~ insecticides that 
showed most promise in 193^. Sulfur seemed slightly superior to either 
flour, kaolin, or tobacco dust as a diluent for derris. In 193/ tfce 
Texas Agricultural Experiment Station ( 405 ) reported on remedial measures 
conducted by Chapman as follows: Seasonal infextstion counts indicat 
that 'barium fluosilicate and cube-sulfur used separately ^s dusts or 
sprays reduced the worm population. This was more apparent on the plants 
dusted with barium fluosilicate. Further investigations are necessary 
to determine the merits of insecticides for the control of this insert. 
The United States Department of Agriculture, Bureau of Entomol< J 
and Plsnt Quarantine (^42) in 1936 reported that curium flusoilical 
cube, and cube-sulfur mixtures • r 1 .ct-.d for addition Id- 
plot tests. All gave some control, as indicted by a n duction of the 
the number of worms per boll, but none " -ry effective or satisfactory. 
Roark (357) in 1938 reviewed the 001 n <">f dermis ordi 
cube of equal rotenone content on many ins. etr. Be n ' rred to a 
typewritten report by Ch-praan and O.vitt, of the Division of Cotton Ineect 
Investigations, who, in 1934., made laboi on first in- 
