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UNITED STATES DEPARTMENT OF AGRICULTURE 
Washington, D.C. 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Vv 
July 20, 1920 
COTTON BOLL WEEVIL CONTROL BY THE USE 
OF POISON.* 
By B. R. Coan, Eniomological Assistant, and T. P. Cassipy, Cotton Hntomolo- 
gist, Southern Field Crop Insect Investigations. 
Principles governing poisoning op- 
eration 
Kind of poison to use_-______--__ 
Poison specifications required___- 
Send samples of calcium arse 
nate for analysis 
Use of mixtures 
not recom- 
Supply of calcium arsenate and 
dusting machinery available_ 
Keeping qualities of calcium ar- 
senate 
Effect. of the poison on man and 
animals 
Plant injury by calcium arse 
nate 
How: to apply poison=—"- = ==_-—= 
Amount required per acre for 
eacheapplication==—=. 
Conditions under which to make 
applications 
Arrangement of poisoning sched- 
ule 
Season for applications________ 
Time of starting poisoning____ 
Time interval between applica- 
tions 
Number of applications 
Time to stop poisoning_______~_ 
CONTENTS. 
Page. | 
How to apply poison—Continued. 
1 Effect of rain on an application 
3 Of} POISON: See ee ee 
3 Starting poisoning in the pres- 
ence of a complete infestation_ 
4 Harlier season treatment of 
isolated infestations________ 
4 | Organization of poisoning operation_ 
Dusting machinery to use_______-_ 
4 Handgouns 22: | an aes See 
Powendusters== see eee 
5 Wheel-traction or cart dusters- 
Need of an intermediate type of 
5 dusting machines. 
Lighting equipment for dusting 
G Machines Sse Laue ee 
8 Capacity of machines for treat- 
ing several rows per trip____ 
Features to be noted in purchasing 
8 cotton-dusting machinery__-__-~_~- 
ER ary GS Ws ee ee 
9 Wheel-traction or cart duster__ 
Power duster.) 222 eee 
OE aCOSE Of poisOnin sys a ae ee ee 
10 | Gains to be expected from poisoning_. 
11 | Advisability of poisoning under 
present conditions —-_—~____-____ 
12 | Control of the cotton leafworm and 
14 fall army worm with calcium 
14 arsenate: (fcltoabe te Se Se ee 
PRINCIPLES GOVERNING POISONING OPERATION. 
T SHOULD BE UNDERSTOOD that in poisoning for boll- 
weevil control extermination is not attempted or secured. The 
result aimed at is a sufficient reduction of the weevil infestation to 
permit maturing a full crop of cotton. This is brought about by tak- 
Page. 
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1The investigations upon which this bulletin is based were in a sense the outgrowth 
of the work of Mr. Wilmon Newell, who puodlished, together with Mr. G. D. Smith, in 
174542°—Bul. 875—20——_1 
