TOBACCO HORNWORM INSECTICIDE : 



RECOMMENDATIONS FOR USE OF POWDERED ARSENATE OF LEAD 

 IN DARK-TOBACCO DISTRICT. 



Page 



Advantages in the use of arsenate of lead 



Some early tests of arsenate of lead in com- 

 parison with Paris green 



Comparison of results obtamed by use of Paris 

 green and arsenate of lead in 1916 in Ken- 

 tucky and Tennessee 



CONTENTS. 



Page. 



D osage of arsenate o i lead required 8 



How to apply arsenate of lead to tobacco 9 



When to apply arsenate of lead 9 



Grade of arsenate of lead that should be used . 9 



Cost of arsenate of lead 10 



Summary 10 



TOBACCO HORN WORMS 1 are the everpresent and most serious 

 pests of tobacco in Tennessee and Kentucky. Without con- 

 trol measures no tobacco could be grown. When labor was 

 cheap and plentiful, hand-worming as a means of control was 

 fairly satisfactory, but with the increasing scarcity, cost, and 

 inefficiency of hand labor this method had to be abandoned and 

 the tobacco growers were forced to use an insecticide or cut 

 down the acreage. About 20 years ago, when insecticides were 

 first employed, Paris green was found to be the safest and most 

 efficient. Nevertheless, there has always been serious objection to 

 its use on account of the very frequent serious burning of tobacco, 

 which reduced the value of the crop frequently as much as 5 per cent 

 and occasionally by as much as from 10 to 25 per cent. To find a 

 safe and efficient insecticide has been one of the main lines of inves- 

 tigation at one of the field laboratories of the United States Bureau 

 of Entomology in Tennessee. As a result of the present investiga- 

 tion the dij^lumbic form of arsenate of lead was found to meet aU 

 requirements. 



During the last tliree years tobacco growers in the "Black Patch" 

 have used many tons of arsenate of lead upon tobacco, and from the 

 reports of satisfaction received it is very evident that its use will be 

 increased during 1917; accordingly, for the benefit of those who will 

 use arsenate of lead for the first time, as weU as for those who have 

 begun its use recently, it has been thought advisable to set forth a 

 comparison of results obtained by farmers in 1916 with both Paris 

 green and arsenate of lead with the results obtained by agents of the 

 bureau from arsenate of lead experiments, that tobacco growei-s may 

 know, from actual records, what to expect in foUowing the biu*eau 

 recommendations. 



1 Phlegethontius sexta Joh. and P. quinquemaculala Haw.; order Lepidoptera, family Sphingida;. 

 Note.— This bulletin supersedes Farmers' Bulletin 595. 



354°— 17 3 



