37 



arsenious oxid. These results are considered as showing the extent 

 to which arsenic is removed when the plants are not harvested until 

 some time has elapsed after spraying. It is further pointed out that 

 applications of Paris green shortly before harvesting should be 

 avoided. 



' ' While the question * * * is still open to discussion * * * 

 it may be confidently asserted that the amount of arsenic contained in 

 the small fraction of a pound which a man would consume in a day, 

 eA*en if taken at one dose instead of being distributed throughout 

 twelve hours, would produce no harmful effect." 



INSECTS AFFECTING TOBACCO. 



Most of the common insect pests which are troublesome to tobacco 

 culture have been studied by the stations. The Kentucky Station has 

 given attention to the prevention of depredations by the tobacco worm, 

 the bud worm, the ilea beetle, the spined tobacco bug, and grasshop- 

 pers. The spined tobacco bug, 1 which causes the plants to wilt sud- 

 denly and thus checks their growth, was noticed to attack tobacco 

 plants grown next to a pasture, whence the bugs are believed to have 

 come. As a remedy, removing the bugs from the wilted plants is sug- 

 gested, and as a preventive measure, not to allow weeds, especially 

 thistles and mullein, which are very attractive to these insects, to grow 

 near tobacco fields is recommended. 



It was also observed that when corn becomes inedible to the corn 

 worm this insect attacks tobacco grown in adjoining fields. To obviate 

 this trouble it is advised not to grow early corn near tobacco. 



It was further noticed that grasshoppers" 2 sometimes do damage to 

 tobacco when grass or other close-growing crops upon which they have 

 fed are removed. The use of Paris green was found to destroy them, 

 but not before some damage had been done. The author suggests that 

 all unnecessary growth likely to harbor these pests near the fields 

 should be kept down. 



Several specimens of bud worms were studied. 3 They left the 

 tobacco plants and went into the ground August 10, and the adult 

 moths came out about two weeks later. It was observed that the speci- 

 mens under observation gnawed holes in the young leaves at the center 

 of the plant before they were unfolded. A thorough application of 

 Paris green is considered a suitable remedy. 



For the flea beetle, dusting with pyrethrum or spraying with a solu- 

 tion of this powder is regarded as* preferable to the use of lime water, 

 which deteriorates the quality of the leaves by the deposition of lime. 



For the prevention of damage by the tobacco worm,* the ordinary 

 practice of putting sirup poisoned with cobalt, arsenic, or strychnine 



1 Kentucky Station Bui. No. 66. 2 Ibid. No. 63. 3 Ibid. No. 49. 4 Ibid. No. 40. 



