METHODS OF CONTROLLING TOBACCO INSECTS. 



13 



a carrier, but the writer prefers to mix it with twice its weight of 

 finely powdered air-slaked lime, for when the application is made 

 without a carrier the cloud of dust from the nozzle of the dust gun 

 is so thin that it is impossible to determine whether the application is 

 being made evenly. On the other hand, if the Paris green is mixed 

 with about twice its weight of lime, the cloud of dust from the nozzle 

 will always show whether the gun is working properly, and a clogging 

 of the tubes can be discerned instantly. Apply tht dust early in tin 

 morning when the dew is upon the plants and when there in no breezt . 



Fig, 10.— Applying Paris green to tobacco with a dust gun. (Original.) 



Use a dust gun that has a strong fan power, and apply to only one 

 row at a time. Great care should be taken to make the application 

 even and thorough. No definite date can be given for making the 

 fust application. The time will depend upon the appearance of the 

 young tobacco worms, and it may be the last week in .Inly or not 

 until about the middle of August. In 1908 and 1909 some of the 

 early planted tobacco at Clarksville, Tenn., did not require poisoning, 

 and in 1909 some of it required almost no worming. The first appli- 



