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th e first berries, because, where a long bearing season obtains, the treatment 
with an arsenical poison after this period may result in harmful residues on 
the ripened berries. In preliminary tests, both derris and pyrethrum powder, 
applied as dusts, have shown promising results in controlling this insect. 
TOBACCO INSECTS 
Although tobacco is not a food, it would appear that arsenical or other 
poisonous residues on tobacco leaves may be harmful or undesirable to the con- 
sumer, and therefore v prec uticn should be taken to keep residues resulting 
from the use of insecticides on tobacco at a minimum. For this reason, lead 
arsenate is no longer recommended for use on tobacco. 
Tobacco hornworms 
A fairly satisfactory remedy for tobacco hornworms consists of a mixture 
of paris green 1 part and slaked lime 6 parts. This dust should be applied with 
a hand-operated crank duster for small acreages and a small traction duster for 
farms growing as much as 20 acres of tobacco, at the rate of 7 to 8 pounds per 
acre, per application, the rate depending upon the size and type of tobacco. 
Especial care should be observed in the manipulation of the crank duster in 
order to obtain a satisfactory coverage, while at the same time keeping the 
rate of application as low as possible. The dust gun nozzle should be held in 
the center of the space between the tobacco rows and not aimed directly at the 
foliage. This precaution is essential to avoid placing heavy deposits of paris 
green on certain leaves, which would cause serious burning. 
Tobacco grown under shade cloth in Florida and Connecticut is protected 
to a large degree from hornworm attack by the cloth walls and tops of the shade 
structure. Efforts should be made to keep the cloth intact throughout the 
growing season. The 1 to 6 mixture of paris green and lime may be used if 
applied with care. The rate of application should be about 4 pounds of the 
mixture per acre for each treatment. 
Fall and winter plowing, by which process the overwintering pupae are 
destroyed, is an effective cultural control for reducing the population of 
hornworms in tobacco. Hand picking of the worms, where the acreage is limited, 
can be practiced to advantage, especially with low-priced labor. 
Flea beetles 
The most satisfactory control for flea beetles attacking tobacco is a 
derris or cube dust containing 1 percent of rotenone. These dusts are obtained 
by diluting derris or cube powder to the desired strength with a clay diluent. 
The following dosages of dust are recommended for each application: 
For plant beds, \ pound per 100 square yards, applications to be re- 
peated every 4 days until control is obtained. For newly set plants, 
3 to 5 pounds per acre, applications to be repeated every 4 days until 
control is obtained. For the growing tobacco crop, 6 to 10 pounds per 
acre, depending upon the size of the plants, applications to be repeated 
every 7 days until control is obtained. 
