50 
BULLETIN 746, U. S. DEPARTMENT OF AGRICULTURE. 
On a plantation scale, however, such a treatment, even in a modi- 
fied form, would be impossible. Experiments have shown that treat- 
ment of cane cuttings on a plantation already infested with the moth 
borer and the mealybug has little or no effect in reducing the sub- 
sequent infestation. In the season of 1911-12, a very great effort was 
made to eliminate sugar-cane insects from a small property in Loui- 
siana. The trash on the fields was burned in the fall, the entire farm 
was given over to plant cane, no cane was windrowed, all cane was 
planted in the fall after having been dipped in a fish-oil soap solu- 
tion (to kill the mealybugs) , nearly all the stubble was removed from 
the fields (according to the plans all the stubble was to be removed, 
but the work was so difficult and expensive that some of the stubbie 
was plowed under to a depth of 1 or 5 inches) , and, finally, the plant- 
ing of corn was delayed in the spring of 1912 so that any possible 
hibernated moths of the borer would not find corn as an early food 
plant. While the work may not have been done in an absolutely 
ideal way, the experiment was much more thorough than ordinarily 
would have been possible. 
Even the weather seemed to cooperate to render the experiment a 
success. The winter of 1911-12 was cold, and the cane was late in 
sprouting in the spring, so that it seemed that there was no cane dur- 
ing the winter to serve as a food plant for the borers. Small borers 
were found, however, as early as May 21, 1912, and by October IT 
the infestation ran as high as 75 per cent, with an average of 59 per 
cent. As to the mealybug, practically all the plants were infested. 
The experiment was evidently entirely negative in its results. 
More exact experiments have been conducted to indicate the actual 
effect of fumigation and immersion on both the insects and the sugar- 
cane cuttings. Table VIII gives the results of dipping cuttings in 
various insecticides and fungicides and also of soaking the cuttings 
in the solutions for one hour, the borers afterwards being cut out to 
ascertain whether they were yet alive. The borers were kept and fed 
for about two weeks after the treatments. 
Table VIII. — Effect on moth-borer larvw of immersion of infested cane cuttings. 
Solution. 
Expo- 
sure. 
Num- 
ber of 
lar- 
vae. 
Condition of larvae im- 
mediately after treat- 
ment. 
Penetration of solution 
in cane cutting. 
Condition 
of larva? 
two weeks 
after treat- 
ment. 
Dip... 
Ihour. 
Dip... 
Ihour. 
9 
6 
9 
11 
All alive 
Penetrated, and was 
deposited on sides of 
holes. 
Some of the stalks were 
evidently full of the 
solution. 
Evidently penetrated 
the stalks. 
do 
do 
All dead. 
Fish-oil soap, \ pound 
per gallon water. 
do 
All alive, 4 had emerged 
from cane and were in 
the solution. 
8 alive. 
9 alive. 
