54 BULLETIN 746, XT. S. DEPARTMENT' OF AGRICULTURE. 
and from cane depositing their eggs on the young corn plants as 
well as on the cane. 
BURNING CANE TRASH. 
Iii the process of harvesting sugar cane the tops of the plants 
and the lateral leaves are cut off and left in the fields, forming a 
quantity of fibrous vegetable matter almost universally called " the 
trash." (PL VIII, fig. 1.) A common recommendation has been 
to burn this debris as soon as it is dry enough, which is within a 
few weeks after the cane has been cut. Apparently burning would 
tend to decrease the subsequent infestation by the moth borer, but 
this has not been found to be the case. Examinations of the trash 
indicate that comparatively few borers are usually to be found in 
it, most of them being in the stalks of the cane, which are carted 
from the field and ground in the mill, thus disposing of the greater 
number. On the other hand, the trash is a favorable hibernating 
place for numbers of dipterous and hymenopterous insects, many 
probably of beneficial species. The eggs of the moth borer are de- 
posited on the leaves of the cane plants, and these are attacked by the 
egg parasite Triclxo gramma minutum. It is probable that these 
minute beneficial insects are destroyed in great numbers when the 
trash is burned. 
Louisiana sugar-cane planters have been burning over their sugar- 
cane fields for many years (PL IX, fig. 2), and it has not been found 
that any reduction in the number of canes infested by the moth borer 
results. Trash burning and other methods of control formerly recom- 
mended were thoroughly tried out on a plantation in Louisiana some 
years ago (see " Immersion and fumigation of infested seed cane," p. 
49), but without beneficial effect. It is the opinion of the authors, 
after having made many field observations, that trash burning can 
not be expected to diminish the number of canes infested, while it 
ma}^ increase the infestation by destroying beneficial insects. An 
objection to trash burning, admitted even by its advocates, is that 
ordinarily it is not thoroughly done. The dry leaves which burn 
readily are consumed, and in the fields are left short scraps of cane, 
which sometimes contain living borers, even though they have been 
considerably heated and charred by the fire. It is evident that trash 
burning, while unquestionably destroying many beneficial insects, 
frequently fails to destroy the few borers left in the field, because of 
their protected situation in scraps of cane which do not burn readily. 
When it is remembered that there are four or five generations of 
borers per year, that about half of the adults are females, and that 
each female lays an average of 200 eggs, it will be realized that a 
very few borers passing the winter successfully are sufficient to infest 
a whole plantation, especially if their parasites have been destroyed. 
