4 o8 
Journal of Agricultural Research 
Vol. XXIV, No. s 
the main stem of the plant, working from the top downward. In such 
cases the injury closely resembles cutworm work. Only the first- 
generation larvae work on com, and then usually only when it is very 
small. 
In sod the injury is not so characteristic. The larva merely lives in 
its silk-lined tube, cuts off one blade of grass at a time, and draws it 
down into the burrow, where it is consumed at leisure. It is doubtful 
if the larvae leave their burrows in the daytime, but they will feed during 
the day, as can be seen by the motion and gradual disappearance of a 
grass blade inserted into the burrow. All excrement is packed into the 
I6wer end of the burrow or sometimes into side pockets forking from 
the main burrow. When one burrow becomes too small, or is filled with 
the bright green sawdustlike frass, it is abandoned and another con¬ 
structed. Occasionally a burrow is found as a silken tube running back 
under a board or stone lying on the surface of the ground. 
Felt (5, p, 69-^4) and other writers have described and figured definite 
cylindrical nests made by crambid larvse, but these have been observed 
by the present writer in only one instance, and that in connection with 
this species. In this case numbers of larvae were confined in lantern- 
globe cages with small potted sods of blue grass. They had reached 
about the fifth instar in late September, and at once constructed tubular 
nests of bits of dry grass blades tightly fastened together and smoothly 
lined with silk. They were suspended among the leaves of the blue- 
grass plants, some of them partly in the ground and some entirely above 
and clear of the ground. (Pi. i, A.) They contained no excrement and 
were closed at the bottom, but open at the top. The larvae seemed to 
make no effort to close them and wintered successfully in them, although 
exposed to every change of'temperature in an open outdoor insectary. 
After the construction of these nests the larvae fed no more until the 
following spring. It seems probable that such nests are constructed 
only when the soil is excessively wet, in order that the larva may remain 
dry during the cold weather. Excessive moisture and dryness are both 
enemies of larvae overwintering in cages, and it is difficult to provide 
exactly proper conditions for them. From these and other observations 
it may be concluded that in Tennessee the larvae construct and enter 
their winter quarters about the last of September. They begin feeding 
again in April, and the first moths make their appearance about the 
middle of May. 
Two series of 10 larvae each were run at different times to obtain 
records of the amount of food eaten. Blue-grass leaves cut into 30- 
millimeter lengths were used for food. At the close of each instar the 
uneaten portion was removed and measured. Since the larvae skeletonize 
the leaves during the first three instars of their life and the total amount 
consumed during that time is insignificant, these instars are omitted 
from the record. The figures represent linear millimeters of blue-grass 
leaves of an average width of about 3 millimeters. The results of the 
two series were so similar that they are combined in Table IV. 
As indicated by this somewhat incomplete record, the voracity of the 
larvae of this species is low compared with that of Crambtcs trisectus, in 
which the average total consumption amounted to over 2,000 millimeters. 
This may be another reason why this species has not caused as serious 
injury as some of the others. 
