174: DISEASES OP THE COTTON PLANT. 
These caterpillars were very numerous in the vicinity 
of Columbus, in Georgia, about the end of September and 
the beginning of October, 1854. They devoured grass, 
young grain, and almost every green thing which came in 
their path. Instances have been known in which, urged 
as they were by necessity and starvation, they actually de- 
voured stacks of fodder that were stored away for winter 
consumption. Deep ditches cut in the earth to stop them 
were immediately filled up by the multitudes which fell in 
and perished, while eager millions still rushed over the 
trembling and half-living bridge, formed by the bodies of 
their late companions, bent on their mission of destruction 
and devastation. 
These caterpillars do no essential injury to the cotton, 
especially when weeds abound, as they content themselves 
with the grass growing between the rows ; and, unless very 
numerous, they cannot be classed among those doing much 
harm to the general crop, and are mentioned here princi- 
pally as having been so frequently mistaken for the real 
cotton caterpillar. When pressed by necessity, however, 
as has already been stated, they will feed upon cotton 
leaves. I raised about thirty of them upon this food alone, 
merely as an experiment, and they grew and perfected 
their transformations, although appearing to prefer a grass 
diet if it could be obtained. When about to change, they 
formed cocoons of silk under stones or in the ground near 
the surface, interwoven with particles of earth, and came out 
perfect moths from the 24th to the 30th of October ; and, 
as these specimens were kept in a room without artificial 
heat, I conjectured that those in the open fields would ap- 
pear about the same time. 
At a plantation in the vicinity of Columbus, where the 
caterpillars were very numerous, and had already devoured 
