8 FARMERS’ BULLETIN 1752. 
tification, as this caterpillar varies in color from light greenish to 
almost black. In their last stages of growth the fall army worms 
consume quantities of food which are really vast in comparison with 
their size. By this time they are devouring every blade and leaf, 
leaving only the toughest parts of the plant stems uneaten. If the 
appetite of the worms is still unsatisfied when all of their local food 
supply has been eaten they mass together and crawl or “march” in 
search of other crops, and this affords the farmer an opportunity of 
killing the pest in great numbers by one of the mechanical methods 
described on pages 14 and 15. 
When the caterpillar of the fall army worm becomes full grown 
it changes to the resting stage, or pupa. As a usual thing, practically 
an inch or two, and by twisting and turning presses the earth away 
from the body on all sides, thus forming a small cell, within which 
it changes to the resting stage or pupa. Asa usual thing, practically 
all the worms enter the soil at about the same time, 
and their sudden disappearance frequently causes 
astonishment and mystification to the uninitiated 
observer. After the cell is completed the cater- 
pillar begins to shrink in length, and presently 
the skin splits and is shed and the pupa appears 
already formed beneath it. 
THE PUPA, OR RESTING, STAGE. 
The pupa (fig. 6) of the fall army worm is 
| somewhat similar to a shelled peanut or date seed 
Pee cat pera in shape and size, but is rounded at one end and 
twice natural size. pointed at the other. The color at first is golden 
Sania or reddish, but finally becomes almost black. The 
skin or covering of its body is smooth and leathery, and it has 
no legs and is unable to move any portion of its body but the tail, 
or abdomen. 
If the soil containing these pupe can be lightly cultivated at this 
time, the insects are easily destroyed, for their underground cells are 
broken up and the pupe are thus crushed or exposed -to the action of 
the sun, rain, and their wild-bird and other enemies. 
The resting, or pupal, stage lasts from ten days to two weeks; 
then the skin of the pupa is burst and the moth or parent crawls 
forth and makes its way immediately to the surface of the ground. 
THE MOTH, OR PARENT, STAGE. 
The moth of the fall army worm is somewhat smaller than that of 
the true army worm, measuring about ? inch in length and a little 
less than 14 inches across its outspread wings, and these wings are 
