6 FARMERS’ BULLETIN 131. 
at this time, comparatively little food. Feeding near the ground, 
sheltered from view by the overhanging grain or grasses, they almost 
invariably escape the notice of the farmer. If the colony of worms 
can be discovered at this stage of their growth the infestation usually 
can be stamped out completely by prompt and vigorous measures, 
such as spraying with arsenicals or covering with straw and burn- 
ing over the infested spot. 
As the young worms grow and feed, their skins become too small 
for them, so presently they split and are shed, and the caterpillars 
begin feeding more greedily than ever. This occurs several times 
during the life of the caterpillar, until the worm becomes full grown. 
The time required for full growth is from 3 to + weeks. The full- 
grown army worm (figs. 1 and 2, >) is a nearly naked, smooth, striped 
caterpillar, about 14 inches long. Its general color is usually green- 
ish, and the stripes, one along each side and a broad one down the 
center of the back, are dark and often nearly black. The stripe along 
the back usually has a fine, light-colored, broken stripe running 
down its center. The color of the body between the dark stripes 
varies from greenish to reddish brown. The head is greenish brown 
speckled with black. 
When an army of these worms is at work in a field the champing of 
their jaws is plainly to be heard, as they greedily devour every blade 
in sight. In this stage the army worm frequently consumes all of 
the food supply near the place where it has developed from the egg. 
When such is the case the caterpillars mass together and crawl away 
in a body in search of other food. It is this habit which has gained 
for the insect the popular name of “army worm.” The massing to- 
gether of the worms affords the farmer an opportunity of destroying 
them in great quantities by mechanical methods described on a fol- 
lowing page of this publication. When the full-grown caterpillars 
cease feeding they usually burrow into the soil to the depth of a few 
inches and by dint of twisting and turning form a cavity or cell 
therein. The worm then begins to shrink and shorten, after which 
the skin splits and is shed and the pupa appears beneath it. When 
the worms are very numerous many of them pupate on the surface 
of the ground, hidden under clods, boards, or bunches of dried grass 
and fallen grain. 
THE PUPA OR RESTING STAGE. 
The pupa (figs. 2, 7, and 4) or resting stage of the true army worm 
resembles a date seed in size and shape, but is more pointed at one 
end. In color it is at first a reddish or chestnut brown, becoming 
almost black as the time for emergence of the moth approaches. Its 
