TREE INSECTS AND THEIR CONTROL 203 
When fully developed the caterpillar 
becomes a chrysalis resembling a sea-shell, 
which is fastened to a limb, and which 
develops into a butterfly, which in turn 
lays eggs. 
damage to the tree the twigs carrying the 
caterpillars should be cut off. When this 
is done the caterpillars may be easily 
destroyed by burning, by dipping in 
kerosene or by crushing. 
Fall Webworm 
Habits This pest may be recognized 
and by its tent-like web containing 
Damage, a quantity of hairy caterpil¬ 
lars together with skeletonized 
leaves, the latter usually brown. The 
young webworm, or pupa, spends the 
winter in silken cocoons, in cracks and 
crevices of fences or tree boxes, under 
doorsteps, on basement walls, or among 
sticks and rubbish. In May the pupa 
becomes a moth, which lays its eggs on 
the underside of leaves. The young 
worms when hatched feed in groups and 
construct their web to cover several 
leaves, sometimes an entire limb of con¬ 
siderable size. In July, when fully grown 
the worms crawl down the tree. A second 
crop develops in August in temperate 
climates, and in the South a third crop is 
Remedies. Like the bagworm, the fall 
webworm has natural ene¬ 
mies, which usually keep it in check. 
When artificial control is necessary, the 
best method is to destroy the cocoon in 
winter by hand picking and burning. The 
burning of the tents is also necessary. If 
foliage becomes affected it should be 
sprayed with lead arsenate. To apply 
the spray a barrel pump mounted on a 
horse-drawn cart may be used in a small 
community, with good results. This 
should have fifty feet or more of garden 
hose. A ten foot bamboo pole, carrying 
the spray nozzle at the end, is helpful in 
causing the spray to reach the upper 
limbs. For larger communities a power 
pump, horse-drawn or motor driven, is 
most efficient. 
known. 
To provide suitable apparatus, the spraying should be cooperative. All trees 
should be sprayed as those left untreated would communicate the web-worms to 
others near at hand. 
Forest Tent Caterpillar 
Habits This is the caterpillar which 
and sometimes is so abundant in 
Damage, forests as to strip completely 
the foliage of trees over hun¬ 
dreds of square miles. In appearance, it 
presents a blue head and it has silver 
spots, diamond shaped, down the back. 
The young caterpillars emerge from the 
eggs when the leaf growth begins in the 
early spring. They feed on the leaves and 
may destroy all the foliage. They are to 
be found in colonies on the trunk and 
larger limbs, and are frequently seen 
hanging by silken threads. Early in June 
they leave the tree and take shelter under 
stones, woodpiles, fences and other hiding 
places, emerging early in July as moths. 
The eggs are laid a little later, around 
slender twigs. 
Remedies. When not destroyed by 
their natural enemies, these 
caterpillars must be given careful atten¬ 
tion as soon as detected. The egg masses 
on twigs may be hand picked and destroy¬ 
ed or they may be daubed with creosote, 
or sprayed with kerosene emulsion or 
with one of the miscible oils of standard 
make. Early spring spraying with lead 
arsenate is effective, when done with 
thoroughness. 
