Fort Worth gazette. [volume] (Fort Worth, Tex.) 1891-1898, 1892-02-28
THE BASKET WORM.

bidding fair to destroy the street and yard
trees of the city. We mention Fort Worth
specially. for the reason that we are seeing
the insect here, but no doubt it is equally
as abundant in other Texas cities, and, in
deed, in other Southern cities, as it is with
US. Last week we printed two letters from
correspondents interesting themselves in
the pest, and for this week we have several
letters running about the same way. I'm
der the circumstances we have thought it
best to give our readers an article on the
insect, without publishing the letters sent
in. Our correspondents will please accept
what we ara about to say as an answer to
all of their favors.
The basket worm, as we are calling it, is
an insect going under different local names
in different localities, such as bag worm,
drop worm, hang worm and tree moth,
The last is probably based on the fact that
it is somewhat like the notorious moth that
cuts our wooden carpets, so far as relates to
the fact that it spins cocoon in which it
lives, and when it moves from place to
place carries its home or covering with it.
Like the carpet or clothes moth it puts its
head and front feet out of its protection
and moves along, dragging that protection
with it, but never comes out. When dis
turbed it simply draws in its head, and
trusting to the strength of its covering re-
mains beyond the reach Of its enemies. OF
course it is much larger than the clothes
moth-its basket or bag or house or what
ever else you may be pleased to call it
measures, on an average, about one and
half inches in length.
The scientific name of the basket worm
is Thyriodopteryx ephemerosformis. Pro
fessor c. V. Riley, now entomologist to the
United States 9spartment of agriculture,
says of it in his bulletin on shade trees:
Although this species was not particu-
larfs destructive to our shade trees in 1886,
yet for the past two or three ye2rs
1t has been on the increase in special locai-
ties in Washington, and at irregular inter
walls becomes great pest when not prop
erly dealt with, especially in the more
southern states.
During winter-time the dependent sacks
or bags of the species may be seen hanging
on the twigs of almost every kind of tree.
If they happen to be on the coniferous
trees, they are not infrequently mistaken
for the cones. In reality they are the COW
erings spun by the worm, and they serve
not only as protection to it, but also to the
eggs. Upon cutting open the larger of these
bags in winter-time they will be found to
contain the shell of a chrysalis technically
called the pupa) which is filed with small
yellow eggs. Each of these is a little
over one millineter in length, cb9Yate in
form, and surrounded by delicate fawn-
colored silky down. In this condition the
eggs remain from fall throughout the Win
ter and early spring.
In the latitude of Fort Worth these eggs
would hatch out minute but active worms
in April, which would begin feeding on the
foliage of the trees upon which they were
Matched, and at the same time begin spin
ming for themselves portable cases in which
TO live. We again copy from Professor
Riley:
The way in which this case or bag is pre-
pared is curious. The young larYa crawls
on leaf and, gnawing little bits from the
surface, fastens these together with fine
silk spun from its mouth. Continually add
ing to the mass, the larva finally produces q
narrow, elongate band, which is then fas-
tened at both ends onto the surface of the
leaf by silky threads. Having secured it
self from falling down by some threads, it
now straddles this band and, bending its
head downward, makes dive under
its back, held down by the band. BY q
quick turning movement the larva regains
its feet, the band now extending across its
neck. 1t then adds to the band at each end
until the two ends meet and they
are then fastened together so as TO form q
kind of narrow collar, which enciroles the
neck of the worm. Far from resting it now
busies itself by adding row after row 10 the
anterior or lower end Of the collar, which
thus rapidly grows in girth, and is pushed
further and further over the maker. =
When in motion or feeding the head and
thoracic segments protrude from. the lower
end OF the bag, the rest of the body being
bent upward and held in this position by
the bag. As the worms grow they continue
TO increase the bags from the lower end,
and they gradually begin TO use larger
pieces of leaves or bits of twigS, or any
other small objects for ornamenting the
outsides. Thus the bags will differ, accord
ing to the different kind of tree or shrub
upon which the larva happens to feed;
those found on coniferOus trees being orna-
mented with the filiform pine leaves, usually
arranged lengthwise on the bag, while those
on the various deciduous trees are more
densely and irregularly covered with bits
ofIeaves interspersed with pieces of twigs |
When the bags, with the growth |
of the larva, get large aud heavy, they are |
no longer carried, but allowed to hang |
down. The worms undergo four molts, |
and AZ eacn OF IneSe PERIODS they close up |
the mouth of their bags TO remain within |
until they have cast their skin and recov-
cred from the effort The old skin is pushed |
out through passage which is kept open |
by the worms at the extremity of the bag. |
The young larya is of nearly uniform |
brown color, but when more fully grown |
that portion of the body which is covered |
by the bag is soft, of light brown color |
and reddish on the sides, while the head |
and thoracic joints are horny and notified |
with dark brown and white. The numer- |
Gus hooks with which the small, feshy pro- |
legs on the middle of the posterior part of |
the body are furnished enable the worm to |
firmly cling to the silGen lining of the bag, |
SO that it can with difficulty be pulled out |
The bag of the full-grown worm is |
slongate-oval in shape, its outlines being |
more oryess irregular on account of irregu-
larities in the orEamentation already de- /
scribed The silk itself is extremely tough |
and with difficulty can be pulled assunder. |
The larvae are poor travellers during |
growth, and though when in great numbers
they must often wander from one branch |
So saeC3her, they rarely leave the tree upon |
N4tS -.l9-ssey were born unless compelled TO |
G3Ss5.5e hunger through the defoliation OF
~ Pcee. when full-grown, however, they |
develop activity, especially when |
very numerous, and, letting themselves
downrSy 4 fine silken thread, travel fast
enough to get across sidewalks or streets.
and often for a considerable distance, until
they reach another tree, which they ascend
This unicf.atOryv dpeira is inStinp-iva. for, 1