Fort Worth gazette. [volume] (Fort Worth, Tex.) 1891-1898, 1892-03-03
THE BASKET WORM.


Ing to get the people of Fort Worth inter-
ested in an insect pest which at present is
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
iced, 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. Un-
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 are about to say as an answer to
all of their fayors.
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 ike the notorious moth that
cuts our wooden carpets, 50 far as relates TO
the fact that it spins a 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 a
half inches in length.
The scientific name of the basket worm
S Thyriodopteryx ephemerPformis. Pro
lessor c. V. Riley, now entomologist to the
United States department of agriculture,
rays of it in his bulletin on shade trees:
Although this species was not particu-
arly destructive TO our shade trees in 1856,
yet for the past two or three years
{ has been on the increase in special locali-
les in Washington, and at irregular inter-
rails becomes great pest when not prop
srly dealt with, especially in the more
Iouthern states.
During wiuter-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 cOuilerOuS
trees. they are not infreQuently mistaken
FOR the cones. In reality they are the Gov
srings spun by the worm, and they serve
not only as a protection 70 it, but also to the
eggs. Upon cutting open the larger Of these
bags in winl er-time they will be found 20
contain the shell Of n chrysalis technically
called the pupa) which is filed with small
yellow eggs. Each Of these Is a little
over one millimcter in length, obOyate 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 larva crawlS
on a 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
narrow, elOngate band, which is then fas-
tened at both ends onto the surface Of the
eaf by silky threads. Having secured it.
now StraddleS this band and, bending its
head downward, makes 4 dive under
it, turns a complete sOmersaulJ and lies on
Its back, held down by the band. BY a
quick turning movement the larva regains
its feet the band now extending across its
neck. II then adds to the band ut each end
until the two ends meet aud they
are then fastened together SO as to form a
kind OF narrow collar, which encircles the
neck of the worm. Far from resting il now
bushes itself by adding row after row to the
interior or lower enc 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
Ihoracic 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
10 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 ornameuting the
DutsideS. 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 conifeTous trees being orna-
mented with the tihfOrm pine leaves, usually
arranged lengthwiSe on the bag, while those
IN the various decidUous trees are more
ieusely and iFregularly covered with bits
9fleaves interSperSed with pieces of tyigS.
When the bags, with the growth
OF the larVd, gel large and hedVy, they are
no longer carried, but allowed TO hang
down. The worms undergo four molts,
and at each Of these periods they close up
the mouth of their bags 10 remain within
until they have cast their skin and recOv-
cred from the effort. The old skin is pushed
out through a 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 |
lsy the bag IS soft, of light brown color
and reddish on the sides, while the head |
and thoracic joints are horny and mOttled |
with dark brown and white. The numer- |
Gus hooks with which the small, lieshy pro |
legs on the middle of the posterior part of |
the body are furnished enable the worm to |
firmly cling TO the silken lining of the bag, |
SO that il can with difficulty be pulled out |
The bag of the full-crown worm is |
elongdte-Oval In shape, its outlines being |
more or,leSs irregular on account Of irregu- |
larities in the ornameRtatiOn 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 |
To another, they rarely leave the tree upon
which they were born unless compelled TO |
do So by hunger through the defOliation of /
the tree When full-grOwn, however, they |
develop greater activity, especially when |
very numerous, and, letting themselves
down by a fine Silken thread, travel fast
enough to get across sidewalks or streets, |
and often for q considerable distance until
they reach another tree, which they ascend.
H.