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Psyche 6:153-157, 1891.

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PSYCHE.
CADDIS-WORMS OF STONY BROOK.
BY CORA H. CLARKE, JAMAICA PLAIN, MASS.
A
That part of Stony Brook in which I
have made collections lies within the
limits of the City of Boston. It is about eight feet wide, and its depth varies
from two to twenty-four inches. In
some places it flows slowly, in others
rapidly ; here the bottom is muddy, there pebbly. Fresh-water algae of several
species, a great variety of other water
plants, and many different animals are
found in it; among the animals are
fresh-water sponges, Polyzoa, plan-
arians, mollusks, water insects of all
kinds, and occasionally a fish, newt, or turtle. But the most interesting of all
its inhabitants are the larvae of the
Tsichoptera or Caddis-worms. I have
found in all about twenty distinct species, representing each of the seven families. PHRYGANEIDAE. Of this family I
have found only only one representa-
tive, a species of Neuronia. Possibly it is Neuda stygifes, but the only
imago which I have succeeded in rear-
ing was imperfect. It emerged from the
aquarium on April 5th. The larva has
a yellow face striped with black, and is very restless and nervous in its move-
ments, continually travelling about the
aquarium, making sad havoc among its
inhabitants, eating dragon-fly larvae as large as itself, other caddis worms, and indeed any insect which it can catch.
It
also devours raw beef with relish. The
case of this larva (fig. I*) is
made of quadrangular pieces
of leaves, fastened together
by their edges and arranged
in rings rather than in the
spirals which M'Lachlan
e l us is characteristic of 1 @
the genus. Three or four or Fig.1.
sometimes more of these rings, make
the length of the case, which, when full- grown, may be 35 mm. long.? When
the Neuronia larva is not satisfied with its case it bites off a ring at one end, replaces it with a freshly constructed
ring, and then turns within the case, and does the same at the other end. If
pushed out of its case, and deprived of
it, it will make a new one in a night.
Sometimes this species is tolerably abun- dant, and again for several years, it is quite scarce.
LIMNOPHILIDAE. I have found five
or six species of this family. The
commonest of these is Hallems maculi-
pen&, the larvae of which are very
*A11 the cuts are of the natural size excepting fig. 23 and the opercnlum in fig. 8.
+I have found that with most species of caddis- worms the case of the pupa or adult just before pupat. ing is shorter than that of the growing larva.



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154 PSYCHE. [October 1891.
abundant,, crawling over the water
plants in the brook. They
can sometimes be seen under
the ice in a submerged
meadow. The cases (fig. 2)
are made of little sticks and
other vegetable bits, put
on transvessel?, and those of
Fig' ''
the growing larva have a bristling
appearance, probably similar to those
Isaac Walton calls Ruff-coats," but
the case of the pupa is a smooth cylinder. At this time it is about 15 mm. long,
and is closed with a net at each end, as is also the case of Neuronia stygipes.
These nets 01- disks which close the
apertures, are indicated on some of the
cuts. The larvae frequent rather quiet
water, and therefore are comparatively
easy to keep alive in an aquarium, but
all species need especial care during
pupation, which is the critical period
-of a caddis-worm's life. I have found
them pupating in the brook at the end
of May.
A larva, which is probably
that of Limno~hilus $udicus,
makes a slightly curved case
(fig. 3) of little, rounded, im-
bricating bits of leaves. It is
not very common, and I have
Fig.3m
never reared it.
The larvae of Anabolia
sordida are nearly as abun-
dant as those of Hallesus
maculi-pennis; their cases
(fig. 4) are composed of bits
of bark and little sticks,
@
to which are sometimes added
Fig. 4. fragments of moss, a little
sand or gravel or a few shells.
I have
never found a case of any species com-
posed entirely of shells. When sticks are used they are put on longitudinally, and usually project beyond the ends of the
cylinder. During pupation each end is
closed with a net or grating. I have
found a larva pupating at the end of
May and also in June. The adult
case is about 24 mm. long.
I have found larvae similar to those
of Anabolia, in cases made entirely of
pieces of sedge leaves, arranged length- wise with long ~rojecting ends, but
though I once reared the imago, which
also resembles that of Ai~abolia~ I have not succeeded in obtaining its
name.
Another case of about the
same size (fig. 5), with an
imago resembling that of Ana-
bolia, appears to be rare. It
is made entirely of leaves, and
in cross section is three angled,
with projecting corners. This V
larva also is not unlike that of
Figå´3
Anabolia.
A similar larva makes a
case (fig. 6) of bark and
sticks, about 20 mm. long but
slightly flattened, with a little
stick at each side, and imbri-
Fig.6.
cating bits of leaves between.
I sometimes find in the brook
the larva of a species of Steno-
phylax. The case (fig. 7) is
cylindrical, about 22 inm.long,
and is made entirely of gravel.
During pupation it is closed
with a net at each end.
Fig. 7.




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October 1891.1 PL!~'~'-CHE. 155-
SERICOSTOMATIDAE. I have found
six species of Sericostomatidae, of
which the most interesting belong to
Helicopsyche. Species of this genus
make small, snail-like cases of sand,
gravel or mud.
The one whose
case is figured (fig. 8) uses coarse
sand. I find it crawling on stones @
or weeds where the current is Fig.8.
rapid.
In pupation the mouth of this
snail case is closed with an operculum in which is :I small eccentric slit. At the apex of the spiral, which represents the back door of the larva, there is a lacunose disk. These larvae were found pupat-
ing on June 2nd.
A species of Brachycentrus is some-
times common and sometimes
scarce. It makes a quadrangular
case (fig. 9) of a few square bits
of bark, fastened together at their Fig' 9. edges.
Once I found a number of empty
cases (fig. 10) made of sand;
they were small, club-shaped,
and curved, and probably the
Fig. 10.
makers belong in this family.
One of the most abundant species in
Stony Brook (and in other brooks
where I have collected) belongs "near
. Mormonia or Trichostoma."
The case (fig. I I) is arched on
the back, and flat or slightly
concave below, and is made of
gravel, with small stones on each Fig' IT' side, and is about I 2 mm. long. I have
found similar cases in Jamaica Pond.
During pupation the cases are closed at
each end with a small stone, but to in-
sure a current of water through the case, each of these little stones is attached to" the case by a row of short threads, look- ing not unlike the teeth of a moss
capsule. Fig. 12 shows their
appearance at the ventral side
of the head end, where is the
Fig. 12.
point of attachment.
Even more abundant than this species-
is one which makes cylindrical, slightly curved tubes of sand, (fig. 13),
which, when their inhabitants are
pupating, often are found attach-
ed to each other in large masses.
At this time each end of the case Fig. 13. is closed with a grain of gravel, and I
cannot see what provision is made for
the respiratory current. The larva, how- ever, has a small hole at the side of the sand grain which serves to close the pos- terior end of his case. The case of the
growing larva flares somewhat at the an- terior end, but that of the adult is evenly cylindrical. I have an imago of this-
species which I reared from the egg, in
the tranquil waters of my aquarium, but
when the pupae are taken from the
brook, they should be kept in running-
water to transform. On April 17th~
1890, I found multitudes of these cases. in Stony Brook near the Mount Hope
station. I supposed that the larvae had
pupated, since both ends were closed,
but keeping out of water for a few min-
utes one of the stones to which they
were attached, most of the little larvae opened their front doors, and stretched
far out to see what had become of the
brook. By another month, however,
they really had changed to pupae.
Some of the images of this species,.




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156 PSYCHE. [October 1891.
which I reared in my aquarium, came
out with a large tubercle on each side
of the head. These tubercles are sup-
posed to be organs of scent.
Another species of the same family
makes a case (fig. 14) in
shape so like the preceding
that I at first confounded the
two, but the larva of this
latter species has a yellow pig. 14.
head striped with black, while that of
the former has a plain gray head.
Moreover the yellow-faced one uses finer materials, and before pupation shuts
itself in at each end with a disk, in-
stead of a grain of gravel.
One of the
images emerged on June 15th.
LEPTOCERIDAE. (MYSTACIDAE.) I
have found in Stony Brook four
species belonging to this family,
and another in Jamaica Pond. This
last species makes small cases, g mm.
long, of little sticks, arranged trans-
versely like those of Hallesus. The
imago is a pretty little gray spotted
creature, but I have not been able to
ascertain its name.
But the prettiest of my Stony Brook
Leptoceridae is colored a soft yellowish brown, and has very long slender anten-
nae, which indeed are characteristic of
the family. It is said to belong "near
Setodes ignita." The larva is most
abundant on the plants of
Callitriche verna or "water
starwort" from the leaves of
which it usually makes its
case. This (fig. 15) is a deli-
cate tapering cone, about 20
mm. long, and the bits of leaf
Fig. IS.
are arranged side by side in a spiral,
which in some individuals winds to
the right, in others to the left. In a
tube 21 mm. long, there were I I
turns to the spiral. The little larva pro- trudes its long slender legs from the
case, and swims merrily about in the
water. It pupates in June and July,
and is easy to rear in confinement.
The case of the pupa is about 10 mm.
long, and is evenly cylindrical, each end being closed with a disk which has a
small round hole in the centre.
The larva of Mystacides +a also
swims with freedom and is abundant
both in Stony Brook and Jamaica
Pond. Its little case (fig. 16).
about 10 mm. long, varies much,
both as to materials and their
Fig. 16.
arrangement, but is chiefly com-
posed of bits of bark, and little sticks, sometimes filled in with fine sand. It
is easy to rear, and the little black
imago may be recognized by a pecu-
liar bend in each of the upper wings,
which makes them look as if broken.
A species of Molanna, a genus con-
sidered one of the most inter-
esting of those found in
Great Britain, is often quite
abundant on the sandy bottom
of the brook, but I have never
reared it, though it does well ^617-
in an aquarium, until it pupates; it
makes a flattened case (fig. 17), with
an arched dorsal side, which projects
far above the anterior end, so that
nothing whatever is seen of the larva
when it is crawling on the bottom. The
appearance is as if some of the sand




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October 1891 .] F's XYUZ. 157
grains were walking oft' in a mass.
This protecting portico disappears
during pupation.
A larva, which in some years is
quite abundant, spins for itself a case
of black silk, weighted with vegetable
matter. It is about 15 mm. long,
terete, tapering to the rear end, where
there is a small hole. The cases of the
young are quadrangular at the anterior
end, which end during pupa-
tion is closed with a tliick disk,
having in its centre a thinner cir-
cular area perforated with holes.
In the illustration (fig.
18) Fig' 18*
the adult case is represented too small. This species does not bear confinement
well, and I have never reared it.
HYDROPTILIDAE. I have been dis-
appointed at finding only one species of Hydroptilidae in my brook, and this I
have not reared. The case (fig. I 9)
is flat, gray and seed-like, and is @
attached by its edge to the stones Fig. 19. in the brook, where the current is rapid. HYDROPSYCHIDAE. The most in-
teresting species of the order found
in Stony Brook, and also abundant in
various smaller brooks, weaves for itself a little net, probably for the purpose of catching its food. This species, with its nets, has been found to be very com-
mon in other parts of the United States. The net (fig. 20) is up-
right, supported by a
small vertical arch or
ring of vegetable bits,
and the opening of the
Fig-. 20.
larval house is always on the up-stream
side of the net. In some places the
nets and their accompanying houses
are found singly on the bottom, or on
the stones in the brook-in other places. they are thickly clustered together, or, placed side by side, they may extend
nearly across the brook.
The larvae are gray, with an arcuate
body, and tufted gills hanging thickly
from the under side. They pupate in
May. The nets disappear during pupa-
tion, and the houses, which, while the
larvae were active, were shiftless ar-
rangements of loose vegetable bits, or
grains of sand carelessly held togethex
with silk, are now (fig.
21) oblong domes,
strongly constructed of
little stones, and fastened
at their edges to the Fig. 21.
rocks, pebbles or sticks in the brook*
The whole is lined with silk, small
openings being left at each end for the
respiratory current. These larvae die
almost immediately when transferred
from the rapidly flowing streams which
they affect, to the tranquil waters of an aquarium. But like many other sensi-
tive species, the well-developed pupae
can be make to emerge in a set-basiny
which has a constant stream of water
from the faucet flowing through it.
Another species of this family, be-
longing to the
genus Plectroc-
nemia, makes a
tube of mud
(fig. 22) which
I at first thought
must be manu-
factured bv
worm. I saw V
Fig. 32.
the ends of
these tubes projecting from the muddy




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158 PSYCHE. [October 1891.
'bottom of the brook, and by working
my fingers about in the soft mud below
them brought them out uninjured. But
great was my astonishment on opening
one of them to find within a slender, deli- cate, white larva, looking so small in pro- portion to the size of the tube that I could not believe it to be the maker,
till re-
searches into the other tubes revealed
similar occuoants in all of
.I.
them. Fig. 23 represents
the mouth parts of one of
these larvae, enlarged. The Fig- 23.
tube in the centre is the labium (spin-
naret) which spins the silken threads,
the substance used by all caddis-worms
to fasten together the materials of their houses, and fabricate
the gratings or disks
which protect them
during- pupation.
These Plectroc-
nemia cases occur in
colonies, but this
spring, I 89 I, I could
not find any. They
pupate in May, and
;the pupa may be
found in a swelling
of a vertical tube
(fig-. 24).
I do not understand what use
the larvae make of the lateral chambers. Some in my aquarium, however, only
constructed horizontal tubes, in which
they lived and transformed.
RHYACOPHILIDAE. In this family
the pupa is enclosed in a thin brown
leathery cocoon. I have fouiid two
species, but I am not sure whether
I obtained them in Stony Brook, or in
its smaller tributaries. In one of them
the case is of no regular shape, being
composed of a very few stones, propor-
tionately large.
The other case (fig. 25) is
quite peculiar. It is abundant
in the Bussey Brook, and I
have also found it in Brookline
and Dedham. It is about g &?&
mm. long, roundish oblong in 25.