Rh a us Ele SL)
2 ¢ TO ea fe
tae oa 7. : ot ZA. ‘
Buiretin No. 21 1921 ENTOMOLOGICAL SERizs, No. 1
‘ie BULLETIN

of the

[LLOYD LIBRARY

BOTANY, akc AND
* MATERIA MEDICA

ta
a
:'o ie

1 iAL& CG LLOYD
7 CINCINNATI, OHIO

ENTOMOLOGICAL SERIES, No. 1

The Biology of

“NORTH AMERICAN CADDIS
ORLY LARVAE

eae | By

me JOHN THOMAS LLOYD

Publications Issued by the Lloyd PDE,

(Complete List to April 1, 1921.) ie.

Bulletin of the Lioyd Library of Botany, Pharmacy, and Materia Medica.

No.

No.

No.

No.

No.

No.

No.

T.

Repropuction Series No. 1, By Joun Ur Lioyp. :
Collections for an essay towards a Materia Medica of the United States a |
by Benjamin Smith Barton, 1798 and 1804.

Repropucrion Series No. 2, sy Joun Uri tore:

The Indian Doctor's Dispensatory, being Father Smith’s advice re-—
specting diseases and their cure, by aes Smith, of otk Miami OUAtTTS
1813. “ei

Mycouocicat Series No. 1.
The Genera of Gastromycetes, by C. G. Lloyd.

Puarmacy Series No. 1, By Joun Uri Luov. ‘ay ;
References to Capillarity. to the end of the year 1990), being Chapeer
VII of “A Study in Pharmacy.” Neha

Mycorocicar Series No. 2.
The Geastrae, by C. G. Lloyd.

Repropuction Series No. 13, BY Joun Uri Lpoat
Materia Medica Americana Potissimum Regni Neese Bits, by Johannes
David Schoepf, 1787. i

Repropuction Series No. 4 By Jonn Uri Lioyp..

An account of some of the vegetable productions naturally growing |

in this part of America, batanically arranged Py the ae Tene sh
Cutler. ; : ;

Mycoxocicat Serizs No. 3. fa a
The Lycoperdaceae of Australia, New Zealand, and Neighboring Islands, ay
by C. G. Lloyd.

Repropuction Series No. 5, By Joun ‘Ur irae: ; :
An investigation of the properties of the Sager! Canadensis or
Puccoon, by William Downey.

Travels through the interior part of North: America in the years 1966,
1767, and 1768, by J. Carver. iy
Libellus de Usu Medico Pulsatillae Nigricantis.

Repropuction Series No. 6, By Joun | Urt Liovp. batt
Hydrastis Canadensis. vee ie nt

ButieTin No. 21 1921 EnTomo.ocica. Serigs, No. 1

BULLETIN

of the

LLOYD LIBRARY
of

BOTANY, PHARMACY anp
MATERIA MEDICA

| eh 0 & CG, LLOYD

CINCINNATI, OHIO

ENTOMOLOGICAL SERIES, No. 1

The Biology of

NORTH AMERICAN CADDIS
FLY LARVAE

By
JOHN THOMAS LLOYD

”

INTRODUCTION.

Caddis-flies, or Trichoptera, are winged insects with somewhat
moth-like appearance, that are mostly nocturnal and usually do not
wander far from the watersides. Only rarely do they become con-
spicuous, and then on account of the great numbers in which they
gather about lights, rather than on account of any striking indi-
vidual habits or appearance. Occasionally they, together with
mayflies and insects of a few other orders, congregate about elec-
tric lights near large lakes and rivers in such numbers that they
become a serious nuisance, and the bodies of their dead collect in
piles that must be removed in wagon loads. Usually, however,
one who is not making a special hunt for them sees no more than
a few individuals that flutter around his light on warm summer
nights preceding storms.

Perhaps the larve, or caddis-worms—known also as “stick-
worms’’—are more familiar to the average layman than the winged
adults. Almost every child has seen a bundle of crossed sticks
jerkily drawn about through the water by an insect with only
head and legs projecting. Not all cases, however, are of the
cross-stick type, and not all are so familiar to the layman. There
are portable cases in almost endless variety of form, and made
of almost every material to be found in the water, and there
are many larve that make no portable cases, but live in silken tubes,
awaiting animal prey or plancton to become entrapped in their
catching nets. A few caddis-worms make no cases at all, but crawl
free among the stones.

Whether the caddis-worms construct portable cases, or silken
tubes, or make no cases until almost time for pupation, they all
secrete a glue, or silk, through openings in the lower lip, or labium.
This silk is produced in large glands within the body cavity.
These glands, like the silk-secreting glands of caterpillars, are
modifications of the salivary glands, to meet the larve’s needs for
silk. The silk is emitted as a liquid, but has the remarkable char-
acter of hardening immediately after expulsion from the larve’s
bodies and of adhering fast to submerged objects, though they be
wet and saturated with water. The silk is not usually spun in fine
strands, as is that of the Lepidoptera, but is more glue-like, form-
ing a homogeneous sheet over the object cemented.

3

INTRODUCTION.

A few caddis-worms that construct portable cases use no other
material than silk in their structure. By far the greatest number
of species, however, use stones or sticks cemented around a more
or less heavy lining of silk. The cases, regardless of their external
form, are circular in cross-section. Some are of uniform diameter,
throughout their length, while others taper, cornucopia-like, from
a broad mouth to a very narrow caudal end. In building their
cases the larvee add new material to the cephalic end. Some species
build rapidly and cut about as much from the caudal ends of their
dwellings as they add to the front ends. These species make tubes
of uniform diameter throughout their length. Other species add
to the front ends of their cases as the larve grow in length and
breadth, but never remove material from the caudal ends. The
result of this form of construction is a case that is of minute size,
but large enough to accommodate a newly hatched larva, at its
caudal end, and gradually increases in breadth as the larva grows,
thus forming a cornucopia-shaped tube. Figures of both types of
cases will be found on following pages.

Toward the close of the larval period there is a change in the
habits of the caddis-worms. They stop eating entirely and fre-
quently hunt some protected spot, such as crevices in bark or roots,
or they burrow into wood or soil. Often the form and material
of their cases is greatly altered, and there is almost always a mesh
or grating spun across the two ends of the case to protect the help-
less pupa against active enemies and the greater peril of silt. After
the mesh is spun the larva becomes sluggish and entirely incapable
of walking. This stage in the larva’s life is called the prepupal
period. It usually lasts but two or three weeks, but in the genus
Neophylax it extends over the greater part of the summer.

During the active larval period, when the caddis-worms are free
to move about and feed voraciously, they lay up a reserve supply of
food to carry them through the transformation period and through
their adult lives, when they feed little if at all. They then pass
through a quiescent or pupal stage. During this period a great
change takes place in the structure of the insect. From the worm-
like larva, fitted for aquatic life and provided with greatly de-
veloped mouth parts and alimentary tract, comes forth a moth-
like, winged insect that is air-breathing and has vestigial mouth
parts and feeble alimentary tract, and seems to have no other object
than to mate and oviposit. So great is the change that no one

4

INTRODUCTION.

could possibly detect the slightest relationship of appearance or
structure between the caddis-worm and the adult caddis-fly.
Though caddis pupz are not active, like the corresponding stages
in some insects, they are not entirely quiescent. There is always
a rhythmic undulation of the abdomen, sending a constant stream
of water through their cases, and during the latter part of their
lives they are capable of walking.

Trichoptera are the only insects, possibly excepting a very few
Diptera (of the genera Simulium and Chironomus), with aquatic
pupz. In several other orders one finds a few species with sub-
merged pupe, but they all tap the stems of aquatic plants, entrap
air in dome-like covers, or in some other way breathe free air.
The pupz or Trichoptera are as much aquatic as are their larve.

The eggs of caddis-flies are round or slightly oval in form.
The eggs of all, except, perhaps, a few of the Rhyacophilide, are
laid in masses of gelatin. ‘The masses, when extruded from the
bodies of the females, are comparatively small, but rapidly absorb
water until they are many times their original size. In form the
gelatin mass, and the arrangement of eggs within the mass, is often
quite characteristic of the species. In laying the eggs, the females
of some species descend beneath the surface of the water and glue
the mass fast to some support. Other species dip their abdomens
into the water while in flight, apparently washing the extruded
mass from the ovipositor, and still other species fasten the eggs to
stick or stones above the water, the young falling to the water
after hatching.

Very little is known of the eggs and egg-laying habits of most
American species.

Trichoptera occur in all parts of the earth where any insects
life can exist, but their greatest abundance is reached in the north-
ern temperate zone, and their numbers of species seem to decrease
as one nears the equator.

They inhabit all kinds of fresh-water situations, from the most
rapid torrents to stagnant swamps and pools. Some species seem
to show a decided preference for temporary pools that are filled
with water when the autumn rains come, and dry completely with
the drought of summer. How these species of Trichoptera, to-
gether with some members of several other orders of insects, pass
over the period of drought is not altogether certain, but evidence
seems to show that they burrow beneath the ground. All known

5

INTRODUCTION.

caddis-worms inhabit fresh water, except a single species from
New Zealand that lives in the ocean, and a well-known terrestrial
species of Europe that lives in the moss on tree trunks.

In economic importance the Trichoptera rank very high as food
for fresh-water fishes. During the summer months the surface-
feeding species of fish, such as the trout, obtain a never-failing
supply of food from the caddis-flies, as they hover over the sur-
face of the stream and lakes. The larvee, however, form a much
more important article of food for fishes than do the adults. Trout
taken from the streams of Ithaca in the early spring are found to
have their stomachs gorged with caddis-worms of the genus Neo-
phylax, and to contain no other food. In New Zealand, Hudson
examined the stomachs of sixty trout caught at all seasons of the
year, and found a total of 5,466 insects. Of these 4,241 were
caddis-worms.

Probably no other order of insects is of as great importance in
the food of wild trout as Trichoptera, and the day will probably
come when caddis-worms are raised by fish culturists as food for
their fishes.

In eating caddis-worms, fishes swallow cases and all, their
stomach becoming filled with sticks and pebbles, as well as with
the bodies of insects.

Aguatic ENvIRONMENT.—To avoid constant repetition on
following pages, a brief description is here given of situations in
which the greater part of the present work on caddis-worms was
done.

Cayuga Lake, a body of water about forty miles long, with an
average breadth scarcely exceeding two miles, lies in the valley
below the Cornell Campus. It is a deep lake with precipitous sides
that rapidly descend to a depth too great for submerged vegetation,
except at the two ends, where there are shoals with luxuriant
growths of aquatic plants that merge into large cat-tail marshes.
The insect fauna of the lake has never been studied.

All of the streams of the region flow into Cayuga Lake. On
approaching it they descend rapidly in a series of falls and tor-
rents. In this region of rapid descent their bottoms are of rock
and they pass through deep gorges.

Higher up they have more the character of the usual streams
throughout the country. They flow in a series of pools with bot-

6

INTRODUCTION.

toms of mud, or silt, or sand, and riffles with bottoms of stones
or gravel.

Most of the large streams of the region have their origin in
summit marshes, whose drainage often enters two different water-
sheds. These marshes have bottoms of deep black muck, and are
covered with dense growth of vegetation. Alders form almost
impenetrable tangles and sedges and grasses, and sometimes bog
moss, sphagnum, grow in thick mats under foot, helping to impede
the off-flow of water. Through these soft muck bogs the streams
meander, their waters always shaded by overhanging alder thickets,
supporting hardly any living vegetation. These upland bogs har-
bor many forms of animal life that are characteristic of such situ-
ations, and of the more northern Canadian fauna.

The largest upland swamps are the McLean Bogs and Michi-
gan Hollow, whose southern drainage flows into the Susquehanna
River, and whose northern drainage forms Buttermilk Creek,
flowing into Cayuga Lake.

More work for the present paper was done in the McLean
Bogs than in all other situations together. These bogs are situ-
ated along, and near, Beaver Creek, an affluent of Fall Creek,
about fifteen miles from Ithaca. They offer not only typical bog
conditions, with areas of sphagnum, areas of sedge, and areas of
alder swamps, but also several cold swamp streams, an open pond,
and numerous large springs.

Since the early days of Cornell, when the hills surrounding the
bogs were covered with an impressive growth of huge hemlock
trees, till the present time, they have been a favorite collecting
ground for students in all fields of biology.

There are also several small lakes in the region. Of these we
are concerned with but a few. Beebe Lake, a dilation of Fall
Creek, which serves as a reservoir for Cornell University, is con-
venient to the Campus, but is not very prolific of insect life. Michi-
gan Pond, at the northern end of Michigan Swamp, has soft mud
bottom and a profuse growth of aquatic plants. It is a rich col-
lecting ground for aquatic insects. Spencer Lake, in the Susque-
hanna drainage south of Michigan Swamp, is a beautiful little
lake which offers a great variety of aquatic situations. It is rich
in caddis-worms, especially the Leptoceride.

With these various kinds of aquatic situations within con-

7

INTRODUCTION.

venient working distance, it would be hard to find a spot more
favorably situated for work on different types of fresh-water life.

Meruops oF CoLLECTING AND REARING.—The methods em-
ployed in collecting and rearing the larve were quite simple. After
the specimens were found, some were put at once into alcohol for
future study, and some into formaldehyde for future examination
of the stomach contents. Others were caged until the time they
emerged, when the species could be determined.

The cages employed were simple cylinders of galvanized
screening, over the bottom and top of which a cloth was tied.
These cages were placed in natural water as nearly like the situ-
ations from which the larve were taken as was possible to find
convenient to Ithaca. The cages were provided with food material
and were partly submerged, care being taken to leave enough space
protruding to give the emerged adults ample room above the water.

In carrying living larve from place to place it was found that
they quickly died if taken from well aerated water and placed in
collecting jars. This difficulty was overcome by wrapping them
in wet cloths. Experience has shown that aquatic insects will live
for long periods of time in cloths that are kept moist, but they
must not be left submerged.

In studying the material in the laboratory, balsam mounts
were made of the frons, legs, and mouth parts. When possible,
the frons and mouth parts were reclaimed from the larval exuvia.
This practice eliminates difficult dissections and gives beautiful
mounts that are much cleaner than can possibly be obtained by dis-
section.

For examining the entire larve a binocular microscope with
various combinations of oculars and objectives was employed.

Many thanks are due to Professor J. G. Needham, Professor
O. A. Johannsen, and other members of the staff of the Depart-
ment of Entomology, Cornell University, for help and encourage-
ment during the preparation of this work.

DisTINCTIVE CHARACTERS OF TRICHOPTEROUS LARVA. —
Aquatic larvee? having three pairs of jointed thoracic legs and a
single pair of abdominal prolegs situated on the last abdominal
segment, and terminating in a chitinous hook. All of the abdomi-
nal segments are soft, except that some members of the family

‘Enoicyla, of the European fauna, is terrestrial.

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SS

INTRODUCTION.

Hydroptilide have small, dorsal, chitinous plates on certain seg-
ments, and a few species in other families have small ventral plates.

DEscRIPTION OF THE Larva. The Head.—The head is
heavily chitinized. On the dorsal surface there is a somewhat
shield-shaped sclerite behind the labrum, which evidently repre-
sents the clypeus and the frons, fused into one piece. As the
frons represents the larger part of the sclerite, and because the
term ‘‘frons” is well established in the nomenclature of other or-
ders of insects applying to the clypeo-frons (“‘clypeus” is used
by most writers on Trichoptera), the term frons is used to desig-
nate the sclerite in the present paper. The shape of the frons
varies in different Trichopterous larvz, and it usually has a quite
distinct pattern of color and muscle-attachment marks, as well as
different distribution of sete, for which reasons it is of great use
in classification. It is also easily recoverable from the larval exu-
via of pupal cases, and often forms the most reliable clue to the
determination of pupz.

Extending back from the frons to the hind margin of the head
is the epicranial suture.

On the ventral surface of the head, behind the mouth parts,
there is a sclerite, the gula, which varies greatly in size and form.
Sometimes it extends to the hind margin of the head, completely
separating the epicrania. At other times it is represented by a
small, triangular piece, behind which the epicrania are contiguous.
At such times the gular suture separates the epicrania behind the
gula.

The epicrania form the greater part of the head, extending
from the mouth parts to the caudal margin, and from the frons
and epicranial suture above to the gula and gular suture beneath.

The antenne are usually so small that they are easily over-
looked; occasionally they are almost as long as the mandibles.
They are located behind the outer angle of the mandibles.

The eyes are located on the outer edge of the dorsal margin
of the head, sometimes on prominences. They are usually jet
black in color and are almost always surrounded by a light-colored
area.

The mouth parts are well developed and are formed for biting.
The mandibles are very heavily chitinized and offer characters
which would be of great taxonomic value, were it not almost im-

10

INTRODUCTION.

possible to get two mandibles into the same position for compari-
son. When seen from slightly different angles, the form of the
mandibles and the comparative size of the teeth, or even the num-
ber of teeth, appear very different. Often the mandibles are
asymmetrical, differing in their armature of teeth, hairs, and
brushes. The labrum is separated from the fused frons and cly-
peus by a membranous hinge by means of which the labrum folds
back within the capsule of the head, often becoming invisible from
above without skilled manipulation. The labrum is usually chiti-
nous, but in some families is membranous. It is provided with a
few large sete, often with dense brushes of hairs, and peculiar,
cycle-shaped, marginal sete, which offer good taxonomic charac-
ters. The labium and lower mouth parts differ in different fami-
lies, but only slight study has been given them and they are used
but little in classification.

The thorax consists of three distinct segments. The dorsal
surface of the first thoracic segment, or pro-thorax, is termed the
pronotum, and is always covered by a heavily chitinized plate,
which extends over the sides of the segment. On the ventral sur-
face of the prothorax there is often a somewhat curved, finger-like
process, of doubtful function, which is found in no other order of
insects. It is termed the “prosternal horn” or the “horn.” The
dorsal surface of the two succeeding segments, the meso- and the
meta-thorax, are termed the meso- and the meta-nota. The meso-
and meta-notum may each bear from one to four chitinous plates,
or they may be entirely membranous. On the sides of the three
thoracic segments, forming supports for the legs, are chitinous
plates which probably represent the episternum and the epimeron.
They offer most excellent taxonomic characters, but as yet are
but slightly studied and their use has been almost entirely neg-
lected. All of the plates of the thorax are armed with character-
istic spines and sete.

A pair of jointed legs is borne by each thoracic segment. These
often arise from bulbous swellings of the integument of the body
which closely resemble the coxe of certain insects and have some-
times been confused with the basal joints of the legs. Commencing
at the basal end of the leg, its segments are as follows: (1) The
Coxa, a large, entirely chitinized segment. (2) The Trochanter,
usually a short, somewhat triangular segment, that is divided by a
suture into two pieces of almost equal length. (In the Lepto-

II

INTRODUCTION.

ceridz, as discussed under that family, there are variations of the
trochanter.) (3) The Femur, usually broad and _ flattened.
(4) The Tibia. (5) The Tarsus, which is a single segment bear-
ing a large claw, usually armed with a tooth.

Gills rarely occur on the thorax.

The Abdomen.—The abdomen consists apparently of ten seg-
ments, or apparently of nine segments. All of the segments, ex-
cept the last, are entirely membranous, except a few Hydroptilide
which bear small chitinous plates on certain segments, and a few
other forms that have some small ventral plates. The first segment
in the case-building forms often bears three “spacing-humps,” or
tubercles. These tubercles are mound-like elevations of the integu-
ment that serve to keep a space between the insect and its case for
the free circulation of the respiratory currents of water. They are
peculiar to the order Trichoptera. One tubercle is located on the
middorsal surface of the segment. It often terminates in a mova-
ble, nipple-like process. The other two tubercles, the lateral humps,
are situated on the sides of the segment and always end obtusely.
On the ventral surface of the segment the cuticula is sometimes
raised into a lip-like fold, or it may be entirely flat. It is provided
with numerous sete, which are arranged in definite order and
often provide convenient means of classification. Some of the
segments between the first and the last, of the case-building caddis-
worms, usually bear a “lateral fringe,” or “lateral line.” This is
a continuous line of delicate hairs, often situated on a fold of the
cuticula, which undulate in a wave-like manner from front to
rear, and keep a continuous flow of fresh water passing through
the case.

Gills, when present, most commonly occur on the abdomen,
where they may be situated near the front or hind margin, or near
the middle of the segment. They are always filamentous, but they
may arise in tufts or singly, they may be branched or unbranched.
Regardless of their location in respect to the cephalic and caudal
margins of the segments, they are always arranged in rather defi-
nite lines known as: (1) The Lateral Series, which is located near
the mid-lateral surface of the body. (2) The Sub-dorsal Series,
which is located above the lateral series, just below the dorsal sur-
face of the body. (3) The Sub-ventral Series, which is located
below the lateral series, just above the ventral surface of the body.

12

INTRODUCTION.

Besides the external gills many trichopterous larve possess anal
gills, which are located within the anus and are capable of protru-
sion. In preserved specimens they are usually completely con-
cealed within the cavity of the body, for which reason they offer
unsatisfactory taxonomic characters. Even the external gills are
not altogether reliable for taxonomic purposes, except in their gen-
eral grouping ; for tufts of gills often contain different numbers of
filaments in different individuals of a species, or even on opposite
sides of the same individual. Also, especially on the more caudal
gill-bearing segments, the gills on some specimens are very feeble,
or drop out entirely, while on other specimens they are well repre-
sented. However, the same type of gills is always found in the
same species, and the gills that are present always arise from the
same parts of the segments.

The terminal abdominal segment bears a pair of more or less
fleshy prolegs, each of which terminates in a movable chitinous
hook. In some of the case-making larve the bases of the prolegs
are fused, forming an apparent tenth segment, while in other spe-
cies they are separate, apparently arising from the ninth abdominal
segment. Ulmer considers ten segments usually present, but the
weight of evidence points to but nine segments, the apparent
tenth being but the fused bases of the prolegs.

DESCRIPTION OF THE Pupa’.—lIn external appearance Trichop-
terous pupe have many of the characters of the adults. Their
legs, antennz, and wing-pads are free from the body, and their
general form is much the same as that of the perfect insect.

The head is formed much like that of the adult. In those
forms that have antenne shorter than the body, the antennez are
straight and are laid close along the sides of the pupe. In forms
with antennz much longer than the length of the body they project
backward along the sides of the insect until nearly reaching the
end of the abdomen, when they turn abruptly and entwine round
and round its caudal segments. The labrum is very different
from that of either larva or adult. It is armed with several
very long spines which probably serve to keep the mesh of
the pupal case free from silt. These spines have characteristic
form and grouping in different species. The mandibles are long
and heavily chitinized, usually possessing several sharp teeth. It

13

INTRODUCTION.

FAMILY CHARACTERS OF TRICHOPTEROUS LARVA.
Prolegs not fused in median line to form an apparent tenth segment.

DorSAL SURFACE LENGTH
FAMILY B ABDOMEN. | OF 9TH ABDOMINAL Tee LABRUM OF
.: SEGMENT FRONS
Much wider | Withchitinous | Absent Entirely Normal
HyYDROPTILIDE than thorax |_ shield chitinized
; Not much With chitinous Absent Entirely Normal
RHYACOPHILIDA wider than shield chitinized
thorax
x ~*~ Not much Without Present. Entirely Normal
HyDROPSYCHID& wider than chitinous shield | Branched | chitinized
thorax
Not much Without Absent Entirely Normal
PHILOPTOMALIDA wider than chitinous shield membran-
thorax ous.
White.
Not much Without Absent Entirely Long.
POLYCENTROPIDH | wider than chitinous shield chitinized | The _
thorax epicrania
barely
meeting
behind its
caudal
margin
ae Not much Without Absent Entirely Normal
PsYCHOMYID& wider than chitinous shield chitinized
thorax

is thought that they are used in cutting through the case at the
time of emerging. The maxillary palpi are well developed and
have the same number of segments as those of the adults.

The thoracic segments are formed much like those of the adult.
The second and third segments have external wing-pads, and all
three segments possess jointed legs. ‘The legs are much like those
of the mature insect, but often possess long swimming hairs to
enable the pupa to reach the surface of the water and a suitable
place for transformation.

The abdomen is- formed much like that of the imago, but is
usually longer and more flexible. Gills and lateral fringe are com-
mon among the pupe. Usually they are found in the same species
that possess them as larvee, but this rule does not always hold true.
The dorsal surface of segment one usually bears a chitinous struc-
ture that may be paired or single. Its general form, together with
its ridges and teeth, offers good family and specific characters.
Other segments of the abdomen bear paired chitinous plates near
their anterior margins, with armature of stout teeth or hooks di-
rected forward. Besides these, segment five bears a pair of plates
on its posterior margin, with teeth directed forward. Rarely simi-
lar plates are found on the caudal margins of one or two other seg-

14

INTRODUCTION.

FAMILY CHARACTERS OF TRICHOPTEROUS LARV&.
Prolegs fused in median line to form an apparent tenth segment.

DorRSAL
TRACHEAL BREADTH | MESONO- | METANO- | FEMUR OF
FAMILY SURFACE
GILLS. of UaBrum|°* LABRUM TUM TUM HIND LEG
Filamen- | With row | Broader Chitinized | Soft Not
CALE OLLIE tous of 20 or than long divided
more
heavy
bristles
In Normal Much Chitinized| 2 narrow | Not
ODONTOCERID& bunches longer plates divided
than crossing
broad median
line and 2
small
lateral
plates
s Absent, Normal Broader Chitinized | Soft Not
SARICOSTOMATID | single or than long divided
bunched
M In Normal Broader Chitinized | Soft Not
OLLANID# bunches than long divided
or
branched
L Absent, Normal Broader Chitinized | Soft Divided or
EPTOCERIDA single or than long apparently
bunched so
P Un- Normal Broader Soft or Soft Not
HRYGANIDZ, branched, than long | with one divided
lateral pair of
series with minute
black hairs plates
L Single, Normal Broader Chitinized| With 3 Not
TMNOPHILIDAE bunched than long pairs of divided
or plates
branched.
Never with
black hairs

ments. This armature, except that of segment one, is subject to
so much individual variation that it is of little systematic impor-
tance.

The caudal abdominal segment bears long, slender processes
armed with long spines. These are probably used, like the long
spines on the labrum, to keep the mesh of the pupal case free from
entangled silt.

Toward the end of the pupal instar it is possible to see many
of the adult characters through the pupal skin. Thus the armature
of the legs and the character of the genetalia can be easily com-
pared to those of the adult.

15

The North American Caddis-Fly Larve

FAMILY PHRYGANEID-.

Of the three of four genera of Phryganeide occurring in
North America, only two genera, Neuronia and Phryganea, have
been recorded in the eastern part of the United States. Of these
the genus Phryganea has four species and Neuronia has eight
species in this region; three of each genus are known in the larval
and pupal stages. The eggs of only one North American species,
Phryganea interrupta, are known.

The larvee of the family are usually among the first aquatic
insects attracting the attention of students of entomology. Large,
brightly colored, caterpillar-like insects that jerkily drag their cases
about in the clear waters, they can not pass unobserved.

Though the larvee do move about and feed in the daytime, they
are typically creatures of the night. If one watches them in an
aquarium he will find that a large part of the day is spent in rest,
with the front end of the case fastened to some support by a film
of silk. When night comes, the cases are loosened and the larve
crawl actively about, greedily feeding upon whatever vegetation
their abode affords. .

The immature stages of the Phryganeide are better known than
those of any other family of American Trichoptera. Our better
knowledge of them is perhaps due to their conspicuousness and
the ease with which they can be fed and reared in captivity. Om-
nivorous plant feeders, and dwellers in ponds or slowly flowing
streams ; furnished with a great area of gill surface which is con-
stantly bathed with changing water pumped by the unceasing
rythmic waves of the body, they thrive in laboratory aquaria.

The greatest danger that besets the captive larve, when sev-
eral are confined together, comes at the time of pupation. After
the earliest have attached their cases and have become inactive,
they fall easy prey to the ravenous appetites of those still active.
In nature, however, due to the burrowing habits of the larve be-
fore their activity ceases, it is probable that they are seldom dis-
turbed by others of their kind.

16

PHRYGANEID&.

DisTINcTIVE CHARACTERS OF THE Larva.—The larve are
brightly colored with dark-brown or black on the yellow back-
ground of the heavily chitinized parts of the head and prothorax.
The abdomen and soft parts of the meso- and meta-thorax, in life,
are green or reddish green.

The body in cross-section is almost circular. The head turns
down at an angle of about 45 degrees; the last abdominal segment
also turns down. The prothorax is heavily chitinized above the
cox and bears no tufts or sete; the meso- and meta-thorax are
entirely soft except a minute pair of bristle tufts. The gills are
finger-like and arise singly, the postsegmental gills of the median
series bear fine black hairs—continuations of the lateral fringe.

DEscRIPTION OF THE Larvai—The Head.—The head is long
and somewhat flattened. Each antenna consists of a single short
cylindrical segment set in a pyramidal base. The tips of the ventral
margins of the epicrania are almost contiguous behind the some-
what triangular gula. The labrum is broader than long, rounded
into two lobes which are separated in front by a narrow area having
its edge indented into about eight scallops; the margins of the la-
brum are bordered with a rather sparse fringe of hair; four sete on
the margin are pale in color and are curved inward so that they lie
almost parallel to the margin, the other setze are normal; on the
under side there are three pairs of spearhead-shaped sete with
their points directed inward, these show through prepared mounts
and often appear as if on the upper surface. The mandibles are
stout, with more teeth on the left mandible than on the right;
brushes on the mandibles are wanting. The lower mouth parts
are well developed; the maxillary palpzee and maxillary lobes are
about equal in length. -

The Thorax.—The prothorax is heavily chitinized above the
base of the forelegs. The venter is soft, except the somewhat tri-
angular sternellum. The “horn” immediately in front of the
sternellum is long, slender, and curved forward. The pleural su-
ture is sunken, giving a grooved appearance to the hind margin
of the segment. The trochantine is acute and spur-like, extending
beyond the margin of the foreleg. Clusters of setz are lacking.

The meso- and meto-thorax are soft, except the heavily chit-
inized episterna and epimera. On the dorsal surface of each of

2 17

NORTH AMERICAN CADDIS-FLY LARV.

these segments there is a pair of slight prominences, each of which
bears clusters of about five large and several smaller sete.

The legs are long, and terminate in slender, curved tarsal
claws; those of the first pair are shortest and stoutest, while those
of the third pair are longest and most slender. The inner margin
of each femur and trochanter is fringed with a dense single line
of pale hairs.

The Abdomen.—The segments are deeply constricted at the
sutures, giving the abdomen a decidedly ringed appearance. The
spacing-humps on the first segment are large; the dorsal hump is
directed backward and bears a pointed nipple-like process at its tip;
it is apparently incapable of motion; the lateral humps lack the
nipple-like process and can be moved at the will of the larva. The
lateral fringe is black, sparse in front, and growing increasingly
denser toward the rear; the gills are long and finger-like, and are
arranged singly; on each segment the hind gills of the medium
line are stoutest and lie close to the body; their firm articulation -
makes it apparently impossible for them to sway in currents, as
do the other gills ; these postsegmental gills bear fine black hairs—
continuations of the lateral fringe. On the dorsal surface of the
ninth segment there is a raised chitinous plate which bears four
prominent, and several small, sete on its hind margin. Above each
proleg there is a line of several sete.

DESCRIPTION OF THE Casks.—The cases are cylindrical tubes
of thin, rectangular bits of leaves arranged spirally (Phryganea,
fig. 41) or in a series of rings (Neuronia, fig. 18). The lining
is a thin sheet of tough but pliable silk.

KEY TO THE GENERA OF PHRYGANEIDA LARV.

A. Frons with median stripe, or with no markings. Case a
spirally wound cylinder.—Phryganea.

A.A. Frons with dark markings, which are not in the form of
a median stripe. Case a cylinder composed of rings of leaf
sections placed end to end.—Neuronia.

Key To THE GENERA OF PHRYGANEIDE Pup®.

A. Mandibles lance-like, or sickle-like, several times as long as
broad.—Phryganea.

A.A. Mandibles rhomboidal, only slightly longer than broad.—
Neuronia. 18

PHRYGANEID&.

GENUS NEURONIA.

Hasrtat.—Neuronia larve may be found in our fauna almost
wherever there are slowly moving streams of spring water. Rarely
they are found along the edge of the large warm streams where
cool seepage enters. They prefer slowly moving water, but seem
to have little preference whether it be a shallow seepage, barely
deep enough to submerge their cases, or the deep pools of upland
streams. In still water only N. concatanata has been taken. This
occurs in Michigan Pond.

LarvaL Hapirs.—The larve of Neuronia are bottom-dwellers
whose habit is to crawl over the floor of their cold spring stream,
or to rest among its trash and litter. They can, and do at times,
climb about on the vegetation, but typically they are of the bottom.

When the season for pupation draws near, the larve of Neu-
ronia burrow into wood, or wedge themselves beneath bark, or in
crevices, as do the larve of Phryganea, or if the stream bottom
be of clay they may burrow into the soil itself. Pupal life beneath
a loose, silty soil would be fatal.

Larve pupating under natural conditions, as described above,
do not shorten their cases. If kept in an aquarium, where oppor-
tunities for burrowing are not at hand, the larve will cut off the
case to a length slightly longer than its body and attach it to some
supporting plant for pupation.

Foop or THE Larva:.—Leaves of all kinds and in all states of
preservation enter into the food of Neuronia larva. Dead leaves,
however, are more frequently consumed than the leaves of living
plants, but the choice seems due to the chance of environment
rather than to a preference of appetite. On the bottoms of the
streams where Neuronia occur, green plants are scarce. When
they do occur they are eaten without discrimination.

DISTINCTIVE CHARACTERS OF THE LArv#.—The only charac-
ters yet discovered for separating the larve of this genus from
those of Phryganea are the color pattern of the frons. All known
larve of North American Neuronia have lateral markings on the
frons, which may connect in U-like forms across the caudal region
of the sclerite. A median stripe is never present.

The larve are slightly more robust than those of Phryganea.

19

NORTH AMERICAN CADDIS-FLY LARVZ.

The spacing-humps are larger, and the abdominal segments less
constricted, giving the larve a less scalloped appearance.

DisTINCTIVE CHARACTERS OF THE Pupa:.—The pupe of Neu-
ronia may easily be distinguished from those of Phryganea by
their short rhomboidal mandibles, almost as broad as long.

DESCRIPTION OF THE CasE.—The cases of the known species
of North American Neuronia are easily distinguished from any
other known cases. They have the form of very slightly bowed
cylinders, varying in length, but always much longer than the body
of the larva, and tapering very little, if at ali. The cylinders are
composed of a series of rings placed end to end. Each ring is
made of broad quadrilateral sections of leaf. The rings are neatly
fitted without overlapping, in the cases of old larve. Young larve
sometimes leave the caudal ends of the leaf fragments protruding
in long strips.

The cases of the larve of American Neuronia differ remark-
ably from those of the European members of the genus. In
Europe the cases are described as spirally built, like those of Phry-
ganea. When a careful study of the adults and larve from Amer-
ica and Europe is made, it may be found that there are generic
differences of structure correlated with this difference of habit
in case-making. _

K&ryY TO THE SPECIES OF NEURONIA LARVA.

A. Mesonotum without chitinous plates. Frons with a dark
mark on each side, not connected to form a U-like pattern.
—WN. postica.

A.A. Mesonotum with two minute chitinous plates near its
cephalic margin. Frons with the dark marginal marks con-
nected behind to form an irregular U-like pattern.

B. Robust larve measuring 30 mm. when mature. Markings
dark.—N. pardalis.

B.B. Less robust larve, not exceeding 20 mm. in length. Mark-
ings less prominent than in N. pardalis.—N. stygipes.

NEURONIA PARDALIS.

Hasrtat.—The larve have been taken only in Argus Brook
and in the old mill-race, at McLean, but adults on the wing in
Michigan Hollow and in Bear Swamp indicate that the species
also breeds in those localities.

20

PHRYGANEIDZ.

LarvaL Hasits.—The habits of N. pardalis do not seem to
differ from those of N. postica.

PrepupAL Hazirs.—No pupz were taken under normal con-
ditions, but probably, if known, their habits would be found like
those of other members of the genus.

In captivity, where no opportunity for burrowing was offered,
the cases were tightly attached to vegetation before pupation took
place.

Foop oF THE Larva:.—No stomach examinations were made,
but the food eaten in captivity does not differ from that taken by
N. postica. Probably in nature the diet of the two species is the
same.

DESCRIPTION OF THE LArvA.—Length, 32 mm.; breadth at sec-
ond abdominal segment, 5 mm.

NEURONIA PARDALIS.

2. Larva. Head and thorax. 6. Larva. Distribution of giills.

3. Larva. Lower mouthparts. 7. Larva. Drag-hook.

4. Larva. Frons. 8. Pupa. Chitinous plates of left
5. Larva. Labrum. side of abdomen.

The Head.—Light straw color with black markings arranged
on the dorsum as in figure 2; on the side there is a black mark
commencing at the prothorax and ending a short distance behind

21

NORTH AMERICAN CADDIS-FLY LARVZ.

the eye, the upper margin of this mark is bordered by numerous
small round spots and near its cephalic end a narrow line extends
downward, connecting it with the black mark of the venter; each
side of the venter is marked by a broad black patch which extends
from the base of the mandibles to the caudal margin of the head;
the mandibles are jet black, except for a brown mark on the outer
margin.

The Thorax —The markings of the dorsum are shown in
figure 2; on each side of the third segment a sharply defined black
mark extends obliquely upward to the caudal margin of the seg-
ment; on the venter there is a black, somewhat triangular mark
reaching from the caudal margin of the segment to the base of
the “horn;” the “horn” is light in color and apparently weakly
chitinized. The second thoracic segment has a group of about
eight sete in a light-colored area on each side of the dorsum; the
sides, except the legs, are without markings; the venter is without
markings; the third segment has a group of about eight sete on
each side of the dorsum, its sides and venter are without markings.

The legs are straw-color marked with black.

The Abdomen.—In life it is dark-green with a distinct reddish
tinge, especially on the dorsal side; the gills are pale reddish; the
arrangement of gills is diagrammatically shown in figure 6.

DESCRIPTION OF THE Pupa.—Description made from a cast
skin. The mouth parts are weakly chitinized; the labrum is rec-
tangular with rounded corners, about 1.5 times as long as wide;
the mandibles are about half the length of the labrum and are
almost as broad as long, a projection on the outer side bears two
prominent sete on its tip; the lateral fringe commences on the
cephalic margin of the fifth abdominal segment and loops under
the caudal margin of the eighth segment; a pair of sucker-like
discs occurs on the dorsal surface of the caudal margin of the last
abdominal segment; each disc has a single seta on its outer mar-
gin and a group of three large sete beneath its cephalic margin;
the first abdominal segment has a striate appearance above, as in
figure 8. The arrangement of teeth on the dorsal plates is serially
illustrated in figure 8.

NEURONIA POSTICA.

Hasitat.—This species is found in cool, slowly moving
streams, fed by springs or in drainage from upland bogs. Like
22

PHRYGANEID&.

other members of the genus, it prefers the deep shade of the forest,
and is often found in streams which are littered with leaves but
void of living vegetation. It occurs sometimes where the seepage
from bogs furnishes scarcely enough water to submerge its case,
and at other times it is found on the bottom of the deepest pools
of upland streams. In the Cayuga Basin it is the most widespread
member of the family.

LarvaL Hasrts.—The larve spend their days crawling about
or resting among the leaves of the stream. At night they are more
active and feed almost unceasingly. They are bottom-dwellers
that seldom climb into the vegetation.

Unlike members of other genera of Trichoptera, this species,
and probably other species of the genus, frequently abandon their
cases. Often during spring the larve may be found without their
cases, and in the winter they have been observed through the thin
ice crawling naked among the leaves on the stream’s bottom.
When they enter submerged trash their cases prove cumbersome,
and are abandoned. How frequently this occurs one comes to
realize when, while seeking the larve, he encounters case after
case without its occupant, and seldom a case inhabited. The form
of the case, also, indicates that they are not long retained. Their
uniform diameter proves that they are constructed more rapidly
than the diameter of the larve increases.

That larve under natural conditions often find and enter their
deserted cases is improbable, but in captivity the cases are usually
reclaimed. Often, when several specimens are kept in the same
aquarium, a caseless larva will enter the rear end of an inhabited
case, crowding the owner out before him. The owner, when so
treated, almost invariably crawls down the outside of the case and
himself enters at the rear. Thus ownership many times alternates
until finally one becomes discouraged and abandons the case to
the other.

A few weeks before time for pupation the larve seek places
of safety in which to spend their inactive period of metamorphosis.
Their hiding place may be the thick mat of roots along the stream’s
edge, or it may be the soil of the stream’s bottom, but more often
it is a water-soaked root or log.

When pupation takes place among roots, the larva crawls deep
into the thickly entangled root-mat of the bordering alders, where

23

NORTH AMERICAN CADDIS-FLY LARVZ.

it makes its case fast with a cement of silk. Here it is protected
against the ravages of prowling enemies and against the greater
danger of suspended silt.

Those larvee which transform in the earth of the stream’s bot-
tom, enter the soil where it is firm and hard; submergence in silt
would mean their destruction. When entering the soil the larva
stands on its head, with its case perpendicular to the bottom, and
slowly enters, dragging its-case with it. I do not know by what
method digging is accomplished.

Foop or THE Larvai.—The larve eat vegetable matter of
almost every kind. In the laboratory they show little preference
between dead or living plants, terrestrial or aquatic. Under nat-
ural conditions, as shown by examinations of stomachs of larve
taken in the streams, both dead leaves and fresh aquatic plants,
when the latter are to be had, are consumed.

Prriop OF EMERGING.—The imagoes first appear early in May
and continue to emerge until late June. In emerging, the pupz
swim to the surface of the water, transform, and take flight with-
out climbing onto any support. Their cast pupal skins are often
common objects along the margins of upland streams.

DESCRIPTION OF THE LAaRvA.—Length, 30—35 mm.; breadth,
4.5—5 mm.

The Head.—Straw-yellow marked with dark-brown as fol-
lows: A mark starting at the base of each mandible extends di-
agonally back along the outer edge of the frons to the hind margin
of the head, almost touching the epicranial suture; a mark begins
behind and slightly below each eye and extends to the hind margin
of the head, almost paratteling the upper mark; a white area sur-
rounds each eye. The under side of the head is slightly cloudy,
but does not have the well-developed smoky stripe of N. stygipes.
The mandibles are dark-brown, except for a triangular spot on
the outer surface, which is lighter. The labrum and the sclerites
of the lower mouth parts are straw-colored, narrowly bordered
with brown.

The Thorax.—The prothorax is straw-yellow, marked with
dark-brown ; the pattern of the dorsal surface is shown in figure 9g.
The epimeron is dark-brown, narrowly bordered with black; the
ventral side of the prothorax is white, with a triangular black
chitinous piece behind the “horn.”

24

PHRYGANEID&.

The meso- and meta-thorax on their upper surface are without
dark marks, but have a pattern of minute white spots arranged in
narrow lines (figure 9) ; the arrangement and extent of this pat-

acer

NEURONIA POSTICA.
9. Larva. Head and thorax. 15. Pupa. Chitinous plates of left
10. Larva. Distribution of gills. side of abdomen.
11. Pupa. Labrum, 16. Larva. Labrum.
12. Larva. Frons. 17. Pupa. Caudal end of abdomen.
13. Pupa. Mandible. Ventral side.

14. Larva. Mandibles, under side. 18. Case of larva.

ern is subject to some variation; the ventral surface is without
marks. The epimeron is brown, with a narrow black mark in the
form of an inverted T.

25

NORTH AMERICAN CADDIS-FLY LARVE.

Abdomen.—The distribution of gills is indicated in figure tro.

DESCRIPTION OF THE Pupa.—Length, 20—25 mm. The
mouth parts are weakly chitinized. The labrum is rectangular,
with rounded corners, about one and a half times as long as wide
(figure 11). The mandibles (figure 13) are a little longer than
wide; a broad lobe on the inner corner of the front margin is
without sete; a smaller, somewhat finger-like lobe on the outer
corner bears a pair of long sete on its tip.

The lateral fringe commences on the cephalic margin of the
fifth abdominal segment and loops under the caudal margin of the
eighth segment. The last abdominal segment is deeply notched,
as shown in figure 17; the sides of the notch are flat and disc-like
on their dorsal surface. The shield on the dorsal surface of the
first abdominal segment is finely striated with transverse marks,
as shown in figure 15. The chitinous plates of the succeeding seg-
ments are shown in the same figure.

NEURONIA STYGIPES.

Hasitat.—The only locality record for the immature stages
of this species is a short area near the headwaters of Argus Brook,
in the McLean bog. In this region the larve are not uncommon.

LarvaL Hasits.—The larve wander actively about through
the trash of the stream’s bottom until the middle or latter part of
April, when they burrow into the soil or into dead wood for pupa-
tion.

PERIOD OF EMERGING.—The habits of the species when emerg-
ing are like those of NV. postica. In captivity emergence took place
during the last two weeks of May. During the same period adults
were common along the stream where the larve were found.

The adults were seen only close to the stream from which they
emerged. Here they flew about with slow, jerky flight close to the
low vegetation beneath the dense alder thicket, or skimmed the
surface of the small stream. When resting they sought the shelter
of low weeds or grass.

Due to their habit of flying during the light of day, and of re-
maining close to the borders of the stream, the adults of this species
are more readily seen than are those of other species of the genus,
which are nocturnal and wide wanderers.

26

PHRYGANEID&.

Foop or Larva:.—The stomachs examined contained nothing
but fragments of disintegrated leaves—the only soft vegetable mat-
ter in the stream where the larve were found. It is probable that
this species, like N. postica, has little preference for the kind or
condition of the leaves it eats, and that the variety of its diet is
in about the proportion of the variety of the soft plant materials in
the water it inhabits.

DESCRIPTION OF THE Larva.—Length, 20 mm. ; breadth, 3 mm.
No structural or color characters have been found to separate
the larva of this species from NV. pardalis.

NEURONIA STYGIPES.
19. Larva. Head and thorax. 20. Larva. Frons.

Head.—Straw-yellow marked with dark-brown, as shown in
figure 19. A dark-brown mark starting at the base of each man-
dible extends diagonally back parallel to the outer margin of the
frons, to the hind margin of the head, where the two almost touch
the epicranial suture; a dark-brown mark begins slightly behind
and a little below each eye, and extends back to the hind margin
of the head; on the under side from the mouth parts to the hind
margin the head is clouded with smoky brown; between this
clouding and the postocular mark the straw color of the head is
unshaded; a narrow white area surrounds each eye. The frons
(figure 20) has the straw-yellow ground color of the rest of the

27

NORTH AMERICAN CADDIS-FLY LARVE.

head; a dark-brown mark begins slightly behind each mandible
and follows the inner margin of the frons until nearly reaching
its caudal angle, where it makes a U-like curve, leaving a small
area of the caudal part of the frons unmarked.

The Thorax.—The sternum of the prothorax is straw-yellow,
the dorsum marked with a somewhat variable pattern of smoky
brown, as shown in figure 19; the episternum is smoky brown in
color, narrowly bordered with deep black along its hind and lower
margins; on the under side the prothorax is straw-yellow, except
the chitinous triangle, which is dark-brown. The mesothorax has a
variable pattern on its dorsal surface; it also has two dark-colored
chitinous plates near the mid-dorsal line. The metathorax has a
variable pattern on its dorsal surface.

The Abdomen.—The soft abdominal parts of the material at
hand have been injured by drying.

GENUS PHRYGANEA.

Hasrrat.—In this region Phryganea larve have been found
only in the ponds and pools of the Renwick marshes and in Mich-
igan Pond. Occurrence of adults at Sheldrake Point, where there
are similar ponds, and on the campus, near Beebe Lake, makes it
seem probable that the genus is not uncommon where suitable
ponds of thick submerged vegetation exists.

LarvaL Hapritrs.—Phryganea larvee dwell, for the most part,
among submerged plants above the water’s bottom. They are
among the few Trichoptera larve that can readily be taken with
a water net. In moving from place to place, however, when the
branches of the supporting plants are not intermixed, they must
become bottom-crawlers. Unlike Triznodes, a genus of Lepto-
ceridee, with which their cases and habits have some things in
common, they are not provided with swimming hairs, and are in-
capable of progress by swimming. Phryganea larve differ from
the larvee of Neuronia in their persistent occupation of their cases.
They never abandon their cases to wander naked through the
water. Correlated with this habit one finds their cases more
tapered than those of Neuronia, indicating that they have been
retained through a period of growth.

In preparing to pupate, the larve of Phryganea leave their
abode among the living plants and travel to some submerged log

: 28

PHRYGANEID&.

or chunk of wood. Here they turn at right angles to the surface
and slowly burrow into the wood until the last bit of the case is
concealed. The operation sometimes requires several days of
labor. When sufficient depth is reached the larva spins a silken
mesh across each end of the case.

Sometimes, when the bark of the log is loose, the larve take
advantage of the natural condition and pupate between the bark
and the wood, or they may wedge themselves into some natural
crevice. Boring into the wood, however, seems the most common
method of concealment.

Foop oF THE Larva:.—Stomachs of larve taken under natural
conditions contained green plant tissue of various species. Ap-
parently the larve feed upon green tissue because of their habit
of living among living plants, where the accumulation of dead ma-
terial does not occur, rather than through any choice of appetite.
In aquaria, among a mixture of living and dead plants, they dis-
played no preference for either sort. Each was eaten with equal
greed.

DESCRIPTION OF THE LArva.—The larve of the known species
of North American Phryganea can most easily be distinguished
from the larve of Neuronia by the color patterns of the frons.
In Phryganea the color is confined to a medium stripe, except in
P. vestita, in which a pattern is entirely absent.

The larve are slightly more slender than those of Neuronia.
The spacing-humps are not quite so strongly developed, and the
abdominal segments are more rounded, giving them a more pro-
nounced scalloped appearance.

DESCRIPTION OF THE Pupa:—The pupe of Phryganea differ
from those of Neuronia in having long, slender, lance-like mandi-
bles—many times as long as broad.

DESCRIPTION OF THE CasE.—The cases of Phryganea have the
form of straight tubes (figure 41) composed of narrow strips of
leaf arranged in spiral form around the circumference of the case.
The spiral of the same species is sometimes wound from right to
left, sometimes from left to right. The cases of mature larve are
tapered very slightly, if at all, but those of immature larve taper
much more than do those of immature Neuronia larve. The
young of both genera often fail to cut the leaf fragments used in

29

NORTH AMERICAN CADDIS-FLY LARVZ.

the construction of their cases into the rectangular form charac-
teristic of older larve. Such cases, (figure 40) with their long,
protruding ends of leaves, appear superficially very different from
those of mature larve. Careful examination beneath the protrud-
ing ends, however, will reveal the characteristic ringed or spiraled
arrangement of the bases of the untrimmed leaves.

The cases of Phryganea larve might, from description, be con-
fused with those of Triznodes. In Triznodes the case is much
smaller and more flexible. Its spiral is more plainly apparent than
the spiral of Phryganea, and the leaf fragments are much narrower
—in most examples almost thread-like.

KEY TO THE SPECIES OF PHRYGANEA.

A. Frons without dark markings.—P. vestita.

A.A. Frons with a median mark.

B. Median mark extending the entire length of the frons. Dorsal
surface of the prothorax margined in front and behind
with dark. No conspicuous dark markings on meso- and
meta-thorax.—P. interrupta.

B.B. Median dark mark not reaching the hind margin of the
frons. Prothorax not margined in front and behind with
dark, but with two converging dark marks. Meso- and
meta-thorax with two nearly parallel longitudinal dark
marks.—P. cinerea.

PHRYGANEA CINEREA.

Hapsits.—This species is not known to me in life. The speci-
mens from which the description is made were taken by Dr. C.
Betten at Old Forge, New York.

Although none of the larvee were reared, it seems probable that
they are P. cinerea, for all known species of the genus, which might
occur in this state, have been reared, except P. cinerea and P. im-
proba. Improba is a very rare species, represented in collections
by only a few specimens. Cinerea is more common and was taken
at Old Forge by Dr. Betten during the season in which he collected
the larve.

When collected, August 8th, one larva had spun the sieves
across the openings of its case, indicating that its growth was com-
plete and that it would have emerged about one month later.

30

PHRYGANEID&.

DESCRIPTION OF THE |,ARvA.—The length of the larve is 17
mm., and the breadth at the third thoracic segment is 2.5 mm.

PHRYGANEA CINEREA.

21. Larva. Head and thorax. 23. Larva. Distribution of gills.
22. Larva. Frons.

Head.—Figure 21 shows the color pattern of the head. Its
ground color is straw-yellow, marked as follows: A median mark
begins on the front margin of the frons and extends back about
three fourths of its length; a mark begins above the base of each
mandible and extends diagonally back between the eye and the
frons to the hind margin of the head; a line begins behind and
below each eye and extends diagonally upward and backward to
the hind margin of the head, where it meets the dorsal marks of
the thorax ; the under side of the head is without marking, except
for a narrow margin of brown at the base of the mouth parts. The
eyes are black.

The Thorax.—The prothorax is straw-yellow with dark marks.
which form continuations of the lateral marks of the head and
converge toward the mid-dorsal line as they approach the hind
margin of the segment; the epimera are dark-brown.

The meso- and meta-thorax are marked above with two almost
parallel dark stripes which form continuations of the dark marks

31

NORTH AMERICAN CADDIS-FLY LARVZE.

on the prothorax and extend to the hind margin of the metathorax.
Each epimeron is marked with dark-brown.

The legs are straw-yellow with a dark-brown mark on the
front of each coxa.

The Abdomen.—The abdomen is marked on its upper surface
with two parallel dark stripes, which form continuations of the
thoracic markings. These marks are less conspicuous than those
of the thorax and become fainter as they reach the caudal seg-
ments.

The gill arrangement is shown in figure 23. The caudal gill is
lacking from the ventral series and segment 8 is without gills.

PHRYGANEA INTERRUPTA.

LarvaL Hapsrrat.—In the region of Ithaca larve of P. inter-
rupta have been taken, together with those of P. vestita in Michi-
gan Pond and in the pools about the University Biological Field
Station. Vorhies, who reared this species at Madison, Wisconsin,
found it common in several situations of standing water “where
Elodea occurs.” In our locality the species is found in some situ-
ations where no Elodea grows, and it seems to us improbable that
the presence of Elodea has any influence on the distribution of the
larve.

LARVAL Hasits.—The activities of the larve, so far as known,
are like those of P. vestita.

Although pupation takes place and the adults are on the wing
together with those of P. vestita, the larve obtain their growth
very much sooner than those of that species. By the first of Jan-
uary the larve of P. interrupta have obtained full growth, measur-
ing thirty millimeters in length. At the same time the larve of
P. vestita, from the same situation, measure only twelve to twenty
millimeters in length.

In preparing to pupate, the habits of this species do not differ
from those of P. vestita.

Prriop oF EmMEeRcING.—Adults emerged from the last of May
until the latter part of June.

Foop oF THE Larvai.—The stomachs of specimens examined
contained about the same proportion of dead and green plant tissue
found in the stomachs of P. vestita.

32 :

PHRYGANEID&.

24.
Zo
26.
27.

28.
20.
30.

Vorhies speaks only of Elodea as food of the larve. No Elodea
occurs in some of the situations of our region where the species is
common. Probably Vorhies would have found his specimens feed-
ing as readily on the leaves of other plants if opportunity had of-
fered.

PHRYGANEA INTERRUPTA.

Head and thorax.
Lower mouthparts.
Front leg.

Caudal end of abdo-
men, dorsal.

Labrum.

Middle leg.

Hind leg.

1. Egg mass.

. Case of pupa.

3. Larva. Distribution of gills.

. Pupa. Caudal end of abdomen,

ventral side.

. Larva. Labrum.
. Larva. Frons.
. Pupa. Mandible, lateral view.

NORTH AMERICAN CADDIS-FLY LARVE.

DESCRIPTION OF THE LArva.—Length, 30—35 mm.; breadth,
5 mm. The head and thorax are considerably broader and flatter
than those of P. vestita.

Head.—The ground color is light straw-yellow. A dark-brown
mark begins at the front margin of the head behind each mandible
and extends obliquely back, paralleling the side of the frons, to
the hind margin of the head, where it almost touches the mid-dorsal
line. A dark-brown mark begins a short distance behind and be-
low each eye and extends back to the hind margin of the head. The
eyes are narrowly bordered with white. The frons is traversed
from the front to the hind margins by a dark-brown median mark
with irregular margins (figure 36).

The mandibles are dark-brown and black, except a somewhat
triangular mark on the outer margin, which is paler; other parts of
the head are straw color.

The Thorax.—Straw-yellow, marked on its upper surface
with brown, as shown in figure 24. The pronotum is margined in
front by a narrow line of very dark brown; behind this line there
is a brown mark, on its hind margin there are similar but narrower
markings of brown which, in the normal position of the larve, are
covered by the metathorax.

The meso- and meta-thorax are light-green in life, with fine
colorless markings, which are subject to considerable variation in
pattern.

The supra-coxal plates are dark-brown, margined with black.

The legs are straw-yellow with narrow black marks on the
outer edges of the bases of the cox, and shadings of light-brown
on the margins. The outer surfaces of the coxe of the first and
second pairs of legs are thickly set with minute thorns, plainly
visible only in prepared mounts, but much larger than those of
P. vestita, in which species the thorns are visible only with the
compound microscope.

DESCRIPTION OF THE Pupa:.—Only cast pupal skins are in our
collection. Vorhies states: “Length, 25—28 mm.; width, 6 mm.
Antennz extending to the sixth segment. Body in life, green; a
fuscous band extending along the dorsal wall of the abdomen on
either side.”

Our cast skins show the following characters: The mandibles
(figure 37) are almost twice as long as the labrum. ‘The lateral

34

= PHRYGANEID/.

fringe is dense and black. The anal appendages (figure 34) are
short.

DESCRIPTION OF THE Eccs.—The eggs have been found by
Vorhies, who states: “An egg mass taken from vegetation in the
water of Lake Wingra on July 21 proved to be of this species. It
consisted of a cylindrical mass of clear jelly 6 mm. in diameter, in
which the eggs were imbedded; the ends of this mass were bent
around and united so as to form a perfect circle, with a diameter
of 3 cm.”

Figure 31 represents an egg mass of an undetermined species
of this genus which was collected in a pond at North Fairhaven,
New York.

PHRYGANEA VESTITA.

Hasitat.—The larve have thus far been found in only two
localities—Michigan Pond and the pools about the Cornell Bio-
logical Field Station. In these localities they are not uncommon.

LarvaL Hasits.—From late summer until early spring the
larvee spend an active life on submerged vegetation. Rarely they
are found crawling on the bottom.

In early spring, when time for pupation draws near, the
larve seek the protection of some soggy submerged stick or log.
Into this wood they slowly bore, dragging their cases with them,
until they are completely beneath the surface—sometimes sev-
eral inches beneath the surface. The work of boring is accom-
plished very slowly. The only larva observed during the process
was found in the Field Station pools. When discovered, this
larva had bored about one-half inch into a piece of soaked wood.
The front end of the case was fastened firmly within the hole,
and the hind end protruded from the surface at right angles.
From day to day it drew farther into the wood until, at the end of
a week, only the tip of the case remained protruding. During the
operation the chunk was left in the pool where found. No dust
or fragments of wood accumulated about the larva, and it was not
known whether the waste was torn loose and extruded between the
larva and its case, or whether it passed through the larva’s ali-
mentary tract. The larva’s case fit so snugly in the hole that
nothing could have passed outside it.

All pupz found were beneath the surface of wood, usually in

35

NORTH AMERICAN CADDIS-FLY LARVZE.

holes which they had evidently made for themselves, though some-
times they were in cracks or between the bark and the wood. The
front ends of the cases were fastened tightly, sometimes so tightly
that pressure broke them before pulling them loose from their
support.

Foop oF THE LARva:.—Stomachs examined contained almost
entirely green leaves of aquatic plants. Only a few contained dead
vegetation, but the choice undoubtedly was due to the environment
of feeding, rather than to any choice of the larve.

Periop oF EMERGING.—Specimens emerged June Io to 20.
Emergence was not observed, but the similarity of Phryganea
pupz to those of Neuronia in habitat, habits, and structure in-
dicates that emergence is accomplished as in that genus.

DESCRIPTION OF THE Larva.—Length, 25—30 mm.; breadth,
3.5 mm. In life the color of the chitinous parts is pale straw-
yellow with dark-brown markings.

Head.—The color pattern of the upper surface of the head is
shown in figure 38; its ground color is straw-yellow, lighter around
the eyes; a dark-brown mark extends back from the base of each
mandible, touching the margin of the frons, and passing on to the
hind margin of the head; on the sides of the head an oblique dark
mark begins behind each eye and extends back to the hind margin
of the segment, paralleling the dorsal dark mark. The eyes are
jet black. The frons (figure 43) is straw-yellow without mark-
ings, but is slightly darker than the ground color of the head. The
mandibles are stout; the left mandible has three teeth above and
three below, while the right mandible has but two teeth above and
two below.

The Thorax.—The prothorax is straw-yellow with two oblique
dark-brown marks, forming continuations of the lateral marks of
the head, on its upper surface. The posterior sclerites of the pro-
pleura are dark-brown, margined with black on their caudal and
lower margins.

The meso- and meta-thorax are brownish green in life, marked
somewhat as shown in figure 38; the markings of these segments
vary somewhat in different specimens.

The legs are straw color with dark-brown markings on each
coxa and a mark of lighter brown along the back of the front
femur. The legs are more slender than those of P. interrupta, and

36

PHRYGANEIDE.

the thorns on the first and second cox are much more minute—
invisible except in prepared mounts under the compound micro-

PHRYGANEA VESTITA.

38. Larva. Head and thorax. 43. Larva. Frons.

39. Larva. Labrum. 44. Larva. Front leg.
40. Case of young larva. 45. Larva. Middle leg.
41. Case of old larva. 46. Larva. Hind leg.

42. Larva. Distribution of gills.
37

NORTH AMERICAN CADDIS-FLY LARVE.

DESCRIPTION OF THE CasE.—The case is tubular, tapering
gradually from front to rear, and is not curved (figure 41). It
is made of narrow, somewhat quadrangular, bits of leaves arranged
in spiral form, wound from right to left. Different cases vary
considerably in size, but usually they are about 5 cm. long, 5 mm.
wide at the front, and 3 mm. wide at the hind end. The spiral
usually has from Io to 12 turns.

The case of the pupa is about 36 mm. long and has little or no
taper. It is sealed at both ends with a sieve of silk.

FAMILY LIMNOPHILID:.

Hasitat.—Limnophilid larve are fitted for life in almost
every aquatic situation. In pond and slow-moving streams, espe-
cially those that dry completely during the drought of summer,
their numbers far outnumber all other Trichoptera together. As
the water becomes more swift the number of species becomes less,
until in the swiftest water, in which loose stones come to rest, one
finds only species of the genus Neophylax, but these often in great
numbers. ‘They are absent from the brinks of falls and from the
parts of streams where the waters rush over bare bedrock.

Apparently in direct relation to the kind of water inhabited
the development of gills has taken place. In those species that
inhabit standing water the gills are large and numerous—often
many-branched. In species of faster moving water the gill sur-
face is noticeably less, and in Neophylax—the Limnophilid of the
rapids—the gills are few and are reduced until hardly more than
thread-like rudiments.

To this family belongs the European Enoicyla, which has the
only terrestrial larvee known to occur in the order Trichoptera.

Larva Hasirs.—Little can be said that will cover the habits
of all of the Limnophilid larvee. ‘The habits of each species are
discussed separately on the following pages.

In preparing for pupation the larve retire to some secluded
spot where there is little danger of molestation during the quiescent
pupal period. One species at least, Limnophilus indivisus, buries
itself among the submerged roots of sedges; more often the larve
hide in the crevices of sticks or stones. So far as we know, only
the larve of Neophylax remain in the open. These larve attach

38

LIMNOPHILIDE.

their tough stone cases to the edges of rocks in swift water, without
search for protecting crevices.

In this family, with the exception of the genus Neophylax, we
have noted no attempt at gregarious grouping, except when acci-
dent brings the larve together. In Neophylax there is an unmis-
takable gregarious instinct developed when the prepupal period
approaches. At this time larve gather in compact masses on cer-
tain parts of certain stones, while other similar stones in the same
part of the stream remain uninhabited.

Foop oF Larva:.—It seems probable that the larve are al-
together herbivorous when living under natural conditions, but’ in
the confines of aquaria they will often become carnivorous, or even
cannibalistic.

The vegetation eaten by most. species consists of vascular
plants, living or dead, with more consideration for the convenience
of the larve than for the condition of the food.

A few species, such as Limnophilus submonilifer, rasp the soft
outer portions from submerged sticks and stems, and thus procure
a diet that is often a mixture of higher plant tissue and diatoms—
sometimes it is almost altogether diatomaceous ooze.

Periop oF EMERGING.—From the time when Platyphylax be-
gins to emerge, while the first warm spring sun still shines on the
snow of late winter, until Neophylax and a few others cease their
flight in the snow of early winter, there is no period without some
species of Limnophilid.

Though on the wing from the snows of spring till the snows
of fall, the adults are found in maximum numbers of species dur-
ing late spring or early summer. In June, for a short time only,
the greatest number of species are in flight, but there are other
species for every period of the summer, and a few, such as Limno-
philus submonilifer, continue to emerge during the greater part of
the summer. Such species do not have a definite season when all
the individuals occur as larvee, pupz, or adults, but can be found
in all stages during most of the summer.

Description oF Larvai.—tIn form the larve are cylindrical.
The head fits well into the first thoracic segment and is carried
pointing downward at a decided angle to the rest of the body. The

39

NORTH AMERICAN CADDIS-FLY LARVE.

first and second thoracic segments are chitinized dorsally, and the
third segment bears three pairs of chitinous plates.

The Head.—The head is generally oval, sometimes decidedly
tapering toward the mouth parts. The gula is triangular or elon-
gate, and the epicrania are contiguous, or nearly so, behind its base.
The labrum is broader than long, variously armed with bristles and
hairs. ‘The mandibles are stout, with blunt rounded teeth, and a
pair of sete on the outer surface and a brush on the inner surface.

The Thorax.—The dorsal surface of segments 1 and 2 is com-
pletely covered by chitinous shields. On the ventral surface of
the prothorax there is usually a slender curved “horn” directed for-
ward between the bases of the forelegs. The metathorax is soft,
except for three pairs of chitinous plates; of these the lateral pair
is somewhat crescentric in form and occurs slightly above the bases
of the metathoracic legs; the median pair is small and somewhat
oval or triangular, and is located near the cephalic margin of the
segment; the second pair is small and of varying form, and is
located more laterally and posteriorly than the median pair.

The Abdomen.—The abdomen is cylindrical in cross-section
and of nearly uniform diameter throughout its length. Its first
segment is provided with three more or less perfectly developed
“spacing-humps” or callous spots. Gills are always present, but
vary greatly in number and arrangement; they occur on the first
segment, so far as known, only in an unidentified species of the
genus Limnophilus. The lateral fringe is present, but is sometimes
very feeble. The last segment bears a chitinous plate on the dorsal
surface. The first segments of the prolegs are fused to form an
apparent tenth segment.

DESCRIPTION OF THE CasE.—The larve of the various genera
of the Limnophilidz make cases of great variety of form, and of
almost every obtainable material.

In spite of their great variety of form and material the cases
can, with a few exceptions, be readily determined by an observer
with a little experience.

To this family belong the log-cabin type of cases; the cylin-
drical cases with little or no taper, made of rough fragments of
bark, or sticks, or leaves, shells, or seeds ; the cylindrical cases with
heavy ballast sticks at the sides ; also cases made of leaf fragments

40

LIMNOPHILIDE&.

that are triangular in cross-section ; and flat, two-sided cases of leaf
fragments.

All members of the family are makers of portable cases, but,
so far as known, there are no spiral cases, and none made of a
series of rings placed end to end; there are no cases that are four-
sided in cross-section, and none that are made entirely of silk.

In the genus Neophylax the larve make cases of sand with
large ballast stones at the sides, which are very similar to cases
made by some of the Sericostomatide, but are more slender,
smaller, and made of lighter material. A few genera (only Platy-
phylax as yet described from America) make curved, tapering
cases of sand grains that quite closely resemble the cases of certain
Leptoceride. Though there are fairly constant characters for
determining the cases of the family, it is impossible to give char-
acters for separating all of the cases generically or specifically.
Often the cases of different individuals of a single species differ
more widely from each other than from cases of species of widely
different genera.

Limnophilide with gills arising in tufts of two or more. A dark colored longitudinal

line on frons.

COLOR PATTERN ON| LATERAL MARGINS OF
NAME RONS DARK MarK ON FRONS PROTHORAX
GLYPHOTAELIUS Black longitudinal} Parallel, not widening | Light, except dark brown
HOSTILIS mark to include lateral sete | on frontand hind margins,
of front row and median furrow
Brown Not parallel, widening | Mottled with brown with-
Torus longitudinal mark,| toward front to include | out distinct light colored
usually forked at | lateral sete of front band behind median
anterior end Tow furrow
HALEsus Black longitudinal) Not parallel, widening | Solid brown-black along
INDISTINCTUS mark toward front to include | front margin. A broad
lateral sete of front light band behind trans-
row verse furrow
LImNopuHILus Black longitudinal} Not parallel, widening | Solid brown-black along
INDIVISUS © mark. Sometimes} toward front to include | front margin. A broad

forked at anterior
end.

lateral sete of front
row

(Tables continued on page 42.)

41

light band behind trans-
verse furrow

NORTH AMERICAN CADDIS-FLY LARVE.

LIMNOPHILID2 WITH GILLS ARISING SINGLY.

EAcH SIDE ea
ea BRowN MARKS PROTHORACIC | OF Meso- | SPACING ee
NAME ON FRONS HorN THRacic | Humps |, 5 IRST
Hint BDOMINAL
SEGMENT
Muscle-attach- Absent Margins All With pair
NEOPHYLAX ment marks only only deep | present | of thumb-
CONCINNUS black like pro-
jections
F Muscle-attach- Absent Margins | All Without
NEOPHYLAX ment marks only only deep | present projec-
AUTOMNUS black tions
Muscle-attach- Present Margins Dorsal Without
ARCTOECIA ment marks only only deep | hump projec-
MEDIALIS black absent, tions
lateral
humps
present
Mottling besides Present A deep All Without
ASTENOPHYLAX muscle attach- black isol- | present projec-
ARGUS ment marks ated spot tions
in each
outer
caudal
angle
Mottling besides Present Margins All Without
HALESUS muscle-attach- only deep | present, projec-
GUTTIFER ment marks black dorsal tions
hump
nipple-like
Mottling besides Present Margins Flattened | Without
PyYCNOPSYCHE muscle-attach- only deep | or slightly | projec-
SCABRIPENNIS ment marks black rounded, | tions
Dorsal
hump not

nipple-like

Limnophilide with gills arising in tufts of two or more. Without dark colored
longitudinal mark on frons.

SET4& ON CAUDAL HALF OF 1ST AB-
NAME COLOR PATTERN OF FRONS| DOMINAL SEGMENT, VENTRAL SIDE

Entirely light, except few} Scattered, not arising in two clusters

PLATYPHYLAX DESIGNATUS & !
brown spots behind middle of segment

CHILOSTIGMA DIFFICILE Uniformly brown Scattered, not arising in two clusters
behind middle of segment.

PLATYCENTROPUS MACULI-| Entirely black, except Gathered in two groups.
PENNIS caudal margin and few
brown spots

LIMNOPHILUS SUBMONILI-| Light, except caudal mar-| Scattered, not arising in two clusters
FER gin and sparse brown behind middle of segment.
mottlings.

42

LIMNOPHILID&E.

GLYPHOTALIUS HOSTILIS.

Hasrrat.—Full-grown larve were not uncommon during the
fall of 1919 in the cove and pools about the Field Station. During
previous summers a few larve were taken in the same locality, but

GLYPHOTAELIUS HOSTILIS.

47. Larva. Head and thorax. 49. Larva. Frons.

48. Larva. Distribution of gills. 50. Case of larva.
never in sufficient quantities to work out the life history of the
species. In the summer of 1919 the larve were found in great
numbers in the ditches of the Swamp at North Spencer. Hitherto
the species has never been recorded from New York State.

Hapits.—The larve were found climbing on submerged vege-
tation and crawling over the bottom, together with Phrygane ves-
tita and P. interrupta. Nothing is known of the larve during the
first instars.

Periop oF EMERGING.—A single specimen emerged in the
laboratory on April 5.

DeEscRIPTION OF Larva.—Length. 30—35 mm.; breadth, 5
mm. In life the soft parts are green and the chitinous parts are
pale-yellow and dark-brown or black.

The Head—A black band commences at the base of each
mandible, and, touching the upper margin of the eye, curved inward

43

NORTH AMERICAN CADDIS-FLY LARVZE.

to the point of the frons, where the two meet (figure 47) ; a black
band encircles the hind margin of the head; the frons is marked
with a longitudinal stripe (figure 49), and is margined in front
with brown; the mandibles are black; otherwise the head is straw-
yellow.

The Thorax.—The prothorax is completely margined with
black, except a narrow space at the base of each coxa; there is a
dark-brown mark in the shallow transverse furrow, and an ill-
defined brown area in front of the black caudal margin; otherwise
the prothorax is pale yellow. The dorsal plate of the mesothorax
is pale yellow, more or less mottled with brown, and with a border
of dark-brown or black; in some specimens a curved black line
crosses each caudal corner of the plate. On the metathorax the
chitinous plates are dark-brown, more or less nearly surrounded
by a lighter border.

The Abdomen.—On the first segment the spacing-humps are
well developed; a few sete arise from a small dark spot on each
side of the cephalic margin of the dorsal hump; on the ventral
surface there is a mound-like elevation bearing a pair of chitinous
spots from which several sete arise ; on the ventral surface of each
segment, three to seven, there is an oval chitinous disc, and on the
eighth segment there is a pair of smaller discs; the gills are unusu-
ally broad and long, from one to three or four filaments arising
from a single stem, but the number of filaments, and even the
number of gills, is subject to very great variation in this species;
figure 48 diagrams the distribution of gills for an average speci-
men.

DEscRIPTION OF THE Case.—In length the cases of mature
larve are from 3.5 mm. to 5 mm. They are made of irregularly-
shaped sections of leaves, as shown in figure 50; at the caudal end
of the case the ends of the leaves are drawn abruptly in, leaving
a round hole considerably smaller than the diameter of the tube.

LIMNOPHILUS COMBINATUS.

Hasrrat.—The larve are common in the slow-moving streams
of Michigan Hollow, McLean marshes, and other upland localities.

Hazits.—During their early life the larve frequent the grass
and sedges which fringe the edges of the streams. As the time for
pupation draws near they wander from the edges where marsh

44

LIMNOPHILID&. —

grass abounds, to the middle of the stream where living vegetation
is entirely absent. Here they attach the front ends of their cases
firmly to some solid support, as a stick or stone. Often many of
these pupe are found congregated on a single small stick, while
on the other sticks in the region they are entirely absent.

Foop or THE Larva:.—The food consists, apparently, entirely
of vegetable matter. Several stomachs from specimens taken at
different periods of late spring and early summer were examined.
These contained only the tissue of higher plants, but it seems prob-
able that during the cold weather, when diatoms abound, these
may compose a considerable portion of the diet of this species.

Prrtop oF EMERGING.—This species is one of a few Trichop-
tera known to us which emerge during a long period. On May 22
there were pupe in the stream, but no empty cases were found.
On June 7 the first specimens in captivity emerged, but at that
time there were many empty cases in the stream. From June 7
until July 22, when the last captive specimen emerged, their trans-
formations in the cages were of almost daily occurrence. On the
latter date, however, there were still many pupz in the stream, and
also a few prepupe. From this data we may assume that the
species is on the wing from early June until the middle of August.

DescripTIoN oF Larva.—Length, when mature, 17—20 mm. ;
breadth, about 4.5 mm.

Head.—The dorsal markings are shown in figure 51; on the
sides the head is light-brown mottled with dark-brown or black
in the region behind the eye; the venter is light-brown in front,
becoming darker toward the hind margin. The labrum is shown
in figure 53; the frons in figure 55, and the labium and maxille,
in part, in figure 54.

The Thorax.—The dorsal markings are shown in figure 51;
on the sides, above each coxa, there is a dark chitinous plate bear-
ing a group of sete near its front margin; the venter is uniform
in color. The “horn” on the ventral side of the prothorax is slen-
der and evenly curved forward. The legs are dark-brown, mar-
gined and mottled with dark-brown and black.

The Abdomen.—The first segment is darker in color than the
succeeding segments ; it is armed with a few sete in the region of
the humps and on its ventral surface; segments two to seven bear

45

NORTH AMERICAN CADDIS-FLY LARVZ.

a few minute setz ; segment eight is bordered along its hind dorsal
region by a dark area which bears a row of about six sete; seg-
ment nine curves sharply downward and is darker in color than
segments two to eight; it bears a dorsal chitinous plate which is

LIMNOPHILUS COMBINATUS.

51. Larva. Head and thorax. 56. Case.

52. Case. 57. Larva. Distribution of gills.

53. Larva. Labrum. 58. Pupa. Chitinous plates of left
54. Larva. Lower mouthparts. side of abdomen.

55. Larva. Frons.

armed with four large and several smaller sete; there are also
several strong setz in the region of the drag-hooks; on the under
side of each segment, two to seven, there is a narrow hair-like
mark, oval in shape; the lateral fringe is short and black. The
distribution and number of gills on the left side of the body
are indicated diagrammatically in figure 57.

DESCRIPTION OF THE Pupa.—tlLength, 20—22 mm.; breadth,
about 5 mm. The antenne extend back to about the hind margin
of the seventh segment; on the dorsal surface of the head, between
the antennz, there is a pair of strong sete, and on the front sur-
face, midway between the dorsal sete and the labrum, there is a
pair of similar sete ; each lobe of the labrum bears a group of stout

46

LIMNOPHILIDZ.

setee which are curved, but not hooked, at their tips. On the sec-
ond and third pairs of legs the swimming hairs are well developed.
The lateral fringe is thick and black; the projections of the last
segment are much as in L. indivisus (figure 64). The dorsal sur-
face of the first abdominal segment and the chitinous plates (the
latter subject to variation in the number of teeth) are shown (left
side only) in figure 58.

THE Case.—Length, 20—25 mm.; the breadth varies greatly
according to the material used in construction. The young larve,
before they leave the grass on the stream’s edge, make a case of the
cross-stick type common in this genus. When, as the time for
pupation draws near, they migrate away from the grassy area,
their cases take on an entirely different appearance, being con-
structed of shells, or small chunks of bark, or seeds, from the bot-
tom. In the meadow area at Michigan Hollow the building ma-
terial used, after their migration from the shore line, consisted
almost entirely of the shells of water snails—Planorbis and Sphe-
rium, for the most part—and of oval seeds. Figure 56 shows a
case from this area. Higher up in the same stream, where the
waters are overhung with thickets, the larve use chunks of bark
in the construction of their cases (figure 52). Different combina-
_tions of these materials are frequently found, and sometimes cases
are encountered in which the front part is made of shells or
chunks, while the hind part retains the cross-stick construction
used in its previous environment.

LIMNOPHILUS INDIVISUS.

Hasitat.—Upland pools or ponds which are rich in decaying
vegetation and are subject to desiccation during the middle or lat-
ter part of summer.

In waters which it inhabits this species is found in extraordi-
nary numbers, its cases almost covering the bottom of the pond
during the late larval period.

Hasits.—During the period when water covers their habitat
the larve can be found clumsily drawing their bulky cases over the
bottom of the pond or climbing over the vegetation. Their activ-
ity, apparently, does not cease during the winter months.

Early in May, close examination of a pond where the larve
had been found in great abundance, covering the bottom with an

47

NORTH AMERICAN CADDIS-FLY LARVZE.

almost unbroken mass of moving cases, at first revealed not one
inhabited larval or pupal case. They were not on the bottom, nor
were they clinging to the vegetation, as is the habit of some species
of the genus when pupating, nor were they under sticks or logs,
nor in crevices. At last they were found deep down among the
fibrous roots of sedge tussocks. Here they occurred in such num-
bers that they could be brought out by the handful from every
tussock. Well hidden, as they were, their hiding places had been
found by the muskrats of the region. Stumps and floating logs
were piled by the rats with broken pupal cases from which the
contents had been removed. Muskrat feces taken from these lo-
cations and disintegrated in water revealed enough chitinous frag-
ments to indicate that the caddis-pupe were an important article
of diet at this season.

On emerging, the pupze come to the surface and swim about,
apparently blindly, until they encounter some suitable support pro-
jecting above the water, where, climbing a few inches above the
surface, they transform. The greatest number of adults were on
the wing during the middle of May. At this time swarms of them
clung to every near-by bush, or, as dusk changed to darkness, flew
over the pond.

Foop oF THE LArva#.—The larve eat vegetable matter, living
or dead, with little discrimination for species or condition of pres-
ervation. ‘They may readily be seen browsing on dead and de-
caying cat-tail or sedge, or on living plant tissue, or scraping loose
fibers from submerged sticks. The stomachs examined contained
particles of higher plant tissue in all stages of preservation, as well
as many alge, but decaying tissue was always in greatest abun-
dance. The dominance of decaying tissue in the stomachs may be
explained by a glance at their habitat during spring, before the
period of pupation. At this time the pools are full of dead and
decaying cat-tails and sedges; living plants are relatively rare.
The alge are apparently swallowed accidentally with the larger
plants over which, in these pools, they form a thick scum.

DESCRIPTION OF THE LArvA.—Length, when mature, 18—21
mm.; breadth, 3.5—4.5 mm. The color of the heavily chitinized
parts is brown; the abdomen and weakly chitinized parts are white
in young specimens, and rusty brown in individuals that are almost
ready to pupate. The rust-like appearance of the weakly chitinized

48

LIMNOPHILIDZ.

parts of this larva is caused by a coating which can, with difficulty,
be removed, leaving the skin white and revealing a sparse armature
of very minute spines. The distribution of this rust-like coating

Zar e

LIMNOPHILUS INDIVISUS.

59. Larva. Head and thorax. 63. Larva. Labrum.
60. Larva. Distribution of gills. 64. Pupa. Caudal appendage.
61. Sievenet. Front end of pupal 65. Larva. Frons.

case. 66. Pupa. Chitinous plates of left
62. Sieve net. Caudal end of pupal side of abdomen.
case.

is nearly uniform in different individuals and seems to be a secre-
tion from the skin.

Head.—Marked above as in figure 59; the sides are light-brown
without sharply defined marks, but, on caudal portion, bearing
many small, inconspicuous muscle-attachment spots; the ventral
side is uniformly light-brown, except the extreme caudal portion,
which is crossed by the area of dark spots extending downward
from the sides; the antennez are jet black, except an area at the
base, which is brown; the labrum (figure 63), is light-brown bor-
dered with dark-brown ; the mandibles are jet black, truncate, with
fine teeth and a rather sparse brush of light-colored hairs on the
edge of the groove; of these hairs the most cephalic are shorter
and thicker.

4 49

NORTH AMERICAN CADDIS-FLY LARVE.

Thorax.—The dorsal markings are shown in figure 59. The
prothorax bears minute forward-pointing spines on its cephalic
dorsal margin; its sete are long, some equal to the length of the
segment; a raised, black collar-like ridge extends from the base
of the legs over the dorsum of the caudal margin of the segment,
except at the median area, where it is broken; the ventral surface
is white, except a brown spot which bears two darker marks near
its caudal margin, and a small darker spot behind each leg; the
fleshy horn is curved and well developed. The mesothorax is white
beneath, with four dark spots near the caudal margin. The meta-
thorax is white on the under side, with two broken dark marks.

Legs.—Brown, with darker margins, and armed with numer-
ous long black sete.

Abdomen.—The humps are well developed; the dorsal hump
bears a pointed, finger-like process, and the lateral humps are
rounded; groups of sete occur at the sides of the humps; about
six large sete and several small ones occur on the ventral surface
of the first segment ; other segments do not bear large setze on their
ventral surfaces; segments 2 to 7 bear single small sete on each
side of the medium line above; segment 8 bears a row of about
ten sete across its ventral surface ; segment 9 has an oval chitinous
plate on the dorsum, which bears four large and many small sete ;
each drag-hook has three small teeth at its base and is preceded by
a chitinous plate bearing about ten set; a row of three large sete
occurs inside of each drag-hook and behind the chitinous plate;
the lateral fringe is black and well developed ; it extends from near
the cephalic margin of segment 3 to the caudal margin of seg-
ment 8; above the lateral fringe on each segment occur minute,
brown, paired spine-like processes; the gills are well developed ;
their number and distribution are shown diagrammatically in
figure 60. The weakly chitinized portions of the entire larva are
thickly set with minute spines.

DESCRIPTION OF THE Pupa.—Length, 13—17 mm.; breadth,
4—4.5 mm. In life the color of the thorax and appendages is
brown, the abdomen is green, and the lateral fringe is deep black.
The antennz extend back to about the caudal margin of the eighth
segment; they bear groups of short setz on the dorsal sides of
the second segments; each side of the labrum bears a group of
about six long, hooked sete; a row of sharp, curved forward-

50

LIMNOPHILID&.

pointing spines borders the caudal margin of the eye; the second
and third pairs-of legs have well-developed swimming hairs and,
in advanced pupz, show the black spines of the adult conspicuously ;
the lateral fringe is well developed, commencing on the caudal
margin of segment 5 and turning under the abdomen at the caudal
margin of segment 8; the gills are well developed ; the last segment
bears a number of sete and two backward-pointing processes
(figure 64).

DESCRIPTION OF THE CasE.—The length and breadth vary ac-
cording to the material found in its environment. It is always
bulky and is usually of the cross-stick type common in the genus.
It may be made of bits of leaves or plant-stems or, sometimes, of
seeds. When seeds are used it does not show the tendency to cross
the material. The cavity is cylindrical and is always lined from
end to end with a sheet of silk.

The case of the pupa differs from the larval case only in hav-
ing the mesh of silk across its ends as illustrated in figures 61, 62.

LIMNOPHILUS SUBMONILIFER.

Hasitat.—The larve are found in shallow water where there
is an abundance of vegetation, often in situations that are com-

LIMNOPHILUS SUBMONILIFER.

67. Larva. Head and thorax. 69. Case of mature larva.
68. Larva. Frons. 70, Case of immature larva.

51

NORTH AMERICAN CADDIS-FLY LARVE.

pletely dry during the droughts of summer. In the shallow edges
of the Cove, in Bools’ Backwater, and in most similar situations of
the region, they are not uncommon dwellers.

Hasrrs.—Members of the species are bottom-crawlers, where
their cases, closely resembling stems and grasses, are detected with
no little difficulty.

Before pupating the larvae wrap themselves securely, including
their cases, in folds of the leaves of submerged plants or grasses.
In this condition they are so perfectly concealed that their de-
tection requires careful examination of every grass-blade.

Foop or LArva:.—Raspings from submerged sticks and plants
form the food of the larve. In the raspings are found diatoms
and other microscopic organisms, as well as wood and plant frag-
ments.

If one watches a larva feeding upon a diatom-covered stick he
will plainly see a trail of clean wood left behind the slowly moving
larva.

DESCRIPTION OF THE Larva:.—Length, 15 mm.; breadth, 2.5
mm. The chitinous parts are light-brown, with a darker pattern
of slight contrast, as shown in figure 67. Details of marking are
subject to some variation in different specimens, but there is
enough uniformity of pattern to make color characters of value in
classification.

Head.—An ill-defined area of brown begins at the base of each
mandible and extends back, adjacent or close to the margin of the
frons and above the eye, to the caudal margin of the head; when
this mark does not touch the frons, the area between it and the
frons is almost colorless ; each eye is located on the upper cephalic
side of a light-colored circle ; behind the eye the entire head is more
or less marked with muscle-attachment spots; in front of this area
the under surface is uniform brown. The frons (figure 68) is
brown, with a light mark of varying size extending back from the
median part of the cephalic margin, and a light-colored area be-
hind the muscle-attachments spots ; in some specimens the margins
behind the constrictions are light-colored; the muscle-attachment
spots are dark, but not strongly contrasting in color.

Thorax.—The prothorax is light-brown, margined with dark-
brown or black, and with varying marks of brown (figure 67).

52

LIMNOPHILID&.

On the mesothorax the chitinous shield is pale-brown, with darker
markings and black caudal margin terminating laterally in ex-
panded black marks of varying extent; a broken dark mark is some-
times present on the cephalic margin. The chitinous plates of the
metathorax are pale in color; the lateral plates are crossed by two
dark marks.

The Abdomen.—On the ventral surface of the first segment
there are a few weak setz, which are not arranged in clusters. The
gills are weak and are branched into a few weak filaments.

DESCRIPTION OF THE CasE.—The case of the larva has the
form of a cylinder about twenty millimeters long and four milli-
meters wide. It is made of vegetable matter of various kinds, ac-
cording to the environment inhabited by the larva.

A common type of case is made of fragments of bark (figure
69). These cases generally curve slightly and taper toward the
caudal end. The cephalic end is without a hood; the sides of the
caudal end are drawn in to leave a small round opening.

When the larve live among cat-tails, or where large fragments
are used, the curve of the case is less apparent, or may be entirely
absent. Likewise the caudal end is less closed, or may be entirely
open.

When living among roots, the larve often fasten root fibers
along the sides of their cases (figure 70).

In preparing to pupate the larve roll their cases in dead leaves,
or in grasses. At such times they are next to impossible to dis-
cover.

ARCTECIA CONSOCIA.

LarvaL Hasirat,—tThe larve occur locally in most streams
of the region. They are more common in shallow water with a
slight current, but they are also found in deep waters that are cool
and well aeriated.

Hasits.—In their manner of living the larve do not differ
greatly from Pycnopsyche and its near allies, and, like them, the
habit of changing the architecture and material of their cases from
one type to another is frequently practiced. When time for pupa-
tion approaches, the larve usually hunt the seclusion of matted
roots along the water’s edge, or crevices in submerged logs or bark.

On one occasion several pupze were found attached to roots

53

NORTH AMERICAN CADDIS-FLY LARV.

two to four inches above the level of the water. The water below
was a spring pool which never rises to the level to which the larve
had climbed. These pupe were put in cages with no water, and
successfully emerged about ten days later.

Foop oF Larvai.—The larve feed on shallow raspings from
the sticks and vegetation of the waters they inhabit. Stomachs
examined contained a large amount of the outermost tissues of
plants and sticks, together with about the same amount of sessile
diatoms, and an occasional fragment of some minute crustacean,
perhaps swallowed by accident.

PERIOD OF EMERGENCE.—Specimens in captivity emerged dur-
ing the latter part of June.

DescrIPTION oF LAarvA.—Length, 25 mm.; breadth, 4mm. In
attitude the larve maintain straight abdomens, slightly curved
thorax, and head turned well under the first thoracic segment,
with the mouth parts between the front legs. The coxe are carried
with their distal ends directed toward the median line of the body,
which brings the bases of the tibiz almost together.

The Head.—In color the head (figure 71) is light-brown, with
very faint speckles of a shade darker over the dorsal and caudal
portions ; an unspotted area begins at the hind margins of the eyes
and extends around the caudal portion of the ventral surface of
the head. The sete on the dorsal surface are deep-black. The
frons is without pattern, except the faintly darker muscle-attach-
ment spots. The mouth parts are often carried almost entirely tele-
scoped within the cavity of the head; they have the general color
of the head, except the mandibles, which are deep-black; in form
the mandibles are broad and scoop-like, but slightly indented on
the anterior margin.

The Thorax.—The prothorax has the dorsal furrow very
feebly developed. In color the dorsal surface is pale straw-yellow
with a few inconspicuous small specks of a slightly darker shade.
The chitinous plate of the mesothorax is colored like the dorsal
surface of the prothorax, its narrow caudal margin is conspicu-
ously black, and there is a small, roughly triangular spot of black
near each lateral margin, about midway between the front and
hind margins. The deep-black coloring of the pleural suture is
limited to a spot near the base of the coxa, and does not extend

54

LIMNOPHILID&.

ARCTOECIA CONSOCIA.

71. Larva. Head and thorax. 75. Case. Cross section.

72. Case. 76. Larva. Distribution of gills,
73. Larva. Frons. 77. Case.

74. Larva. Mandible. 78. Case.

55

NORTH AMERICAN CADDIS-FLY LARVZ.

back in a narrow line. On the metathorax the median chitinous
plates are almost contiguous; the lateral plates are somewhat cre-
centric in form, and have a sparse growth of black sete near the
cephalic end.

The Abdomen.—On the first segment the dorsal hump is lack-
ing; the lateral humps are well developed. The dorsal surface of
the segment has a sparse growth of black setee, which are not ar-
ranged in groups; the ventral surface of the segment bears a pair
of light-colored chitinous plates, one each side of the median line
behind the middle of the segment, each plate bearing a sparse line
of short, dark-colored sete along its cephalic margin; in front of
these plates the cuticula bears a few irregularly placed sete; at
the base of each lateral hump, on the ventral side there is a pair
of pale chitinous plates, the caudal plate the larger, each bearing
a few sete. The distribution of gills is represented in figure 76.

DescCRIPTION OF THE CAseE.—The species makes such a great
variety of cases, of which different types so closely resemble the
cases made by several other genera, that it is impossible to place
any taxonomic importance on their architecture.

In a rough way the cases fall into two types—circular and
triangular in cross section.

The triangular cases, made like the caudal part of figure 78,
show the most distinct plan of architecture. From the exterior
three sides are visible; each side is slightly convex, and is made
of from three to six roughly oval sections of dead leaves. The
cephalic end of each oval is fastened under the caudal end of the
preceding oval. In cross section, figure 75, it is apparent that the
outer triangle surrounds a thin-walled cylinder of leaf fragments,
lined with silk.

In the cylinder type of case the larvee sometimes make very
neat structures of flat chips of stones, figure 72. In these cases
the stone chips are neatly fitted and cemented together with a thin
lining of silk. In cross section the cases are as nearly cylindrical
as the size of the stones will permit. Besides these cases, which
are built with a high degree of neatness, the larvae sometimes make
cases of twigs, fragments of bark, and debris of all sorts. These
cases, of which figure 77 represents one of the most perfect, are
among the most slovenly and carelessly-built cases inhabited by
Limnophilade.

56

LIMNOPHILID&.

ASTENOPHYLAX ARGUS.

Hasitat.—In most of the slow-moving, alder-bordered
streams of the uplands the species is uncommon, but in Michigan
Stream to the South, and Argus and Spherium Streams to the
East, they occur in the greatest abundance. In Michigan Stream
their numbers are astonishing for a species of such size. Many
hundreds of individuals live on a single rod of the small creek’s
bottom, and scores of pupz can often be found clinging to a
single root or stick.

Hasits.—As might be expected under the uniform conditions
of the spring-fed upland streams, the larve alter their habits but
little during the changing seasons. In winter, as in summer, they
crawl actively over the bottom, feeding and carrying on their
usual activities. In both seasons the stomachs are equally gorged.

By the middle of April the larve have ceased their activities
and have gathered and attached to their cases bulky, heavy mate-
rial, large pebbles, chunks of bark, the large species of Spheriide,
Spherium simile, or twigs, sometimes inhabited by the wood-bor-
ing Trichoptera of the genus Ganonema. ‘These heavy cases are
attached firmly by their cephalic ends to submerged logs, roots, or
other solid supports. At this time the sieve-nets are spun. In
Astenophylax argus the sieves are located within the tube a short
distance from its caudal and cephalic ends. The mesh varies in
size and form, but is roughly hexagonal.

Foop oF THE Larvai—The food of the larva throughout the
year consists of dead bark and wood rasped from submerged
twigs and logs. Specimens collected in February contained the
same kind of food as specimens collected in mid-summer, and
at both seasons the alimentary tracts were equally gorged.

Periop oF Emercinc.—The time of emerging is confined to
the first two weeks of June.

DEscRIPTION OF THE Larva.—Length of the mature larva is
50 mm. Its breadth at the third thoracic segment is 6 mm.

Head.—The head, except the mandibles, which are black, is
brown, with inconspicuous darker markings, which vary some-
what in intensity in different individuals, but maintain the same
general pattern for the species; the color-pattern and distribution

57

NORTH AMERICAN CADDIS-FLY LARVE.

of setae on the dorsum are shown in figure 79; the underside of
the head lacks markings except an area of small, somewhat oval,
well-defined spots, which project forward from its caudal margin
on each side of the median line.

ASTENOPHYLAX ARGUS.

79. Larva. Head and thorax. 84. Larva. Labrum.
80. Larva. Frons. 85. Pupa. Mandible, outer edge.
81. Pupa. Mandible, lateral view. 86. Larva. Lower mouthparts.
82. Larva. Distribution of gills. 87. Case.
83. Pupa. Chitinous plates of left

side of abdomen.

Thorax.—The color-pattern of the dorsum of the first and
second segments is shown in figure 79; the under side is weakly
chitinized, except for the horn on the first segment; the third seg-
ment above is weakly chitinized, except for a median glabrous
spot near the cephalic margin, on each side of which there is a
dark-brown mark, bearing five or six sete; farther back and
slightly more remote from the median line there is a triangular
spot bearing about ten sete; on each side of the segment there is
an elongate glabrous area marked with several brown spots, the
cephalic of which bears about a dozen sete; the second and third
thoracic segments bear numerous minute spines which, for the
most part, point forward.

58

LIMNOPHILID&.

Legs——Brown, with darker markings along the edges and
around the sete.

Abdomen.—The first segment above has several circular brown
spots surrounding sete, a glabrous area borders the caudal margin
of each lateral hump, and a group of four or five fine sete is
present above and below each lateral hump; on the ventral side
there are a few scattering sete and a bilobed median mark, con-
taining four or five sete in each lobe; the entire surface of the
first segment is thickly set with very minute spines. The lateral
fringe of black hair begins near the posterior margin of the
second segment and extends to the posterior margin of the eighth
segment. The arrangement of gills is diagrammatically shown in
figure 82. A slight variation of gills occurs on the caudal seg-
ments of different individuals.

DESCRIPTION OF THE Pupa.—Length, 30 mm.; breadth, 6 mm.
The labrum is longer than broad, extending shelf-like over the
mandibles and bearing a group of five long, dark-colored, hooked
sete on each side; two similar sete, but not hooked occur on each
side near the base, a shorter seta of lighter color points forward
from the cephalic margin of each lobe and a similar seta occurs
laterad from each pair of long basal sete; the mandibles are
straight, without teeth and sharply pointed, reaching not quite to
the extreme of the labrum; each bears two sete near its base; the
dorsal part of the first abdominal segment is marked with small
cross-folds, which give it a striate appearance, and is bordered
behind with wing-shaped marks, somewhat striate and bearing
numerous small thorns on their caudal margin, figure 83 ; the lateral
fringe is black, commencing near the caudal margin of the fifth
abdominal segment and forming a loop beneath the caudal margin
of the eighth segment. The antennz reach to the caudal margin
of the sixth segment. The chitinous plates are shown in figure 83,
but the number and arrangement of teeth is subject to variation in
different individuals.

DESCRIPTION OF THE CAsE.—The larval cases, figure 87, the
largest and most bulky in our streams, are constructed of frag-
ments of twigs and bark, which vary greatly in size and shape.
These fragments, arranged with little regard for system or sym-
metry, are fastened securely together by means of silk, and the

59

NORTH AMERICAN CADDIS-FLY LARVE.

tube thus formed is lined from end to end with a tough cylinder
of silk. Clumsy and bulky as the larval cases are, they do not
vary greatly from cylindric form, nor do they have projecting
twigs or corners that would catch during locomotion, nor chunks
or stones that would be too heavy for the powerful larve to drag.
In the pupal cases heavy stones and great fragments of bark are
used, whose weight and form would make locomotion almost im-
possible.

PYCNOPSYCHE SCABRIPENNIS.

HasitaT.—Specimens of this species were collected only in
Spherium and Argus Brooks; but the larva and cases are so sim-
ilar to Halesus, and probably to other genera, that it is by no
means probable that its distribution is as restricted as our data
would indicate.

Hasits.—In the streams mentioned the larve are exceedingly
abundant, crawling slowly over the bottom, or clinging with their
heads pointing upstream, to submerged sticks and logs. In the
latter position they sometimes completely cover sticks which are
slightly above the stream’s bottom, but upon the slightest jar they
relinquish their holds and float down with the current.

Before pupation the larve leave the open water and hunt the
seclusion of crevices in bark or root mats. At this time casual
examination of the stream reveals not one larva in localities in
which thousands previously formed the most conspicuous life on
the bottom.

Foop or Larva:.—Stomachs examined contained only raspings
of decomposed wood, much of which was ground to fine powder.

Prriop oF EmMERcING.—Adults appear during the last days of
August and the first part of September.

DescripTION oF Larva:.—Length, 25 mm.; breadth, 3.5 mm.
Head.—The head, figure 88, is large; in dorsal view it has
almost parallel sides, slightly curved caudal margin and almost
straight cephalic margin; in color it is straw-yellow, with a vary-
ing pattern of round or oval muscle-attachment marks, and shad-
ings of dark-brown; on the ventral surface the brown muscle-
attachment marks are confined to the caudal half of the head and
60

LIMNOPHILIDE.

are bounded on each side in front by an oblique line of black mus-
cle-attachment marks ; between the oblique line of black attachment
marks and the mouth parts there is shading of black and brown.

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PYCNOPSYCHE SCABRIPENNIS.

88. Larva. Head and thorax. 92. Case.
89. Case. Cross section. 93. Case.
go. Larva. Distribution of gills. 94. Case.
gi. Larva. Frons. gs.. Case.

61

NORTH AMERICAN CADDIS-FLY LARVZ.

The labrum is small, and about half the breadth of the cephalic
margin of the frons.

Thorax. —The prothorax, figure 88, on its dorsal surface, has
ground color of straw-yellow, slightly lighter than the head; it
is shaded and mottled with dark-brown.

On the mesothorax the dorsal chitinous plates are mottled
with dark-brown, except a circular area in each outer caudal
angle, which is without mottling.

The metathorax has the median plates slightly separated, sit-
uated on a single plate-like area that is apparently more heavily
chitinous than the surrounding integument of the segment. The
plates of the second pair are uniform brown. The lateral plates
are brown with dark marks at each end.

Abdomen.—On the first segment the spacing-humps appear
as flat, brown, callous areas, which are but slightly raised above
the surface of the segment; the cone-like form of the humps of
Halesus is entirely absent. On the ventral surface, behind the
middle of the segment, there is a pair of chitinous plates, each
bearing about six sete; in front of the middle of the segment
there are a few scattered sete.

The arrangement of gills is shown in figure go.

DESCRIPTION OF THE CaseE.—The cases of Pycnopsyche
scabripennis are subject to great variation in form. As a rule,
the variation is seasonal—almost all of the cases are made on the
same plan and undergo the same transitional change at the same
time, but there are often a few specimens to be found that have
omitted certain changes in their case-making. So one finds great
numbers of specimens in a locality making cases of the same
kind, but with careful search it may be possible to find examples
of other types of architecture.

The first cases made by the species are usually flat, two-sided
cases of leaf fragments, figure 93. In making this form of case
the larva cuts round or oval fragments from sunken leaves. These
pieces are cemented on the opposite sides of the cylinder in which
the larva lives. At the cephalic end the upper leaf, or root, pro-
jects, hood-like, beyond the end of the tube; at the caudal end
the roof covers the end of the tube, but the floor usually projects
out even farther. Between the roof and the floor lies the tube in
which the larva lives. It is made by cementing sides of small

62

_LIMNOPHILID.

leaf fragments between the broad floor and roof, and lining the
cavity thus formed with a thin but tough sheet of silk. Figure 89
represents a cross-section of the case.

This type of case is used during the winter and spring months.
It is the type most frequently omitted by the larve, perhaps be-
cause their environment does not always furnish suitable material.

Though the broad, flat form of these cases of leaf fragments,
with their hoods projecting over the heads of the slowly-crawling
larve, are as nearly invisible as is possible, it seems probable that
their most important function is to form a broad surface that will
always remain with the same side up, and not roll in the slow
current.

As the larve get older, in late spring, they change the flat-leaf
type of case to cases in which the tube is much tougher. Small
fragments of bark are now mixed with pieces of leaves in the
tube, the broad roof and floor of leaves is discontinued, and on
each side of the case a heavy stick is added, which usually runs
the entire length of the case and projects for half an inch beyond
each end, figure 94. These “ballast” sticks have the same function
as the flat surface of, the leaf cases—they keep the cases from
rolling in the current.

In changing the case from the flat-leaf type to the ballast-stick
type, the sticks are added to the top and bottom of the leaf case,
causing the sides of the leaf case to become the top and bottom
of the ballast-stick case. Figures 92 and 94 represent the transi-
tion between the flatleaf case and the ballast-stick case.

When the time for pupation draws near the larve of Pycnop-
syche, like several other species that use ballast sticks, cut away
the ballasts and make rough cases of irregular construction, in
which there is no difference between top and bottom, figure 95.
When the case is made fast for pupation there is no longer need
to make other provision against its rolling in the current.

PLATYPHYLAX DESIGNATA.

Hasirat.—The larve are abundant in the Big Springs of the
McLean basin, and occur in less abundance in several of the near-
by springs and spring streams. All of the waters in which the
larve have been found are cold throughout the summer and never
freeze in winter. It was in similar springs in Wisconsin that
Vorhies first found the larve.

63

NORTH AMERICAN CADDIS-FLY LARV.

Although, in the Cayuga Basin, the larvee have been found only
in the McLean region, careful collecting probably will reveal their
presence elsewhere, for the adults are not uncommon in several
localities of our uplands.

Hasits.—During the daytime some larve can always be
found crawling over the bare stones of the springs they inhabit.
More larve, however, are to be found attached to the under-side
of sticks and stones. These larve, like other species of Limno-
philidz, are nocturnal, except, perhaps, when newly hatched from
the egg. On this subject Vorhies, ’05, makes the following in-
teresting observation: ‘The interesting fact was noticed that
these newly-hatched larve are positively heliotropic to a marked
degree when on a dry surface, but at once become negatively helio-
tropic when placed in a dish of water. The necessity of getting
out from beneath stones where the eggs are placed in order to
find water, and of getting beneath stones for protection while
building a case, after reaching it, offers an explanation for this
peculiarity.”

In preparing to pupate, unlike the common method of the
family, the cases of this species are not attached to any object, but
lie on the bottom of the stream, sometimes under stones and sticks,
sometimes on the surface of the gravel, but always with the head
directed upstream. In one habitat of the species the bottom is of
rather soft muck. In this spring the pupal cases were always
buried under an inch or more of soil.

Prepupe and pupe can be found in every season of the year,
unless, possibly, the early months of winter. Their greatest
abundance, however, comes during late winter and very early
spring.

Foop or Larva:.—To determine the food of the larve, about
six stomachs of mature larve, and as many of young larve, were
examined. The stomachs of the young larve contained only
diatoms, mixed with a large amount of sand—the sand amounting
to many times the bulk of the diatoms. The stomachs of the old
larve contained about the same mixture of sand and diatoms, and
also a few fragments of higher plants. Vorhies, ’05, found the
food of the old larve consisting of water-cress and water-mil-
foil, and in 1909 states that the young larve feed upon diatoms.
In the springs of the McLean region there is a very sparse growth

LIMNOPHILID&.

of higher plants, which probably forces the larve to feed upon
diatoms throughout their lives.

Periop oF EMERGING.—The species is on the wing in greatest
numbers about the middle or latter part of April, but late comers
have been found in our locality until the latter part of August,
and Vorhies, in Wisconsin, found several egg masses on October
12th, and one egg mass as late as November 2d. Our first speci-
mens were taken on bright days during the very first part of April,
when snow in nearby drifts was still piled to a depth of several
feet. At such times the adults are not uncommon.

In leaving the cases the pupz sometimes follow the usual
method of breaking through the end of the case. More often,
however, they tear out a section of the side wall, leaving a long,
jagged hole in the side of the case.

a

PLATYPHYLAX DESIGNATUS.

96. Larva. Head and thorax. 99. Larva. Frons.
97. End of pupal case. 100. Larva. Distribution of gills.
98. Larva. Gills. ror. Case.

DESCRIPTION OF THE LaRvA.—Length, 18 mm.; breadth, 4
mm. In life the body is light-green in color. In form it is dis-
tinctly curved, and apparently incapable of straightening.

5 65

NORTH AMERICAN CADDIS-FLY LARVZ.

The Head—Deep mahogany-brown; in some specimens so
dark that the pattern is visible only in the best illumination, figure
96. The pattern is very slightly darker than the ground color of
the head. On the frons, figure 99, the muscle-attachment spots
are the only marking, but the ground color gradually becomes
darker toward the mouth-parts. The head, in front of the eyes,
is without markings; behind the eyes, on the dorsal, ventral and
lateral surfaces, there is a mottling of small spots, slightly darker
than the ground color. Each eye is bordered on its lower side by
a crecentric mark of light color.

The Thorax.—The pronotum is of lighter color than the head ;
its pattern is shown in figure 96; on the under-surface there is a
median dark mark near the caudal margin ; the horn is dark-brown.
On the mesothorax the dorsal chitinous plate has the same ground
color as the pronotum. It is bordered along the hind margin by
a narrow line of deep black, which widens at the angle with the
lateral margin and extends about half way up the sides; on each
side of the chitinous plate, opposite the end of the black marginal
stripe, there is a small, deep, black mark, which sometimes blends
into the black marginal line; on each side of the median ventral
line, near the caudal margin of the segment, there is a curved line
of about five small round chitinous spots. On the dorsal surface
of the metathorax the median chitinous plates are separated by
about the breadth of one of the plates; the lateral plates are some-
what crecentric in form, with a sparse growth of sete on the
cephalic third ; behind these sete the plates are marked with black.

The Abdomen.—VYhe dorsal hump on the first segment is well
developed and pointed—the lateral humps are rounded; on the
ventral surface there is a broad, raised area covered with an
evenly-distributed growth of black sete. Each gill arises from
a single stem and branches biramously on a single plane, figure
98. The distribution of gills is diagrammed in figure 100.

DESCRIPTION OF THE CasE.—The typical case of the larva,
figure 101, is made in the form of a slightly-curved cylinder, taper-
ing gradually toward the caudal end. On the outside of the curve
of the cylinder, at the cephalic end, there is a tapering hood which
extends over the head of the larva, completely covering all but
the legs. These cases are made of grains of coarse sand of nearly
uniform size, and are lined with a tough, but brittle, sheet of silk.

66

LIMNOPHILID&.

In the habitat where the bottom is of muck the larvz use small
chips of bark in the structure of their cases, making them as
nearly the typical form as the nature of the material at hand will
allow.

The case of the pupa is like the case of the larva, except that
there are pebbles of large size grouped around and over the front
end of the case, giving it a rounded form. The opening at the
caudal end of the case is covered and rounded with pebbles of
about the same size as those of the larva’s case. At each end the
case is perforated through the silk lining between the pebbles, by
from one to six round holes, figure 97.

The pup cases from the mucky situation had many small
molluscs fastened to the cepahlic end.

HALESUS GUTTIFER.

Hasits.—Larve are common in Michigan Streams below the
swamp, and have been taken in Spencer Lake. It is probably a
common species in many of our ponds and slow-moving streams.

In habits the larva does not seem to differ from Pycnopsyche
scabripennis, but it has not been so well studied.

Before pupation the larve attach the cephalic end of the case
to the under-side of a submerged log, or within some crevice of
wood or bark.

Foop or LarvA.—Fine raspings of decomposed wood seem to
be the only food of the larve.

PERIoD OF EMERGING.—Specimens in captivity emerged dur-
ing August and September. Wild specimens have been taken on
the wing as late as November.

DEscriPTION oF Larva.—No constant characters have been
found that will distinguish between the larve of Pycnopsyche
scabripennis and Halesus guttifer, except the size and form of the
spacing humps. In H. guttifer the dorsal and lateral humps are
well developed; the dorsal hump is cone-like, terminating in an
acute nipple-like process.

The description of other parts of the larve of Pycnopsyche
scabripennis will apply equally well to Halesus guttifer.

DESCRIPTION OF THE CasE.—Halesus guttifer makes ballast-
stick cases and irregular prepupal cases, which are not distinguish-
67

NORTH AMERICAN CADDIS-FLY LARVZ.

able from those of Pycnopsyche scabripennis, figures 92, 94. The
species has not been observed during the early season to ascertain
whether it makes the flat-leaf type of case.

PLATYCENTROPUS MACULIPENNIS.

Hasirat.—The larve live in spring-fed streams, where the
water is clear and cold, and where the growth of vegetation is
sparse or wanting. In limited numbers they are found in parts
of Bool’s Brook, but in the streams of the McLean Basin, espe-
cially in Argus Brook and the upper regions of Spherium Stream,
they are among the most common caddis-worms.

Hasits.—The larve are bottom dwellers in streams with
gentle current, and without dense growth of vascular plants. In
such streams they are evenly distributed, apparently never con-
gregating in certain areas, as do the larve of many other species.

Before time for pupation the larve attach their cases to sub-
merged sticks or roots, or hide in the crevices of bark or wood.

Foop or Larva.—No studies have been made of the food of
the larve.

Pertop oF EMERGING.—Adults appear during the middle of
July.

Description oF Larva.—Length, 22 mm.; breadth, 4.5 mm.

Head.—The ground color is straw-yellow, shaded and spotted
with brown, as in figure 102; on the under-surface there is an
area of nearly round spots on the posterior part of each gena, in
front of the spotted area each gena bears a single elliptical coalesced
pair of muscle-attachment spots. Each mandible, figure 103,
bears a line of yellow hairs on the upper margin of the inner side.
The labrum has the straw-yellow ground color of the head, but
is margined with brown and has a brown spot near its center.

Thorax.—The prothorax, figure 102, is light-colored, profusely
spotted with brown. On the mesothorax the chitinous shield is
smoky-brown, with numerous dark spots, except an area near each
outer margin where the smoky appearance is absent; the black
caudal margin of the shield widens at the corners into a broader
mark, which has a constriction in the middle. The mesothorax;
on its dorsal surface, is creased by a well-marked furrow, which

68

LIMNOPHILIDZ.

passes around the median plates; the median plates are narrow
and are separated by not more than the length of a single plate.

Abdomen.—The spacing humps are flattened ; the dorsal hump
is surrounded by numerous scattered sete, which are not grouped
in clusters; on the ventral surface of the segment there is a lip-
like elevation of the cuticle, which bears a pair of large sete rising
from dark-colored punctures; in front of the folds the sete are
scattered over the ventral surface of the segment with no tendency
to form clusters; the distribution of gills is diagrammatically
shown in figure 104; each gill has, typically, three branches, ex-
cept on the last two or three gill-bearing segments, where the num-
ber of branches is reduced to one or two and the gills themselves
are weaker.

PLATYCENTROPUS MACULIPENNIS.

1o2. Larva. Head and thorax. 104. Larva. Distribution of gills.
103. Larva. Mandible. 105. Larva. Frons.

DEscRIPTION OF THE CasE.—Length, 20—25 mm.; breadth,
7—10 mm. The larve make cases of the typical cross-stick type,
selecting twigs or grasses of smaller diameter than is usual in the
genus Limnophilus, and cutting off the loose ends close to the
case, thus forming a case of more cylindrical and compact appear-
ance than is usual in this type of case.

At the caudal end of the case the walls are drawn abruptly
over, leaving a small circular opening to the tube.

69

NORTH AMERICAN CADDIS-FLY LARVE.

CHILOSTIGMA DIFFICILIS.

Hasitat.—The larve of the species have been found in a
very limited area of Argus Stream, in the McLean swamp. The
stream is a small one, hardly more than a foot in width and three
or four inches in depth. It rises in a sphagnum bog and penetrates
a dense thicket of alder for about a half mile, when it enters a
larger stream. Through the alder thicket the waters are in deep
shade, and leaves and sticks litter the bottom. In this portion of
the stream, so far as we can see, there are no differences of condi-
tions within its waters. Yet this species, for the three years we
have known it, has inhabited an area of the stream not more than
a hundred yards in length. In this limited area it occurs in great
numbers.

Hasirs.—Until the middle of summer is past these larve rest
or crawl slowly about over the bottom of the stream. As the
period for pupation approaches they congregate in great numbers
on submerged sticks or roots. Often they occupy every available
lodging space on a certain stick, while other similar sticks of the
neighborhood are left entirely free from their presence. Only
the front ends of the cases are attached to the support, from which
they project at all angles.

Foop or THE Larvai.—Stomachs examined contained quanti-
ties of fragments of wood and leaves, nothing else.

PERIop OF EMERGING.—Specimens in captivity emerged dur-
ing the first half of October, but it is probable that under natural
conditions they emerge throughout a longer period.

DESCRIPTION OF THE Larva.—Length, 16 mm.; breadth,
2.5—3 mm. ,
Head.—The color is light-brown, figure 106, almost uniform,
except the dark muscle-attachment circles and a thick stippling of
microscopic spots; the dorsal surface, especially the frons, figure
111, bears numerous pointed, spear-like processes, which are
plainly evident in balsam mounts. The labrum, figure 110, is
brown, with a darker mark behind the middle of its front margin;
the innermost sete on its front margin are short and blade-like ;
the outer sete of the front margin are longer, but blade-like; other
sete of the labrum are indicated by circles in the accompanying

70

LIMNOPHILIDE.

drawing. The mandibles are black, with a line of dense yellow
hair on the top edge of the groove:

Thorax.—The prothorax is light-brown with a slightly oblique
black mark on each side above the coxa; the top surface has, in

Sn nn Gann ed Gans Gn |

CHILOSTIGMA DIFFICILIS.

106. Larva. Head and thorax. 111. Larva. Frons,

107. Larva. Distribution of gills. 112. Larva. Front leg.

108. Pupa. Mandible. 113. Case.

109. Larva. Lower mouthparts. 114. Pupa. Chitinous plates of left
110. Larva. Labrum. side of abdomen.

addition to numerous sete of the ordinary type, many shorter,
spear-shaped, forward-pointing spines, not shown in the accom-
panying figure; these are most numerous along the front margin,
where they project over the base of the head; the dorsal markings
of the meso- and meta-thorax are shown in figure 106. The legs
are light-brown, margined and marked with black. Figure 112
shows a front leg.

The Abdomen.—The lateral fringe is short and weakly devel-

71

NORTH AMERICAN CADDIS-FLY LARVZ.

oped; it extends from the front margin of the third segment to the
hind margin of the eighth segment. The distribution of gills is
diagrammatically shown in figure 107.

DeEscRIPTION OF THE Pupa.—Length, 10o—11 mm.; breadth,
2—2.5 mm. The antenne extend back almost to the tip of the
abdomen. Each side of the upper surface of the labrum bears a
group of about five long, black, hooked sete. The mandible is
shown in figure 198. The lateral fringe begins near the hind
margin of segment five and curves under the hind margin of seg-
ment eight; it is black in color and is much better developed than
that of the larva.. The last segment bears a pair of fleshy ap-
pendages. The chitinous plates of one side of first and third-
seventh abdominal segments are shown in figure 114.

DESCRIPTION OF THE CasE.—The case of the larva, when ma-
ture, is 15—20 mm. long; its diameter is 4 mm. or more at the
cephalic end, according to the kind of material used in its con-
struction. In form it is cylindrical and slightly curved. The
larve, during their active period before pupation, construct their
cases largely of quartz sand, but usually have a greater or lesser
number of bark chunks around this inner cylinder. Sometimes,
however, these bark fragments are almost, or even entirely, lack-
ing. In preparation for pupation the larve usually remove almost
all of the plant fragments from their cases. They then congregate
in numbers on some support, as a submerged stick or root. Be-
fore pupation takes place the two openings of the case are stopped
with small grains of sand firmly cemented in place. Apparently
there is no mesh left open. Figure 113 represents a typical larval
case of quartz sand and a few fragments of bark.

GENUS NEOPHYLAX.

Head.—The head is very long and narrow, held pointing back-
ward with the under-side against the under-side of the thorax
when at rest.

Thorax. —The prothorax is narrow and lacks the “horn.”” On
the mesothorax the chitinous plates above the coxe extend back
until they meet the dorsal plates.

Abdomen.—A transverse elliptical ring marks the under-side
of segments three, four, and five.

72

LIMNOPHILID&.

The genus offers many unsolved problems, such as the func-
tion of the gill-like structures on the first abdominal segment in
certain species, and the morphological changes that take place dur-
ing the long prepupal period.

THE Case.—In length the case, figure 120, is about 13 mm.
It has the form of a cylinder, made of fine sand grains, tightly
cemented with tough, brittle silk. The cylinder is slightly curved
toward the ventral side. Along the sides of the case there are
several flat ballast stones.

In the prepupal or pupal state, the condition in which the cases
are almost always found, the ballast stones are larger than those
used during the active period, and each end of the cylinder is
capped with a large pebble, figure 119.

Larve of at least two undescribed species were collected.

NEOPHYLAX CONCINNUS.

Hasrtat.—tThe species, in the immature stages, is common in
the riffles of most upland streams of the region, such as Spherium
Stream, Michigan Stream, and many others. It does not seem
to occur in spring basins; nor is it common in the warm water
of the lowlands, though a few specimens have been found in Cas-
cadilla Creek and in Coy’s Glen.

LarvaL Hasits.—During the winter and early spring the
larve crawl over the stream’s bottom, feeding and storing up fat
to carry them over the long prepupal period, lasting through the
entire summer. As spring advances they seek the support of
some solid object, such as a submerged rock or log. Here the cases
are firmly attached, often great numbers of them on a single
rock, with the bodies parallel, like cords of wood.

In late spring, when the larve have attained full size and have
attached their cases to some solid object, the sieve nets are spun
across the ends of the cases, and the prepupal state begins.

In sealing the case the larva does not cover the ends with a
silken mesh, as do other species of the family, even when flat stones
also are used. Neophylax selects a stone for each end of the
case that is slightly larger than the diameter of the tube. These
stones are tightly cemented over the ends of the case with thick
sheets of cement-like silk. On the ventral surface of the cephalic

73

NORTH AMERICAN CADDIS-FLY LARVZ.

end the sand of the tube is cut away in semi-circular form and the
opening thus formed is covered with a lattice-like arrangement
of heavy rods of silk, figure 119. This end of the case is held
above its support by a short stalk of silk. At the caudal end of the
case a semi-circular opening is not made, but the lattice-like silk.
rods are made between the end rock and the ventral surface of the
tube. Usually the rods are overlapped by the edges of the case
and are invisible from the outside.

During the long prepupal period, lasting several months, from
late spring until the latter part of August, the larve remain quiet
with their heads folded between their legs. During this period
they are incapable of taking any food, and dissection shows the
alimentary canal entirely void of material of any kind.

If, during this period of helplessness, the stream recedes enough
to dry the cases, the larve perish, unable to reach the water, which
may be but a fraction of an inch below.

Preriop oF EmERGING.—Adults emerge about the end of the
first week of October, and continue on the wing until the middle
of November. They are weak flyers and do not wander far from
the stream’s edge.

Description oF Larva.—Length (in natural position, with
head turned under thorax), 8—1o mm.

Head.—In form, the head, figure 115, is long and tapering
from the eyes to the mouth parts, and quite abruptly rounded be-
hind the eyes. The frons, figure 116, seen in profile, has a de-
cided mound-like prominence at the point between the two eyes.
In color, the dorsal surface of the head bordering the frons is
dark-brown, almost black on the cephalic portion, but becoming
lighter as it progresses back; the frons is dark-brown, except an
irregular mark of light color, figure 116; behind the dark mark
bordering the frons the head is irregularly spotted with light-
brown; the sides of the head are light-brown, except a narrow
area surrounding each eye, which is almost white; on the under
side of the head there is a broad mark of brown, which gradually
shades into the light color of the sides, except along the cephalic
margins, where it is narrowly connected with the dark color of
the dorsal surface.

Thorax.—The prothorax above, figure 115, is light straw color,
74

LIMNOPHILID&.

with a dusky border along the cephalic margin and dark mottling
on the caudal half; on the under side there is a chitinous plate of
dark-brown color in front of the caudal margin of the segment.

NEOPHYLAX CONCINNUS.

115. Larva. Head and thorax. 119. Respiratory openings of pupal
116. Larva. Frons. case.
117. Larva. Labrum. 120. Pupal case.

118. Larva. Distribution of gills.

On the mesothorax the chitinous plates above the articulation
of the coxe extend up to the lateral margins of the dorsal shield,
with which they are narrowly united; on the under side of the
segment there is a pair of chitinous plates in front of the caudal
margin; the dorsal plates, figure 115, have a varying pattern of
dark-brown on a lighter field.

Abdomen.—On the first segment the dorsal hump is repre-
sented by an elongate chitinous plate; the lateral humps are prom-
inent and of darker color than the surrounding cuticle; on the
dorsal surface there is a line of sparse sete passing in front of
the dorsal hump and ending well above the middle of the lateral
humps; on the ventral surface there is an elevation which bears
a pair of small chitinous spots, each with a single seta; midway
between this elevation and each lateral hump there is a thumb-like
structure of doubtful function. On the ventral surface of seg-

75

NORTH AMERICAN CADDIS-FLY LARVZ.

ments three, four, and five, there is a transverse elliptical ring
of chitin. The gills, figure 118, are weak and of varying number.

DESCRIPTION OF THE CasE.—The case of the mature larva is
about ten millimeters in length. It is constructed of small or
minute sand grains, firmly cemented together in the form of a
slightly flattened and slightly curved tube. On each end of the
tube the larva cements one or more heavy “ballast” stones, figure
120.

NEOPHYLAX AUTOMNUS.

LarvAL Hasirs.—The larve are found in spring basins and
in spring streams near their sources. In the McLean region they
are especially abundant in Big Spring and its outlet for a few hun-
dred feet. They do not seem to occur in streams far from their
sources, nor have they been found where there is any great inflow
of surface water. These spring streams, in which the larvae
occur, are swift-flowing, with stony bottoms, and practically void
of vascular plants and of sticks and surface litter.

LarvaL Hasits.—In habits the larve do not seem to differ
from N. difficilis.

The prepupal behavior, also, is apparently like that of N.
difficilis.

Prertop oF EMERGING.—Adults are on the wing from late Sep-
tember until early November.

Description oF Larva.—Length (in natural position, with
head turned under thorax), 7 mm.

Head.—In form the head, figure 121, is similar to that of N.
difficilis, except that it is narrower across the cephalic margin. In
color it is deep mahogany-brown, almost black, except a light-
colored semi-circular area around the under surface of each eye,
and some small light-colored spots behind and beneath the eyes.
On the frons, figure 122, there is a thorn-like projection that is
plainly visible in profile view.

Thorax.—The cephalic third of the prothoracic shield, on the
dorsal surface, is creamy white; behind this light area it is dark
smoky-gray. The mesothoracic shield is smoky-gray with indis-
tinct markings, and bordered on the lateral and caudal margins
with black, as in figure 121.

76

yeas eee

SERICOSTOMATIDEA.

DESCRIPTION OF THE CasE.—The case differs from that on
N. concinnus only in its slightly smaller size, and in the smaller
number of the “ballast rocks” used during the prepual condition.
The manner of sealing the case before pupation does not seem to
differ from that of the previous species.

NEOPHYLAX AUTOMNUS.

121. Larva. Head and thorax. 123. Larva. Distribution of gills.
122. Larva. Frons.

FAMILY SERICOSTOMATID£E.

The family, as it now stands, consists of four widely-separated
subfamilies. No group characters have been found that will
satisfactorily include the larve of these subfamilies and exclude
members of other families.

The same evidence of distant relationship prevails in the habits
as in the classification. For this reason no attempt is here made
to discuss the family as a whole, but the known local species will
be described and discussed under their separate headings.

HELICOPSYCHE BOREALIS.

Hasirat.—The larve are found in almost all stony streams
of the region, and also occur on the rocks of exposed shores of
Cayuga Lake. Vorhies, who studied the Trichoptera of both
streams and lakes in Wisconsin, found the larve only in the lakes.

th

NORTH AMERICAN CADDIS-FLY LARVE.

In view of this discrepancy in habitat, and also in the difference
of size of both adults and larve, it seems probable that there are
more than one species in the genus. Dr. Betten, however, after
careful study of a large number of adults, could find no characters
for distinction, except size, and recognizes but one American
species in the genus.

Hasits.—In many of the streams about Ithaca the larve are
very abundant, but are difficult to discover during larval life, while
they live among the sand and gravel of the stream’s bottom.
Shortly before pupation they attach their cases firmly to some sub-
merged rock or log, usually selecting a rough surface. At this
time they often display a gregarious instinct, large numbers con-
gregating within a very small area. It is during the prepupal and
pupal periods that they are most often collected.

PrEriop oF EMERGING.—Adults emerge from the latter part of
June until the end of July.

Description oF LArvA.—Length, 6 mm. The larva, when re-
moved from case, assumes a spiral position of at least one and a
fourth turns.

HELICOPSYCHE BOREALIS.

124. Larva. Head and thorax. 127. Larva. Chitinous support,
125. Larva. Frons. middle leg.
126. Larva. Drag-hook. 128. Case.

78

——

SERICOSTOMATIDZ.

Head.—The dorsal surface of the head, figure 124, is dark-
brown, except along the margins of the frons, where there is a
very narrow light line which broadens at the constriction of the
sclerite; there is also a light-colored area in front of the caudal
margin of the head, and a light circular area surrounding each
eye. The caudal third of each side of the head has numerous light-
colored muscle-attachment marks. On the ventral surface the
head is white, with several conspicuous dark-brown muscle-attach-
ment marks on each side of the gula.

The Thorax.—The pronotum, figure 124, is brown, with a
varying pattern of light and dark marking; on each side of the
segment the chitinous support for the leg has a deep notch, figure
127, into which a tongue-like extension of the coxa hinges.

Abdomen.—On the first segment the dorsal hump is absent, and
the lateral humps are but slightly raised and are thickly covered
with minute spines, arranged in pairs. Gills and the lateral fringe
are absent. The drag-hooks bear several long teeth, figure 126,
giving each hook a fan-like shape.

The abdomen is curved to fit the form of the case, as the insect
lives with its ventral side toward the axis of the whorl.

DESCRIPTION OF THE CasE.—The well-known spiral case, fig-
ure 128, quite closely resembles some of the fresh water molluscs,
for which it has been more than once mistaken and described. It
is made of minute sand grains, securely cemented together. The
tube in which the larva lives is broadest at the mouth and tapers
gradually to the tip.

Though the molluse-like case of the genus Helicopsyche is a
unique plan of architecture, it is not such a wide deviation from
the cases of other Trichoptera as appears on first sight. Ap-
parently the larva starts its case in somewhat the form of a minute
horseshoe and, continuing the cephalic end around the caudal end,
builds on until the spiral form is reached, ever-increasing the di-
ameter as it builds around the circumference.

Such a case would be made by a species that makes a cornu-
copia-shaped dwelling, such as Leptocerus ancylus, figure 167, if
the bend in its case were very greatly increased and the tube
slightly elongated.

Before pupation the case is tightly glued to some solid sup-
port and the cephalic end is closed by a convex lid of silk, with a

79

NORTH AMERICAN CADDIS-FLY LARVZ.

split-like respiratory opening on the side toward the axis of the
whorl. Behind the caudal end of the pupa a flat sheet of silk with
several respiratory openings crosses the interior of the case.

GOERA CALCARATA.

Hapirat.—The larve are found in riffles of the large streams
of the region, both in the uplands and near the lake’s level. They
also occur on stones in wave-beaten areas on Cayuga Lake’s shore.

Hasits.—Little has been learned of the habits of the larve,
beyond the fact that they are found crawling over the surfaces of
bare, current-swept rocks from late summer until the end of
March, when they attach their cases firmly on the exposed edges
of stones, together with Psilotreta and a few other species of the
rapid waters.

Preriop oF Emercinc.—Adults emerge during the last week
of April and the first week of May.

Description oF Larva.—Length, 1o—12 mm. There is a
heavy chitinous spur above each mesothoracic leg, grooved on its
cephalic margin to fit a groove on the lateral margin of the prono-
tum.

Head.—The back part of the head, figure 129, on the dorsal
surface, is flattened and slopes toward the caudal margin; in front
of this flattened area, whose boundary passes in front of the eyes,
the head is cone-shaped, sloping toward the mouth-parts. In color
the entire head is uniform black-brown, except a slightly lighter
circular patch surrounding each eye.

The Thorax.—The pronotum, figure 129, is very heavily chit-
inized. The cephalic margin is inset so that the lateral margins
extend forward in sharp points. The lateral edges are thick and
deeply grooved, apparently to fit the grooves of the heavy chitinous
spurs of the mesothorax.

On the mesonotum there are two pairs of large chitinous plates,
figure 129, Above each mesothoracic leg there is a very heavy
chitinous spur, grooved on its cephalic margin, which projects
well beyond the cephalic margin of the segment.

The metathorax bears four pairs of chitinous plates, figure 129.

It is to be observed that in the European fauna the genus
Geera has two pairs of plates on the mesonotum and only three
pairs on the metanotum, while the genus Silo has four pairs of

80

i a tal

: SERICOSTOMATID&.

plates on the metanotum, but has three pairs on the mesonotum.
Thus G. calcarata seems to fall in neither of these genera. The
adult, however, seems to agree best with the genus Gera.

xe
XD

rasa
Os
aes

= EES mez

GOERA CALCARATA.

129. Larva. Head and thorax. 131. Larva. Frons.
130. Larva. Labrum. 132. Case.

The Abdomen.—On the first segment the dorsal hump is well
developed ; the lateral humps are present, but flattened. Branched
gills and the lateral fringe are present. The drag-hooks are stout
and bear but a single spur.

DESCRIPTION OF THE CaseE.—The case, figure 132, has the
form of a tube of fine sand grains. The tube is very slightly bent
and is slightly flattened on the ventral side. Fastened to each side
of the tube are heavy ballast stones—usually two to each side.

Before pupation the larva places a stone over the opening at
each end of the tube. Across the face of each stone a solid sheet
of silk is spun. In the crevices between the stone and the tube
a series of elongate respiratory openings are left. The case is
fastened to its support by a stalk of silk at each end.

The preparation for pupation, like the form of the case, is
very similar to those of Neophylax.

6 81

NORTH AMERICAN CADDIS-FLY LARVE.

BRACHYCENTRUS NIGRISOMA.

Hasirs.—During the first six weeks of their lives the larve
are active, crawling about in quiet eddies along the banks of
the stream in search of food. After this period they move to
the center of the stream and live sedentary lives, with one edge
of the large end of their cases firmly cemented to submerged rocks
or sticks. Always they inhabit positions on the exposed surface
of their support and always they face the unbroken current. While
waiting for prey they assume the position shown in figures 142
and 144, protruding their heads slightly and extending their pro-
thoracic legs straight forward. ‘The mesothoracic legs are held
upward while the metathoracic legs are extended to the sides.
From this position they eagerly seize and quickly devour small
larve or bits of vegetation that float within their grasp.

In the unnatural conditions of still-water aquaria in the lab-
oratory they attach their cases and assume their characteristic
attitude of outstretched arms. If a particle of food material be
moved within their grasp it is eagerly seized and devoured, but if,
however, the food be placed in front of the larva, even in contact
with its limbs or jaws, it is ignored or pushed aside. Apparently
the larva does not recognize food that is not moved into its grasp.
From time to time larve confined in aquaria detached their cases
and moved from place to place. It seems probable that the larve
in the streams, also, at times move about in search of building
material, for it is unlikely that chance would place enough suitable
case-building material within their reach.

Larve which were put in the water after they had been ex-
posed to the air until the moisture had dried from their cases,
which accordingly floated, swam with their legs motionless and
in the attitude assumed while waiting for prey. Their motion
through the water was caused by the respiratory current being
forced through the small openings at the caudal ends of their
cases, somewhat after the manner of locomotion of certain dragon-
fly nymphs. This was probably an unnatural mode of locomotion,
never practiced in nature, at least not by this species.

In preparation for pupation the larva spins a silken sheet,
figure 148 C, across the front of the case. This sheet is perforated
in the center by a number of small holes arranged in a circle. Sur-
rounding the perforations there is an area which is free from

82

eC

SERICOSTOMATIDE.

perforations. At the caudal end of the pupa (about two-thirds
the length of the case from its cephalic end) a second sheet of
silk, figure 148 B, crosses the case. This second sheet resembles
the first, except that the circular area of perforations is larger.
Pupation takes place on the exposed areas on sticks or stones
where the larval life was spent.

PERtop oF EMERGING.—Specimens confined in cages in their
natural habitat emerged during the latter part of May and first
part of June.

Foop oF THE LARvai.—According to Miss Helen Murphy,
who followed the species from the egg to the adult, “the cases
are completed in about five hours. The larve then start to eat.
For the first two weeks the food consists entirely of diatoms,
such as Meridion, Cymbella, Navicula, Cocconema, Fragilaria, and
Synedra. This food they obtain by browsing on the stones and
vegetation, over which they hastily scramble. At the end of the
third week the green alge Oedogonium, Cladophora, Ulothrix,
Cylindrospermum, and bits of seed plants are added to the diet.”

“At the end of the sixth week the larva is about three-six-
teenths of an inch in length.” ‘From a purely herbivorous diet,
obtained by active searching, they now become mainly carnivorous,
waiting in a most receptive attitude for whatever may come
within their powerful grasp.” “An examination of their stom-
achs at this time reveals quantities of fragments of mayflies, Hy-
drachnids, Chironomids, and Crustacea, as well as Chlorophycez
and diatoms of several genera. ‘This miscellaneous assortment of
animal and vegetable foods from the stomachs, as well as observa-
tions on the habits of the larve, leads us to believe that they will
eat any organic matter that floats within their grasp. The combs
of fine spines on the legs (figures 134, 140, and 146) seem to serve
as plancton sieves, and the long, hooked armature of the tarsus
certainly is adapted to a carnivorous diet.”

DESCRIPTION OF THE Larva.—The length of the mature larva,
figure 133, is about 12 mm.; its breadth is about 2.5 mm. In life
the soft parts are green; the heavily chitinized parts are dark-
brown, appearing black when viewed in reflected light. The ab-
domen tapers gradually from the first to the last segment.

The Head—rThe head is black, marked with brown on the

83

Aue

nll

il

! it li

ase AAR Ababa

(See Page 85 for Description of Cut.)

84

dorsum, figure 133; the sides are black, with a brown mark ex-
tending back from the caudal margin of the eye to the caudal
margin of the head as shown in the figure; the venter is black,
except the ventral mouth-parts, which are brown; the labrum is
black, with sete arranged as in figure 139; its cephalic pair of
sete are saber-like and are directed toward the median line, their
tips almost meeting; the other sete: are normal; the front margin
is clothed with a dense fringe of hairs; the frons has the markings
and distribution of setz, shown in figure 147.

The Thorax—tThe thorax is marked on the dorsum, as in
figure 133; the prothorax has a depressed crescentic mark of
brown across the dorsum and extending down the sides ; the meso-
thorax is armed dorsally with four narrowly separated chitinous
plates, which are without markings, but are armed with long sete,
figure 133 ; on each side of the body there is a somewhat triangular
plate; the metathorax is armed above with four smaller dorsal
plates and a single plate on each side of the body, figure 133; on
the sides the chitin of the dorsum of the prothorax extends to the
base of the front legs; on the outside of each mesothoracic coxa
there is a triangular piece of heavy chitin which bears a tuft of
long, black sete on its front and on its ventral corners; the meta-
thorax bears similar chitinous pieces, each of which has a single
line of long, black setee around its cephalic corner and a line of
similar sete, extending from a point on its cephalic margin well
above its ventral corner to a point on its venter considerably below
the limits of the chitinous triangle; the venter of the thoracic seg-
ments is without heavy chitin. The legs, figures 134 and 146, are

BRACHYCENTRUS NIGRISOMA.

133. Larva. Head and thorax. 141. Larva. Mandible.

134. Larva. Front leg. 142. Larva in case. Natural posi-

135. Pupa. Chitinous plates of left tion, cephalic view.
side of abdomen. 143. Adult. Male genitalia, caudal

136. Larva. Distribution of giills. view.

137. Pupa. Detail of group of 144. Larva in case. Dorsal view.
hooks, 2nd __ series, 145. Larva. Lower mouthparts.

segment 5. 146. Larva. Middle leg.
138. Larva. Drag-hook. 147. Larva. Frons.
139. Larva. Labrum. 148. Pupal case. a) caudal end of
140. Larva. Part of comb of 2nd case. b) caudal sieve.
leg. c) cephalic sieve.

85

\

NORTH AMERICAN CADDIS-FLY LARVZ.

all armed with powerful curved claws; the form and distribution
of sete is shown in the accompanying figures; the apical mem-
branous part of the front femur adjoining the tibia is somewhat
soft and is overspread with minute conic teeth; the inner edge of
the trochanter and femur of the front leg is armed with a single
row of long straw-colored hairs, and the femur is armed also with
a row of short spines on its inner edge; the second and third pairs
of legs are much alike; the inner edge of the femur is armed with
a line of sharply-pointed spines of two kinds—one kind, apparently
very rigid, is dark in color and arises from well-defined sockets ;
these spines are separated by one, two, or three spines of lighter
color and apparently less rigidity, which do not arise from sockets ;
the spines in detail are shown in figure 140.

Figure 136 illustrates diagrammatically the arrangement of
gills on the left side of the abdomen.

DescRIPTION OF THE Pupa—Length, 1o—13 mm.; breadth,
3—3.5 mm.

The mandibles are strongly chitinized. The antenne reach to
the tip of the abdomen. The dorsal plates of the abdomen and
armature of the dorsal surface of the first segment are shown in
figure 135; the hooks of the second series on the fifth segment are
not borne on a single plate, but occur as independent chitinous
pieces, forming a line across the dorsum of the segment. Figure
137 shows the hooks in detail. A few minute sete occur on each
segment—these are slightly longer and more numerous on the last
segment ; the lower sides of segments I to 7 bear narrow obliquely
downward-pointing lines of dark color; the last segment is shaped
like an obtuse arrowhead. When viewed from above its two curved
processes are equal to a little more than half its length. The
lateral fringe is better developed than that of the larva; it begins
behind the middle of the fifth segment and ends on the ventral
side of segment eight.

THE CasE, figure 144, is 15—18 mm. wide at its anterior end
and about 1.5 mm. wide at its posterior end; it is constructed of
minute twigs, root fibers, and fragments of wood cut to the proper
length to give even and straight edges, gradually diverging toward
the anterior end. In cross-section the outer surface of the case
is square ; the interior is lined with a cylindrical tube of tough silk,
which is equal in diameter to the inside diameter of the square

86

CALAMOCERATIDE.

exterior framework ; the spaces between the corners of the square
exterior and the silken tube are filled with silk. At the caudal
end of the case, figure 148 A, the tube narrows abruptly, leaving a
circular opening about one-half mm. in diameter. So toughly
made are these cases that they persist without deterioration from
season to season after their occupants have left them.

FAMILY CALAMOCERATIDé.

This small family is represented in North America by but
eight described species. Other members of the family, except
two species in Europe, occur in remote countries where little or
nothing has been done with the immature stages.

For this reason it is impossible to assemble a group of family
characters with any degree of certainty that they will include all
of the species of the family when these become known.

Ganonema americanum, the only known American larva, is
described below.

GANONEMA AMERICANUM.

Hasirat.—The larve are abundant in the alder-bordered
streams of Michigan Hollow and McLean Swamp.

Hasits.—The larve are active during the summer, fall, and
winter. In February, with the thermometer below 20° Fahr.,
they were apparently as active as during the heat of summer. By
the end of April they had left the middle of the stream and had
firmly attached the anterior ends of their cases to solid supports
near the stream’s margin. At this time flat stones were fastened
over both ends of their cases—a frequent practice of the larve at
all seasons during periods of rest.

The wood-boring habits of this species may, when we are
familiar with more species, prove a not uncommon method of
case-making. I have found identical cases in streams on the West-
ern slope of the central range of the Colombian Andes, and also
in the Valley of the Magdalena River, east of this range. Similar
habits are described and figured by G. V. Hudson, in ‘““New Zea-
land Neuroptera,” 1904, for Triplectides obsoleta (Pseudonema
obsoleta) of the family Leptoceride. Hudson, however, states
that T. obsoleta under natural conditions sometimes constructs
cases of fragments of leaves.

87

“hy
7a

(See Page 89 for Description of Cut.)
88

CALAMOCERATID&.

Food.—The food of the larve, as demonstrated by examina-
tions of the contents of many stomachs at different seasons, con-
sists of fine powder rasped from submerged wood.

PERIOD OF _E.MERGING.—The specimens in captivity emerged
from June 4 to July 11.

DEscRIPTION OF THE Larva.—Length, 18—2o0 mm.; width,
3 mm. Color of chitinous portions of head and thorax, black
when viewed with reflected light; when viewed with transmitted
light, mounted specimens show faintly lighter markings. The
legs are black, ringed with white. Fleshy portions of prothorax
and abdomen are pale-brownish white. The anal hooks are brown.

The Head.—The head is narrowest at its anterior end and
broadens very gradually to near its base, where it narrows. Behind
the place of its greatest diameter it is inclosed within the first tho-
racic segment. The distribution of sete on the dorsal surface is
shown in figure 149. The frons, figure 160, has a semi-circular
line of sete, curving away from the cephalic margin and three other
more widely-separated sete near each side. Like the heavily chiti- _
nized portions of the head and thorax, the frons is thickly marked
by minute transverse lines, from each of which arise several very
minute hairs, giving, except under high power, a somewhat scale-
like appearance. The mandibles, figure 154, are deeply grooved
along their inner margin to the very tip of the apical tooth. Be-
sides the apical tooth, two lateral teeth are present on each edge
of the groove. From the groove arise three well-defined brushes
of hair. The inner brush is directed inward and backward; the
middle and cephalic brushes are directed inward and toward the
front; the cephalic brush is the most dense and is composed of
extremely fine hairs. The labrum, figure 152, is crossed by a row

GANONEMA AMERICANUS.

149. Larva. Head and thorax. 156. Larva. Front leg.
150. Pupa. Mandible. 157. Pupa. Anal appendages, dor-
151. Case, longitudinal section. sal view.
152. Larva. Labrum. 158. Larva. Detail of hooklets cov-
153. Larva. Hind leg. * ering lateral humps.
154. Larva. Mandible. 159. Larva. Distribution of gills.
155. Larva. Terminal abdominal 160. Larva. Frons.
segments. Lateral 161. Pupa. Chitinous plates of left
view. side of abdomen.

NORTH AMERICAN CADDIS-FLY LARV.

of 18 to 20 strong sete whose bases almost touch, except on the
median line, where there is a greater space. On each latero-
anterior angle there is a patch of long, fine hairs, and in the middle
of the cephalic margin a dense line of short hairs.

The Thorax.—Prothorax heavily chitinized above and on the
sides. The area between and in back of the coxal cavities is mem-
branous, except two narrow spots immediately in front of the
mesothorax. Mesothorax with a chitinous area which extends
back over the metathorax as far as the caudal margin of the hind
coxe. Within this area there is a well-defined, square bearing
eight sete, figure 149. The sides are not chitinous, except for a
small black triangle behind each coxa, which bears a circle of
about twelve sete; the venter is free from heavy chitin, except
for two narrow yellow spots on the caudal margin. The meta-
thorax is without heavy chitin above. On the sides the distribu-
tion of chitinous plates is the same as on the mesothorax; the
upper mark, however, is not so dark in color as on the preceding
segment and bears more sete, which are less nearly circular in
arrangement. The venter differs from that of the mesothorax,
only in having the chitinous areas near the caudal margins darker
in color. The front leg, figure 156, is little more than half the
length of the succeeding legs, but is more robust. It bears three
stout spurs on the inner angle, next to the tarsus, and one isolated
spur on the distal margin. On the inner margin of the basal
segment of the tarsus there is a single row of short stout spines.
The inner surface of the tibia bears numerous very short spines.
The inner surface of the femur is sparsely armed with short tri-
angular teeth. The coxa, on its inner margin, has a few short
spines and over its entire surface has rows of fine, short hairs
like those described for the frons. The two succeeding legs (fig-
ure 153 shows the hind leg), differ from the front leg in being
longer and less robust, and in having fewer and weaker short
spines. Each of these legs has but one tibial spur.

The abdomen is cylindrical and almost uniform in circumfer-
ence throughout its length. The humps on the first segment are
not greatly developed. ‘The lateral humps bear an area of short,
curved spines, whose points are directed forward. The gills are
distributed on segments 2 to 8, above and below the lateral line, as
diagrammed in figure 159. The lateral fringe, near the caudal

go

CALAMOCERATIDE.

margin of the seventh abdominal segment, ends at the beginning
of a fleshy raised line, figure 155, which crosses the suture between
the seventh and eighth segments and, inclining upward, extends
to the caudal margin of the eighth segment. Each side of this
fleshy line is armed with curved, bifurcate spines directed back-
ward. The anal hooks and the arrangement of sete on the last
abdominal segments are shown in figure 155.

DESCRIPTION OF THE Pupa.—Length, 13 mm.; mandible, fig-
ure 150. ‘Tarsi flattened and fringed on each side by a row of
black swimming hairs. Lateral fringe black. A narrow black
line parallels the lateral fringe beneath, extending to the caudal
margin of the eighth segment, where the two converge. A nar-
row black line above the lateral line contains the spiracles. Ab-
dominal segments 2 to 9 have tufts of hair near their caudal
margins above. On the caudal margin of the first abdominal seg-
ment there is a pair of lobes, figure 161, covered with sharp spines.
Above these lobes are sparse backward-pointing teeth. The chiti-
nous plates of the abdomen are shown in figure 161. The pos-
terior end of the pupa is represented in figure 157.

Tuer Case.—The cases made by this species differ greatly from
those of other described American Trichopterous larve. Instead
of the usual dwellings of stones or twigs, or tubes of silk, these
utilize fallen twigs of wood from the stream-bottom. The twigs
are hollowed from end to end, and lined with silk, forming porta-
ble cases, which are a natural part of their surroundings. These
larve abound among the litter of branches and twigs from the
surrounding forest. In spite of their abundance they are most
inconspicuous among the débris. They crawl with a jerky motion,
as if swayed by the passing current, or rest, as if lodged, on a sub-
merged branch, and when disturbed, let go, drifting down stream
with the current.

The twigs used in cases vary greatly in length and diameter,
apparently being selected at random from the litter on the bot-
tom of the forest stream. Sometimes pieces of heavy bark or
fragments of broken wood are used. A cylindrical hole always
penetrates the wood from end to end. In some twigs the chamber
forks near the anterior end, one outlet curving downward and
opening to the exterior at one side, while the other perforates the
end of the stick. The side outlet, when present, forms the anterior

gi

NORTH AMERICAN CADDIS-FLY LARVE.

entrance to the case, the other in the end being plugged with silt
or with small pebbles. Sometimes the chamber curves downward
without forking, as in figure 151. The chamber is always lined
with silk. (Figure 151 represents a case with the silk tube cut
away, except around the larva.) Although there is considerable
variation in the size of the twigs used, their average size increases
with the growth of the larve. To ascertain how the change in
cases is made, several experiments were made with captive larve.
Some were removed from their cases and put in cages with twigs
of appropriate size. These larve did not attempt to use the wood
for making new cases, but merely spun silken tubes to which
particles of silt adhered ; others, which had one side removed from
their cases, repaired the damage with silk and silt. One larva
repaired the damaged side with silk and fragments of bark and
then proceeded to cut away the two ends of its case. It worked
from the damaged side of the case, cutting narrow incisions across
the twig until the opposite side was reached. The operation of
cutting the two incisions across the twig ten millimeters in diam-
eter consumed about twenty-four hours. ‘Two specimens, which
were retained in aquaria in the laboratory, attached the anterior
ends of their cases securely, by means of silk, to the ends of solid
twigs, and then drilled into the wood, emitting, during the task,
an abundance of very finely-powdered wood. One of these new
dwellings proved too long for its occupant. It was accordingly
girdled with a circular incision, which was deepened until one end
of the twig was completely cut away. Several sticks similarly
ringed were found in the creek where the larvee occur. No doubt
this is the usual method of changing cases, as larval growth pro-
ceeds.

FAMILY ODONTOCERID.

This small family is represented in the American fauna by
but a single species with known immature stage.

DistiNcrivE CHaracters.—The labrum is distinctly longer
than broad. The pronotum and mesonotum are chitinized; the
metanotum has four chitinous plates, the two median of which
are much broader than long, crossing the median line.

The Head.—The head is depressed in form. The labrum is
longer than broad, with two pairs of cycle-shaped, pale sete on

g2

ODONTOCERIDZ.

the front margin. The pleure are contiguous behind the small,
triangular gula.

The Thorax.—The pronotum is extended in a thorn-like point
at each cephalic corner.

The mesonotum is completely chitinized.

The metathorax bears two broad chitinous plates transversely
across the dorsal surface, and a single plate on each side.

PSILOTRETA FRONTALIS.

Hasirat.—Psilotreta larve inhabit almost all of the larger
streams of the uplands, but are never found near Cayuga Lake’s
level. They are especially abundant in Mud Creek, near Free-
ville.

In the upland streams the larve are confined to the riffles,
and the portions of the streams with stony bottoms.

Hasits.—During their early life the larve are free moving,
crawling over the stream’s bottom. At this time they show no
evidence of social instinct, coming together only by chance in
their wanderings.

In the early spring, just before pupation, the larve develop
a remarkable gregarious habit. Almost all of the larve within
certain areas of the stream congregate on the sides of a few se-
lected stones in such numbers that their cases are sometimes piled
one on top of another to a depth of an inch or more, while other
stones of the region are entirely uninhabited. The cases are al-
ways placed parallel to each other, with their cephalic ends directed
toward the surface of the water. Such congregations of cases
may often be removed entire from the supporting stone, when the
mass has much the form of a cord of neatly cut wood.

Periop oF Emercinc.—Adults emerge during the latter week
of May and the first week of June.

DEscripTION oF LarvA.—Color in life deep blue-green.

Head —On the dorsal surface the head is flattened. In color
it is deep mahogany-brown, with a light line commencing at each
eye and extending back to the caudal margin, and a narrow light
cephalic border to the labrum, figure 162. On the ventral surface
the head has a light-brown median mark, which shades into deep
mahogany-brown toward the lateral margins.

93

NORTH AMERICAN CADDIS-FLY LARVZ.

The Thorax—The chitinous shield of the pronotum is ex-
tended forward in thorn-like form at each cephalic corner. In
color the pronotum is deep mahogany-brown, with a broad, lighter-
brown line on each side of the median suture.

PSILOTRETA FRONTALIS.

162. Larva. Head and thorax. 164. Larva. Frons.
163. Larva. Labrum. 165. Case.

The shield of the mesonotum is deep mahogany-brown, with
a lighter line on each side of the median suture, which, in some
specimens, ends at about the middle of the sclerite, and in other
specimens extends back to the caudal margin of the shield.

The metanotum, figure 162, bears a broad, brown, transverse
plate near the cephalic margin, behind which there is a pale, nar-
row, transverse plate; on each side of the erate there is an
elongate brown plate.

The Abdomen.—On the first segment all three spacing-humps
are represented by obtuse mounds. The gills of the subdorsal
and subventral series are well developed, occurring in tufts of
from five to twenty-five filaments behind the cephalic margin of
the segment. The lateral series of gills is represented by a few
weak filaments on the first three or four gill-bearing segments,
or is entirely wanting. The drag-hooks are stout, with heavily
chitinized supports on the prolegs.

94

LEPTOCERIDE.

DESCRIPTION OF THE CasE.—The case of the mature larva,
figure 165, has the form of a slightly-curved cylinder of sand
grains. Immature larve cases differ only in being tapered
toward the caudal end.

The case of the pupa has a flat pebble set neatly within the
aperture at each end of the tube. All spaces around these stones
are tightly closed with heavy silk, leaving no respiratory aper-
tures. The habit of enclosing the pupa tightly, without provision
for respiratory currents, is unusual among case-building Trichop-
terous larve, but is always practiced by the cocoon-making family,
Rhyacophilide.

FAMILY LEPTOCERIDé:.

Hapitat.—The known Leptocerid larve of the American
fauna are inhabitants of standing waters—lakes, ponds, and the
dilatations of streams—except Leptocerus ancylus, which is found
on stones in the riffles of streams, as well as on the stones of wave-
beaten lake shores.

Though the most abundant of our Trichoptera belong to this
family, the early stages of but few have been described, and the
habits of these few are but imperfectly known. At times, during
the early days of July, the black iron bridge across the northern
end of Cayuga Lake appears as white as snow, with millions of
adult insects of this family, mostly the beautiful snowy species of
the genus Leptocella. At such times a passing train sends a cloud
of countless numbers of the insects into the air, after a few min-
utes’ flight to settle again as a white covering upon the bridge.

Hasits.—The habits of so few species of our fauna are known
that it does not seem advisable to generalize on the activities of
the entire family. Those that are known will be described under
the various species.

DEscRIPTION OF THE Larvai.—Distinctive characters. A
suture beginning in the region of the eye dips downward and ex-
tends back to the hind margin of the head. The femur of the hind
legs, and in most species of the middle legs, is divided into two
segments.

The Head.—The head is oval, with long antennz arising close
behind the mandibles. The labrum is much broader than long,

95

NORTH AMERICAN CADDIS-FLY LARVZ.

and never possesses a row of twenty or more heavy bristles. The
gula is subquadrate, widely separating the epicrania.

The Thorax.—The pronotum is chitinous. On each side of
the prothorax a chitinous plate, differing somewhat in form in
different species, extends forward above the base of each coxa.

The mesonotum is chitinized.

The metanotum lacks chitinous plates.

The legs will offer unusual taxonomic opportunities when they
are more thoroughly studied and the homology of the segments
is better known.

The forelegs are short, broad, and flat, with varying armature
in different species.

The middle and hind legs are slender and show great difference
in armature, and in the relative length of the segments. In the
hind legs of all known species, and in the middle legs of all except
Setodes, there is a short segment at the base of the femur, which
has led Ulmer to state that the femur is divided. It is not clear,
however, that this segment does not belong to the trochanter in-
stead of to the femur. Besides this suture, cutting off a sclerite
of doubtful homology, there is, as is usual in Trichopterous larve,
a suture near the base of the trochanter. In the Leptoceride this
suture separates a short basal piece from a much longer distal
piece.

The Abdomen.—On the first segment all three spacing-humps
are well developed. The lateral fringe is short and fine and ex-
tends from the third to the seventh segment. The basal segments
of the prolegs are fused to form an apparent tenth segment. The
claws are small.

In this family it is impossible to identify the species by frag-
ments of the cast larval skin retained in the case after pupation.
The exuvia is eliminated through the caudal opening of the pupal
case as soon as transformation from the larva takes place.

LEPTOCERUS ANCYLUS.

The larvee are common in all streams of the region, except
those of the highest altitudes; and they also occur on stones of
the wave-beaten shores of Cayuga Lake.

Vorhies, who first described the larve and adults, determined

96

_ LEPTOCERID.

the Ithaca specimens as identical with his material from Wiscon-
sin, in spite of the decided difference in form of the larve’s cases.
The color and soft parts of our specimens deteriorated in the
preservative fluid, but the structure of the chitinous parts is well
preserved. The fore leg of the larva is shown in figure 166.

LEPTOCERUS ANCYLUS.
166. Larva. Front leg. 167. Case.

In the Ithaca region the larve make cases of sand grains in
the form of curved cornucopias, figure 167, without lateral flanges,
and without decided hood-like covers on the cephalic ends. In
cross-section the cases are cylindrical.

The cases of the material from Wisconsin have decided lateral
flanges, and have well-developed hoods that completely cover the
larve’s heads.

NORTH AMERICAN CADDIS-FLY LARVE.

MYSTACIDES SEPULCHRALIS.

Hasirat.—The larve are common insects in Beebe Lake,
Dwyer’s Pond, and in many of the slow, deep pools of Cascadilla
and Fall Creeks.

Hasits.—The species lives among the accumulation of sticks
and rubbish on the pool’s bottom.

The prepupal state has its beginning from the middle of May
till the first part of June. At this time the cases are attached to
the exposed surfaces of submerged sticks. 4

Foop.—Stomachs of preserved specimens contained a thor-
oughly masticated pulp, apparently of vegetable origin.

Prriop oF EMERGING.—Specimens in captivity emerged from
the middle of June until the first part of July. Probably under
natural conditions their period of emerging is of considerably
longer duration.

DistincTivE CHARACTERS oF LArvA.—Length, 9 mm. With-
out swimming hairs on second and third pairs of legs.

Head.—The extent of the dark coloring varies greatly in
different individuals. In dark specimens, figure 168, the cephalic
part of the frons is smoky-brown; behind the brown area the
head is pale yellow, except for several sharply-defined spots behind
the frons; a dark mark begins behind each antenna and extends
back to the hind margin of the head; the sides of the head are
pale yellow with numerous dark-brown spots ; on the under surface
the head is dark-brown without markings.

Pale specimens have a ground color of light straw yellow,
marked by numerous brown spots. No other markings are present.

The Thorax.—The prothorax, like the head, is subject to great
variation in coloration. Dark specimens, figure 168, have the
ground color of the prothorax almost entirely dark-brown, almost
obliterating the mottling ; in such specimens a narrow, light-colored
line encircles each “shoulder.” In light-colored specimens the
ground color is pale, thickly mottled with dark-brown spots. All
intermediate gradations of coloration occur.

The mesothorax of dark specimens is smoky, mottled with
dark-brown, figure 168. In light specimens the smoky ground
color is lacking.

98

LEPTOCERID&.

The metathorax has a small chitinous plate bearing a few sete
on each “shoulder.”

The fore leg is broad and flat. The middle leg bears a tarsal
claw that is as long as the basal tarsal joint. The distal segment

MYSTACIDES SEPULCHRALIS.

168. Larva. Head and thorax. 170. Case.

169. Larva. Frons.
of the trochanter is more than twice as long as the basal segment.
The femur is divided into a long apical and very short basal piece.
The hind leg bears a tarsal claw about half as long as the basal
joint. The tibia has a swelling at about the middle of the segment
that gives the segment the appearance of being divided, though
carefully-prepared mounts have revealed no suture. The femur
is divided into a short basal and long apical piece. The basal piece
of the trochanter is short and the apical piece very long.

The Abdomen.-—The first abdominal segment has a prominent
bulb-shaped dorsal spacing-hump; the lateral humps are smaller ;
on the caudal side of each lateral hump there is a brown chitinous
plate with a black dorsal margin. Abdominal gills are absent. The
lateral fringe consists of weak, pale hairs. The drag-hooks are
stout ; chitinous supports at their bases are almost entirely wanting.

DEsScRIPTION oF CasE.—The case of the larva, figure 170, con-
sists of a slightly-tapering tube of sand grains, or minute bark

$9

NORTH AMERICAN CADDIS-FLY LARVE.

fragments, lined with silk. In length the tube is about 12 mm.,
and in breadth about 1.5 mm. On opposite sides are fastened
pine needles, or grass stems, or slender sticks, paralleling the tube
and extending well beyond its caudal and cephalic ends.

Before pupation a sheet of silk with a slender, minute, round
perforation in the center is spun across each end.

TRLENODES SP.

Hasirat.—The larve are common in the Cove, Michigan
Pond, and many ponds and dilatations of creeks that contain
Potamogetons and other aquatic plants.

Hasits.—The larve dwell ameng the branches of submerged
plants, seldom descending to the pond’s bottom. Unlike other
species that dwell in similar places, but must crawl from plant to
plant, the larve of Triznodes swim rapidly from place to place
through the open water.

Before pupation the cases are attached to the stems of plants
or rolled in submerged leaves.

Periop oF EmERGING.—Adults emerge about the middle of
June.

DisTincTIVE CHARACTERS OF Larva.—Length, Io mm. Long
swimming hairs on third pair of legs.

Head.—The ground color is straw yellow, figure 171; a dark
mark on each side of the frons begins at the outer corner of the
labrum and extends back to the hind margin of the head, with a
narrow break behind the antenna; on the ventral surface a smoky
area begins at the base of each mandible and extends back to the
hind margin of the head. The gula is pale. The frons, figure
172, is without pattern. The mandibles are brown.

Thorax.—The prothorax is smoky on the dorsal surface, shad-
ing to straw yellow on the sides. The chitinous supports at the
base of the legs are dark-brown and black. A thorn-like process
projects forward above the base of each coxa.

On the mesothorax the scutellum is of a pale, smoky color,
with indistinct dark spots. The pleural suture is long and narrow,
and deep black in color.

The metathorax bears no dorsal chitinous plates. The pleural

100

LEPTOCERIDE.

suture is very long, extending diagonally up and back three-fourths
the distance to the caudal margin of the segment.

The front leg is short and stout. The tibia is broadened on
its inner distal angle and bears a single spur. Projecting forward,
above the base of the leg, there is a flat chitinous projection which
differs but slightly from that of Setodes, figure 178.

TRIAENODES SP.

171. Larva. Head and thorax. 174. Larva. Middle leg.
172. Larva. Frons. 175. Case.
173. Egg mass.

The middle leg is longer and less stout. The femur is divided
into a long apical and very short basal piece. The trochanter has
the apical piece more than twice as long as the basal piece.

The hind leg is long and slender, and is provided with numer-
ous long swimming hairs. The distal piece of the trochanter is
much longer than the basal piece, appearing as a distinct joint.

The Abdomen.—On the first segment the spacing humps are
large and bulb-like; the lateral humps have no chitinous plates,
but have a thick fringe of microscopic forward-pointing hairs.
The lateral fringe is present, but is very weak. Large gills arising
singly occur on segments 2 to 8, inclusive. Except for the drag-
. hooks the prolegs are not chitinized.

IOI

NORTH AMERICAN CADDIS-FLY LARVE.

DescrrpTioN oF Eccs.—During the latter half of June egg
masses may be found on the under surface of floating leaves and
sticks. The gelatinous mass is disc-shaped, measuring about 5
mm. in diameter. Inside the gelatin the eggs are arranged in a
spiral of about 200 eggs, figure 173.

The egg masses occur in very great numbers, often completely
covering the under sides of submerged leaves, or even placed one
on top of another.

DescrIpTION oF CasE.—In form the case is an elongate cornu-
copia, usually measuring 1.5 cm.—2.5 cm. It is made of thread-
like sections of the epidermis of leaves, or the fine ribs of leaves,
wound in a spiral. The leaf sections are cut and fitted end to end
and side to side with wonderful skill and precision.

By the time newly-hatched larve have left the gelatinous egg
mass, they have constructed irregular, web-like cases of transparent
silk. To this silk case silt adheres. After two or three days from
the time of hatching the silk case is replaced by the characteristic
spiral case of the species.

SETODES GRANDIS.

Hasirat.—lIn the beds of Potamogeton americanus in Spen-
cer Lake the species occurs in great abundance. At an earlier date
Professor Comstock found the larve abundantly among the
aquatic vegetation at the north end of Cayuga Lake. During
recent years, however, it has been impossible to find a single speci-
men in this situation.

Hasits.—In Spencer Lake the larve feed on Potamogeton
americanus. On this plant they, with their brilliant green color
showing through their transparent cases, can hardly be distin-
guished from the stipules of the leaves of their food plant, which
they resemble exactly in size and form.

Vorhies experienced great difficulty in distinguishing the larve
from the spine-like leaves of Ceratophyllum, on which he found
them common in Wisconsin.

Before pupation one side of the cephalic end of the case is
made fast to the host plant, leaving the case projecting in a de-
cidedly spine-like manner. The pupa, like the larva, is brilliant
green and shows its color distinctly through the transparent case.

102

LEPTOCERID.

The peculiar curved form of the tibia and basal tarsal joint
of the middle leg indicates some peculiar habit in the larval life
of this species.

PERIOD OF EMERGING.—Our earliest record of emerging is
June 2oth. At that time most specimens had pupated, but a few
were still in the prepupal state. These late specimens would
probably emerge about the middle of July.

DIsTINCTIVE CHARACTERS OF Larva.—Color light-green in
life. Length, 9 mm. Tarsus of middle leg curved, figure 179.
Swimming hairs on hind legs.

SETODES GRANDIS.

176. Larva. Head and thorax. 179. Middle leg.
177. Larva. Frons. 180. Larva. Hind leg.
178. Front leg. 181. Case.

Head.—The ground color of the head is pale straw yellow;
on the dorsal surface it is spotted with dark-brown, as in figure
176; the ventral surface is without marks. ‘The mandibles are
deeply grooved, and have several teeth on the inner surface; in
color they are brown.

The Thorax—The prothorax is straw yellow, mottled with
oval brown spots, as in figure 176.

103

NORTH AMERICAN CADDIS-FLY LARVE.

On the mesothorax the dorsal plates are straw yellow, with a
few dark oval spots.

The metathorax is without chitinous plates.

The legs are illustrated in figures 178, 179, and 180. On the
middle leg the tarsal claw is forked near its tip; the basal joint is
slightly curved and is armed with about five thorns on its inner
surface. he tibia is slightly curved and is armed with several
prominent thorns on its inner surface. There is no indication of
a suture in its femur.

The hind leg has numerous long swimming hairs. The short
basal segment of the femur is well marked. The trochanter is
divided into a short basal and long apical piece.

The Abdomen.—Gills are absent on this species, though they
are present on the species of the genus in the European fauna.

DESCRIPTION OF THE Case.—The case has the form of an elon-
gate cone. It is made of pale yellow transparent silk, through
which the color and form of the bright green larva or pupa can
be distinctly seen. Under a lens the separate strands of silk can
be plainly seen, wound in spiral form like the leaf fragments in
the case of Triznodes.

The case of the pupa, figure 181, has a convex disc of silk
across its cephalic end. In the center of this disc there is a small
circular opening. At the caudal end of the pupa’s body, about
one third from the caudal end of the,case, there is a strongly con-
vex partition of silk with a comparatively large circular opening
in its center. Through this opening the caudal appendages of the
pupa sometimes project, and through it the cast skin of the last
larval molt is eliminated.

FAMILY MOLANNID-.

In the American fauna only the genus Molanna has known im-
mature stages.

DESCRIPTION OF THE LARva:.—The gula is subquadrate, widely
separating the pleure. The pronotum and mesonotum are chiti-
nized, the metanotum membranous. The prosternal horn is lack-
ing. All three spacing-humps are present on the first abdominal
segment.

104

MOLANNIDE.

GENUS MOLANNA.

Hasitat.—Larve of the genus Molanna were found in the
sand of a small stream in the McLean swamp. Unfortunately the

183

MOLANNA SP.
182. Case. 183. Larva. Front leg.

alcohol evaporated from the bottle of preserved specimens, leav-
ing the larve worthless, but the cases did not deteriorate.

Adults of the genus are not uncommon near Cayuga Lake,
from which they probably emerge.

Hasits.—The larve observed were neatly nestled in the sand
of the stream’s bottom, where the wings of their cases blended so
perfectly with the surrounding sand that they were most difficult
to detect. Probably the genus would be found not uncommon if
the cases could be more easily seen.

Tue Larv#.—Molanna is the only American genus of the
subfamily Molanninz, which can readily be distinguished by the
spur of the middle and front tibia. In Molannine the spur arises
on a distinct prominence, while in the subfamily Berzinz the prom-
inence is entirely absent. Figure 183 represents the front leg
of Molanna uniophila, furnished by Mr. Vorhies.

105

NORTH AMERICAN CADDIS-FLY LARV.

FAMILY HYDROPSYCHID.

The family is divided into two subfamilies. The Macronema-
tine are abundant in the Great Lake region, but have not been
found in the vicinity of Ithaca. Their larve probably live in
large lakes and slow-moving rivers. As yet there is no published
account of their immature stages.

The subfamily Hydropsychine is represented in our fauna by
a few species belonging to three genera. These have been care-
fully studied by Miss Alice Noyes and have been recorded by her
in 1917, and in the manuscript of a forthcoming paper. The
present account of the larvae is condensed from the work of Miss
Noyes.

Hasits.—The habits of our three genera of Hydropsychine
differ one from another only in minor details. The best-known
species are recorded in the genus Hydropsyche, but probably most
authors have not made generic determinations within the family.
Hydropsychid larve dwell only in swift-flowing waters and on the
wave-beaten shores of lakes. In these situations they occur in
vast numbers. Miss Noyes seems to have found it not uncommon
to find as many as 165 larve on a square of the stream’s bottom
measuring only 8% x 8% inches. The larve are most abundant
on the exposed surfaces of stones, ledges, and even on the brinks
of falls. In these situations they build the characteristic nets that
are so well known in the literature on entomology. The nets,
typically, have a semicircular opening facing upstream. From
this opening the net extends back in bag-like form. The front
end is made of fine silk, strengthened by irregular coarse strands.
Behind the fine-meshed front margin there is an area of coarser
mesh that acts as a seine. It is made of tough strands running
in two directions, forming a mesh of minute squares, through
which the water passes while straining out its burden of plancton
and small insects. The larva lives in a silken tube at one end of
the seine. From this retreat it can freely enter the trap to feed
upon its catch of aquatic organisms.

Foop or THE Larv.—Young larve feed upon green and blue-
green alge. In later life they change their diet to include also
diatoms and various vegetable plancton, as well as Ostracods and

106

HYDROPSYCHIDEH. PSYCHOMYIDE.

the larve of aquatic insects, such as mayfly nymphs and the larve
of Chironomids.

In eating the insects the larve do not chew their victims, but
grasp them with their fore legs and thrust them bodily into their
alimentary cavity.

DESCRIPTION OF THE LARVaA.—The head is small. On the
inner margin of the left mandible there is a tuft of bristles. The
labrum is entirely chitinized.

All three thoracic segments bear dorsal chitinous plates. The
prosternal horn is lacking. Branched gills are present on the meso-
and meta-thorax.

The abdomen bears branched external gills and retractile rectal
gills. Spacing-humps and the lateral fringe are lacking. There
is no chitinous shield on the dorsal surface of the ninth segment,
but the ventral surfaces of the eighth and ninth segments bear
chitinous plates. Each proleg is armed with a tuft of long bristles
slightly above the claw.

FAMILY PSYCHOMYID.

The family includes only four genera and about thirty-five
species. Of these all are confined to Europe, except a half-dozen
species belonging to two genera, which occur in North America.
The life histories of none of the North American species have
been published.

DESCRIPTION OF THE Larva:.—Head, prothorax, and the last
abdominal segment smaller than the rest of the body. Head com-
pressed. Mandibles asymmetrical, the left with two teeth on the
inner margin, and with a thick brush of hairs in the groove; the
right mandibles lacks teeth on the inner margin, and lacks a brush
in the groove. On the thorax the pronotum alone bears a chi-
tinous plate. The prosternal horn is lacking.

The Europearr species of the family make no portable cases,
but live on stones in long, loosely-spun galleries of silk and sand
grains. They are found mostly in swift water, but also inhabit
ponds and lakes.

107

NORTH AMERICAN CADDIS-FLY LARV.

FAMILY POLYCENTROPIDE.

Haprtrat.—The larve are common insects in all swift streams
of the region, and in many situations of standing and slow-mov-
ing water.

Hasits.—In the swift streams about Ithaca several genera
live among the rocks, making nets of different form. The habits
of these have been described by Miss Noyes, 1914.

Several species of the genus Phylocentropus live in still or
slowly-flowing water with sandy or muck bottoms. These larvae
spin subterranean tubes of silk, which sometimes reach ten centi-
meters in length. Often the tubes have one or mére branches, and .
always they contain a bulbous swelling near the middle in which
the larva probably rests, and in which pupation takes place. In
natural position the tubes are beneath the ground, except about
half an inch which projects upward into the water.

In summer, when the water recedes, it is not uncommon to
find the exposed muck margins of upland swamp streams broken
by innumerable quantities of these Phylocentropus chimneys, pro-
jecting upward into the air.

The genus offers an interesting field for future study to ascer-
tain how the larva lives and feeds within its tube; how it uses its
long, needle-like labium in spinning, and what particular use is
made of its peculiar mandibles, legs, and other characteristic
structures.

Foop oF THE Larva:.—The larve of the species that have been
studied feed upon plancton organisms and small insects that be-
come entrapped in the mesh of their tubes.

DESCRIPTION OF THE LARVA:.—The frons extends back to the
caudal margin of the head, completely separating the epicrania.
The labrum is entirely chitinized. The pronotum is chitinized,
the meso- and meta-nota are soft.* Spacing-humps, the prosternal
horn, the lateral fringe, and external gills are absent. There is no
chitinous shield on the dorsal surface of the last abdominal seg-
ment. The prolegs are long, and are not fused on the median
line to form an apparent tenth segment.

*In an exotic subfamily all three thoracic segments are chitinized
dorsally.
108

POLYCENTROPIDA. PHILOPOTAMIDE.

FAMILY PHILOPOTAMIDE.

The larve are common in most swift streams of the region.

Among the stones of the bottom, where the force of the cur-
rent is broken, they spin delicate nets of fine silk. In form the
nets resemble the finger of a glove, attached at the open end, which
is directed upstream, and free at the closed end. In the closed
end of the net there is a small slit, just large enough to allow the
escape of the larva in case of danger. The nets are 25—4o mm.
in length and 3—4 mm. in breadth. They often occur in great
numbers, completely covering the stones with a thin flocculent
mass of dirty silk.

Though these nets cannot stand the full flow of the unbroken
current, it is necessary that they be situated where there is enough
flow of water to keep them distended. On lifting a net-covered
stone from the water the nets invariably collapse, appearing as
a mass of diatomaceous ooze through which the larve rapidly
wriggle backward.

While the nets of the Philopotamid larve serve as hiding-
places, their principal function is to serve as sieves through which
the flowing water is strained ; the larve feeding on the microscopic
organic particles that are entangled in the mesh.

Description oF Larva:.—In color the larve are orange or
yellow. The head is compressed; the labrum is entirely mem-
branous; the cephalic margin of the frons is asymmetrical; the
mandibles are asymmetrical, without tufts or bristles. The pro-
thorax is the only thoracic segment that is chitinized dorsally.
The abdomen has but few long hairs; the prolegs have but two
long and two short bristles, slightly above the drag-hooks; gills,
spacing-humps and lateral fringe are lacking.

DEscRIPTION OF THE CasE.—Until nearly time for pupation
the larve build the silken nets previously described. Before pupa-
tion they cover themselves with a rather irregular dome of pebbles,
between which respiratory aperatures are left.

A careful study of the habits of the larvae was made by Miss
Alice Noyes, 1914, followed by a more detailed study with de-
scriptions of the immature stages, the results of which are as
yet in manuscript. On the results of this work the present account
of the family and key to the species are based.

109

NORTH AMERICAN CADDIS-FLY LARVZ.

Key To LArva PHILOPOTAMID2.

A. Anterior margin of femur without a spur terminated by a
bristle, anterior margin of clypeus but slightly indented.
Lateral lobes of labrum but slightly developed.—Philopota-
mus distinctus (?)

A.A. Anterior margin of femur with spur terminated by a bris-
tle, anterior margin of clypeus deeply indented. Lateral
lobes of labrum well developed. Chimarrha.

B. Larva orange. Anterior margin of clypeus with deeper and
more angular incision —C. aterrima.

B.B. Larva pale yellow. Anterior margin of clypeus with shal-
lower and more curved incision.—C. socia.

FAMILY RHYACOPHILIDA:.

Hapitat.—Rhyacophilid larve are fitted for life only in flow-
ing water. Representatives of the family may be found in all of
our streams that flow over a stony bottom and that do not go
entirely dry during any part of the year.

Hasits.—Members of the two subfamilies differ widely in
their larval habits. Members of the subfamily Rhyacophiline
build no cases until the prepupal stage is reached. They crawl
actively under or between stones, obtaining a firm hold on their
support with their well-developed drag-hooks and legs. They are
active larve that easily crawl about without the protection of a
case. When their activity is about to cease for pupation, they
build a strong fence of stones about themselves and in its protec-
tion undergo pupation.

Members of the subfamily Glossosomatine build cases of sand
grains or pebbles. With their cases they crawl slowly over the
exposed surfaces of stones. They are sluggish larve that cannot
exist without the protection of a case. Pupation takes place on
the exposed surfaces of stones, within their cases of sand.

Before pupation members of both subfamilies spin a sheet of
silk closely about themselves. This silken cocoon has a strong
superficial resemblance to the puparia of the higher Diptera. The
silk of the cocoon is rubber-like in appearance, and even under the
microscope shows no texture whatever, and no openings for
transpiration of water are apparent. If taken from water and

IIo

RHYACOPHILID&.

dropped into strong alcohol the cocoon collapses, giving additional
evidence that it contains no openings.

Foop.—The Rhyacophiline sometimes eat filamentous alge,
but show a preference for small larve. The larve are taken into
the stomach entire, without any chewing or mutilation.

The food of the Glossosomatine is not known. Stomachs ex-
amined contained a structureless material that could not be identi-

fied.

EMERGENCE.—Some species emerge throughout the entire
summer, while the transformation of others is restricted to a short
period.

Description oF Larva‘.—The abdomen consists of nine seg-
ments; the prolegs are not fused to form an apparent tenth seg-
ment. Spacing-humps, prosternal horn, and lateral fringe are ab-
sent ; external gills are absent on all known American species, but
occur on some European species; rectal gills are present on some,
perhaps all, species, but are usually retracted and not easily seen;
the abdomen is but little wider than the thorax.

Key To THE LARVA: OF RHYACOPHILIDA.
A. Drag-hooks plainly more than half as long as last abdominal
segment. Without transportable cases—kKhyacophiline.
A.A. Drag-hooks plainly less than half as long as last abdominal
segment. Larve with transportable cases—Glossosoma-
tine.
SUB-FAMILY RHYACOPHILIN#.

Description oF Larvas.—The head is long and flattened,
truncate at the cephalic margin. The abdomen is depressed, with
deep constrictions at the sutures; the prolegs are well developed,
and extend parallel to the axis of the body; their claws are long.
The maxillary lobes are long and slender.

RHYACOPHILIN-E.

A. Apparently two pairs of well-developed drag-hooks. Con-
spicuous dark-brown pattern passes transversely across
middle of head—Rhyacophila fuscula.

A.A. Apparently but a single pair of well-developed drag-hooks.
No transverse pattern across middle of head.—Rhyacophila
torva.

III

NORTH AMERICAN CADDIS-FLY LARVE.

RHYACHOPHILA FUSCULA.

LarvaL Hasrrat.—The species is common throughout the
region in all fast-running streams with stony bottoms. They are
numerous in the permanent streams on the upland hills, but are
far more common in the stony gorges near the lake’s level.

LarvaL Hasitat.—Until the prepupal state is reached the
larve build no cases, but crawl naked beneath the stones of the
stream’s bottom. For life in this situation the flat body and wedge-
like head of the larve are well adapted, and any form of portable
case would be an incumbrance that would make its mode of life
impossible.

Foop or LArv4.—Examinations of stomachs indicate that the
larve live on a mixed diet of animal and vegetable food, with
animal material taken in greatest abundance. Only one stomach
examined contained nearly pure contents of the filamentous algz,
Cladophora. Two stomachs contained a little Cladophora mixed
with Chironomid larve; and six stomachs contained nothing but
Chironomid larve. In all cases where Chironomid larve were
found they were swallowed whole, with no mastication whatever.

PrepupaL Hasits.—In preparing to pupate the larva makes
the first case of its life—not a portable or close-fitting case like
those made by most Trichopterous larve, but a roomy corral-like
inclosure of pebbles. Inside of the corral the larva spins a pu-
parium-like sheet of silk closely about itself. Within this case
transformation takes place.

Preriop OF EMERGING.—Specimens were taken on the wing
from the latter part of May until the middle,of July. It is probable,
however, that more careful collecting will discover adults emerg-
ing during the greater part of the summer.

DeEscripTION oF LaArvA.—Length, 20 mm. Color in life, dark-
green, changing to brown in alcoholic specimens.

The Head.—The ground color is straw yellow, with dark-
brown markings subject to slight variation, figure 184. Behind
each eye there is an elongate subcutaneous mark of jet black;
at the caudal margin of each side. of the head there is a jet black
mark. On the ventral surface the head is straw yellow, except

112

-RHYACOPHILIDA.

bordering the mouth parts, where it shades into brown. The
mandibles are black and differ in form, as in figure 185. The
labrum is small and is very weakly chitinized.

RHYACOPHILA FUSCULA.

184. Larva. Head and thorax. 187. Larva. Prolegs, ventral view.
185. Larva. Mandibles. 188. Larva. Frons.
186. Larva. Drag-hook. 189. Larva. Prolegs, lateral view.

The Thorax.—tThe chitinous dorsum of the prothorax is straw
yellow, marked with dark-brown, as in figure 184. Each epister-
num is extenuated forward into an upturned spine-like projection
which bears a seta at its tip. The ventral surface is free from
chitinous plates and is without a horn.

On the meso- and meta-thorax dorsal chitinous plates are lack-
ing. The pleural sutures are deeply sunken, giving a bulbous
form to the bordering integument above the bases of the coxe.

The Abdomen.—The abdomen is somewhat flattened and the
sutures are deeply constricted, giving a decidedly corrugated ap-
pearance. External gills are entirely absent—spacing-humps and
lateral fringe are lacking. The drag-hooks are well developed ;
each movable claw, figure 186, has three teeth and two prominent
sete on its lower surface; above the claw just back of the hinge
there is an obtuse chitinous projection, figure 189, and at the base
of each proleg there is a long rapier-like projection, figure 189;

8 113

NORTH AMERICAN CADDIS-FLY LARVZ.

on the under side of the proleg near the base there is a chitinous
hook directed backward, figures 187, 189.

In a few of the alcoholic specimens examined there are finger-
like anal gills. It seems probable that anal gills are constant in
the species, but are protruded in preserved specimens only under
exceptional conditions.

Tue Case.—As previously stated, the larva makes no case until
it begins to prepare for pupation. It then crawls within some
crevice between large stones and builds a fence-like wall of peb-
bles about itself. The fence is oval in outline and is many times
larger than the body of the insect. Inside its inclosure the larva
spins about itself a close-fitting, parchment-like sheet of silk,
superficially resembling the puparium of the higher Diptera.
Here transformation takes place.

RHYACOPHILA TORVA.

LarvaL Hasirat.—The half-dozen larvae which have been
collected in the region were taken in three of the nearby gorges
leading into the Cayuga Lake Valley. The large number of adults
occurring in all of the gorges indicates that the species is a com-
mon one in the swift waters of the region.

LarvaL Hasirs.—When collected our specimens were not dis-
tinguished from R. fuscula, which the species probably closely re-
sembles in habits.

PrepupaAL Hasits.—The prepual habits of the species were
not observed.

Preriop oF EMERGING.—Adults are on the wing during the
month of June.

DEscRIPTION OF Larva.—Length, 20 mm. Head, long and
flat, with parallel sides.

The Head.—The color of the head is straw yellow, shading
into brown behind the mouth parts; behind each eye there is a
jet black subcuticular mark, and the caudal margin is narrowly
bordered with black, figure 190. The labrum is very weakly chi-
tinized ; both mandibles have long teeth, much more deeply notched
than those of R. fuscula; the mandible of the left side is broader
than that of the right side.

114

RHYACOPHILID&.

The Thorax—The prothorax above is straw yellow, with a
caudal margin of deep black; each episternum is extended for-
ward in a spine-like process which has a black dorsal spot; the
legs are straw yellow.

RHYACOPHILA TORVA.

190. Larva. Head and thorax. 192. Larva. Prolegs, lateral view.
191. Larva. Frons.

The meso- and meta-thorax are brown in alcoholic material,
marked with light yellow, as in figure 190; the second and third
pairs of legs are almost white.

The Abdomen.—The abdomen is narrower and less flattened
than that of R. fuscula, the constrictions between segments are not
quite so deep, and dorsal furrows of the integument are absent.
Each segment has a similar dorsal pattern of light color, as shown
in figure 190. The drag-hooks, figure 192, are slender and very
simple compared to those of R. fuscula; there are no lateral spine-
like elongations of the chitin, no dorsal humps at the base of the
claws, and no ventral back-turned hooks. The drag-hooks are
long and slender and comparatively weak.

DrscrIPTION OF CasE.—We have made no observations on
the case-building habits of the species. Vorhies, who reared it in
Wisconsin, states that “the larva lives in a loosely-built case of
gravel,” and “at the time of pupation this becomes a strong, irregu-

II5

&

NORTH AMERICAN CADDIS-FLY LARVZE.

lar hemi-ellipsoid, measuring 10 mm. wide by 15 mm. long.” In
our collection a single specimen in the prepupal state is inclosed
in a puparium-like sheet of silk, like that made by R. fuscula.

SUB-FAMILY GLOSSOSOMATIN&.

DeEscrIPTION oF LArva.—The head is rounded, not long and
flattened. The abdomen is round in cross-section, with normal
inter-segmental constrictions. The prolegs are short and extend
at right angles to the long axis of the body; their claws are weak.
The maxillary lobes are short and broad.

GLOSSOSOMATIN A.

A. Meso- and meta-notum each with a pair of chitinous plates.—
Agapetus.
A.A. Meso- and meta-notum entirely soft—Glossosoma.

GLOSSOSOMA AMERICANUM.

LarvaL Hapitat.—The larve are found in all swift waters of
the region, but reach their greatest abundance in the riffles of the
upland streams. In the parts of streams with stony bottoms in the
McLean and Freeville swamps the larve occur in extraordinary
abundance, their cases completely covering the sides of nearly
all submerged stones.

LarvaL Hasrts.—From the time of hatching until the pre-
pupal stage the larve live singly on the stones of the stream’s
bottom. Before pupating they congregate in dense colonies on
the sides and bottom of stones, with their cases placed edge to
edge—sometimes one on top of another. It is during this prepupal
stage that the larve are most often encountered.

Foop oF Larva:.—Stomachs of a large number of specimens
were examined. All contained a light-colored material, the cellu-
lar nature of which could not be determined.

PrEPUPAL Hasits.—In the prepupal state the larve develop
a gregarious habit—large numbers congregating in small areas.
At this time the floor of the case is cut away and the entire rim
of the cup-like roof is securely glued to some solid support. Under
this cover the puparium-like cover is spun around the larva.
116

RHYACOPHILIDE.

Periop oF EMERGING.—The species is found as larve, pupee,
and adults during the entire summer.

DEscRIPTION OF Larva.—Length, 9 mm. In cross-section
the body is round. It assumes a curved position, especially marked
toward the caudal end of the abdomen.

GLOSSOSOMA AMERICANUM.

193. Larva. Head and thorax. 196. Case of larva, dorsal view.
194. Larva. Frons. 197. Case of larva, ventral view.
195. Larva. Mandible.

Head.—The head is small compared to the thoracic segments.
It is light-brown without a pattern, except a light-colored area
around each eye and indistinct muscle-attachment marks. The
mandibles, figure 195, are alike; each has a sparse fringe of pale
hairs on its inner margin; in color they are brown. The labrum
is shown at the base, with pale outer margins which bear numerous
short, light-colored hairs.

Thorax.—The prothorax, figure 193, is heavily chitinized
above; it is nearly uniform brown in color; on the ventral side
there is a brown chitinous plate covering the entire lower surface
of the segment; the horn is absent.

The meso- and meta-thorax are without chitinous dorsal plates.

117

NORTH AMERICAN CADDIS-FLY LARVE.

Each of these segments bears an indistinct pattern of pale, narrow
marks on its soft dorsal surface.

Abdomen.—The abdomen is without external gills. The pro-
legs are turned at right angles to the axis of the body, and bear
drag-hooks of extremely small size, which are apparently put to
but little use.

Description oF CasE.—The case of the larva, figures 196, 197,
is made of small pebbles or large sand grains. In form it appears
much like a diminutive turtle. On the lower side, figure 197, there
is a floor of sand grains built across the middle of the case, leaving
the two ends open on the bottom, but completely covered on the
upper surface. This case is freely movable over the surface of
rocks.

The case of the pupa differs from the case of the larva only in
having no floor. The rim of the case is tightly cemented to some
submerged rock, and inside of the inverted cup thus formed the
cocoon is spun and pupation takes place.

GENUS AGAPETUS.

An unreared species of the subfamily Glossosomatine, which
agrees well with published European descriptions of the genus
Agapetus, was collected in Michigan Stream above Spencer Lake.

The larve differ from the larve of the genus Glossosoma in
having a pair of large chitinous shields on the mesothorax and a
pair of smaller shields on the metathorax. The prolegs and drag-
hooks are larger than those of Glossosoma.

The cases are similar to those made by Glossosoma, but larger
pieces of gravel are used in their construction.

FAMILY HYDROPTILID:.

This family contains the most minute members of the order
Trichoptera. For this reason, no doubt, it is the most neglected
family in the order. Scarcely the first step has been taken toward
a knowledge of the immature stages in America, and even the
adults are most imperfectly known. In the present stage of our
knowledge no attempt at classification is possible.

The tiny larve inhabit standing or flowing waters, and often
occur in very great numbers. Often their cases completely cover

118

HYDROPTILID&.

the edges of rocks in swift streams, or hang in masses in waving
tufts of Cladophora.

The cases of the described species are all portable, except those
of Ithytrichia confusa, which is tightly cemented to rocks in mov-
ing water. The cases vary greatly in form in different species.
For the most part they are made of pure silk, but some have a
sparse interweaving of sand grains or filaments of green alge.

DescRIPTION OF THE Larva:.—The mandibles are asymmet-
rical. The antenne are large, almost as long as the mandibles.
Each thoracic segment bears a four-cornered shield. The pro-
sternal horn is lacking. The middle of the abdomen is much larger
than the thorax; spacing-humps are absent. The dorsal surface
of the abdominal segments often bears chitinous plates. The pro-
legs are short, with short, stout claws.

The chitinous armature of the larve offers excellent char-
acters for classification which, together with the interesting habits
of the species, offers a promising field for future investigation.

11g

BIBLIOGRAPHY.

A complete bibliography of the writings on the order Trichop-
tera is far beyond the scope of the present work. For more com-
plete references to the literature the student is referred to “Die
Trichopteren-Literatur von 1903 (resp. 1907), bis Ende 1909,”
by Georg Ulmer, Zeitschrift ftir wissenschaftliche Insektenbi-
ologie, 1911 and 1912. This work reviews all writings on the
order that appeared during the period between 1903 and Igog.

A more lengthy bibliography of the Trichoptera of the world
appears in ‘Genera Insectorum,” Ulmer, 1907.

Bibliographical references to the adults of the American fauna
will be found in “Catalogue of the Neuropteroid Insects of the
United States,” by Nathan Banks, American Entomological So-
ciety, 1907.

A bibliography of the more important works is contained in
“Studies on the Trichoptera of Wisconsin,” by Charles T. Vor-
hies, Transactions of the Wisconsin Academy of Sciences, Arts,
and Letters, 1909.

The most important key to the North American Trichopterous
larve, Krafka, 1915, is quite satisfactory for determining most
species to the family or subfamily, but makes no attempt to classify
genera and species.

A number of authors have published more or less on the habits
of caddis-worms. No doubt the most important of these is the
work of Dr. Vorhies, 1909, in which are described the immature
stages of nineteen species, with careful notes on their habits.

Preceding the work of Dr. Vorhies, Miss Cora H. Clarke
published two articles, 1882 and 1901, in which she described and
figured the cases of more than twenty species. Many of the de-
terminations in this article go no farther than the genus, and
sometimes no attempt at classification is made. The figures of
the cases are good and many accurate notes on the habits of the
larve accompany them. That the author used more than usual
care in observing her specimens is shown by her figure of the
respiratory grating of the case of Neophylax (unnamed in her
article) and her mention of the “spinnaret” of the larva ‘‘Plec-
tronemia.” Without doubt this was a species of Phylocentropus.

120

_ BIBLIOGRAPHY.

There are no more accurate figures and notes on the cases of the
larve and pupe of Trichoptera than are furnished by the work
of Miss Clarke.

The habits of the net-spinning caddis-worms of swift water
have been carefully described by Miss Noyes, 1914. A more
detailed account of the net-spinners, together with a description
of the larvee and pupz, has been prepared by Miss Noyes and is
forthcoming in a bulletin of the New York State Museum.

Dr. Cornelius Betten has prepared a careful monograph of all
stages of North American Trichoptera, which will soon appear as
a bulletin of the New York State Museum. After the appearance
of this work much of the difficulty of determining species will be
removed and, no doubt, the study of the order will be greatly
stimulated.

The bibliographical references in this paper cover all of the
important writings on the immature stages of North American
Trichoptera known to us. Many excellent papers have appeared
on the immature stages of the European species, reference to
which will be found in the aforenamed bibliographies. Much use
has been made of many of these works in the preparation of the
present paper, especially to the part on Trichoptera, Heft 5/6,
of the “Stisswasserfauna Deutchlands,” by Georg Ulmer.

A List oF THE More ImMporTANT WRITINGS ON THE IMMATURE STAGES OF
NortH AMERICAN TRICHOPTERA.

Berren, C. 1901. Aquatic Insects of the Adirondacks. Bull. 47. N. Y.
State Mus. pp. 561-172.

Berren, C. 1902. The Larva of the Caddis-fly, Molanna cinerea. Jour.
N. Y. Ent. Soc. X. pp. 147-154.

CiarKE, Cora H. 1882. Descriptions of two interesting Houses made
by native Caddis-fly larvae. Proc. Bost. Soc. Nat. His. XXII. pp.
67-71.

Crarkr, Cora H. 1891. Caddis-worms of Stony Brook. Psyche. VI.
Pp. 153-158.

Comsrocx, Anna B. 1903. Ways of the Six-Footed. Boston. pp. 133-138.

Comstock, J. H. 1901. Insect Life. New York. pp. 79-80, 148-152.

Comstock, J. H. 1901. On the Emergence of a Caddis-fly from the water.
Am. Nat. XXI. p. 480.

Comstock, J. H. 1899. Manual for the Study of Insects. Ithaca. pp.
186-190. ;

I21

BIBLIOGRAPHY.

Fievpe, A. M. 1887. On an Aquatic Larva and its Case. Proc. Acad.
Nat. Sci. Phil. p. 293.

Hit-Grirrin, Annie Laura. 1912. New Oregon Trichoptera. Ent. News.
XXII. pp. 17-21.

Howarp, L. O. The Insect Book. New York. pp. 195-205.

Hovucuron, W. 1868. Caddis-worms and their Metamorphosis. Pop. Sci.
Rey. VII. pp. 287-295.

Kettocc, Vernon L. 1905. American Insects. New York. pp. 240-245.

KrarKa, Joseph Jr. 1915. A Key to the Families of Trichopterous Lar-
vae. Can. Ent. XLVI. pp. 217-225.

Luoyp, J. T. 1915a. Notes on Brachycentrus nigrisoma. Banks. Pomona
Jour. Ent. & Zool. VII. pp. 81-86.

Luoyp, J. T. 1915b. Notes on the Immature Stages of some New York
Trichoptera. Jour. N. Y. Ent. Soc. XXIII. pp. 201-212. 6
Luoyp, J. T. 1915c. Wood-boring Trichoptera. Psyche. XXII. pp. 17-21.
Luoyp, J. T 915d. Notes on Ithytrichia confusa Morton. Can, Ent.

XLVII. pp. 117-121.

Luoyp, J. T. 1915e. Notes on Astenophylax argus Harris. Jour. N. Y.
Ent. Soc. XXIII. pp. 57-60.

MarsHAL., W. S. & Voruies, C. T. 1905. The repair and rebuilding of
the larval cases of Platyphylax designatus. Walk. Biol. Bull. IX.
pp. 232-244.

MarsHat, W. S. & Voruts, C. T. 1906. Cytological studies on the Spin-
ning Glands of Platyphylax designatus Walker. Intern. Monatschr.
f. Anat. u. Physiol. XXIII.

MarsHALL, W. S. 1907. The early history of the cellular elements of the
ovary of a Phryganid. Platyphylax designatus Walk. Ztschr. wiss.
Zool. LXXXVI. pp. 214-237.

Murpuy, Helen E. 1919. Observations on the Egg Laying of the Caddis-
Fly Brachycentrus nigrisoma Banks, and on the habits of the young
larvae Jour. N. Y. Ent. Soc. XXVII. pp. 154-159.

NAKAHARA, W. 1917. On the Physiology of the Nucleoli as seen in the
Silk-Gland Cells of certain Insects. Jour. Morph. XXIX. pp. 55-68.

NeEepHAM, J. G. 1903. Aquatic Insects in New York State. N. Y. State
Mus. Bull. LXVIII. pp. 205-206.

NeEEpHAM, J. G. 1903. Remarks on Hydroptilid larvae and their Meta-
morphosis. Zool. Anz. XXVII. pp. 108-110.

NeepHAM, J. G. 1908. Report on the Entomological Field Station con-
ducted at Old Forge, N. Y., in the summer of 1905. N. Y. State
Mus. Bull. CXXIV. pp. 12, 14.

NEEDHAM, J. G. & Lioyn, J. T. 1015. The Life of Inland Waters. Ithaca.
pp. 260-261, 214-218, 371-372.

Noyrs, Alice Ayr. 1914. The Biology of Net-Spinning Trichoptera of
Cascadilla Creek. Annals Ent. Soc. Am. VII. pp. 251-272.

I22

BIBLIOGRAPHY.

Noyes, Alice Ayr. 1915. The Proventriculus of a Hydropsyche larva.
Jour. Ent. & Zool. VII, pp. 34-44.

SHeELForD, Victor E. 1913. Animal Communities in Temperate America
as illustrated in the Chicago Region. Geog. Soc. Chicago Bull. V.
(Numerous brief references).

Simpson, C. B. 1903. The Log-Cabin Builder (Limnephilus indivisus
Walk.). Proc. Ent. Soc. Wash. V. pp. 98-100.

Simpson, C. B. 1903. Photographing nets of Hydropsyche. Proc. Ent.
Soc. Wash. V. pp. 93-94.

Stetcut, Charles E. Relations of Trichoptera to their Environment.
Jour. N. Y. Ent. Soc. XXI. pp. 4-8.

Vorutrs, C. T. 1905. Habits and Anatomy of the Larva of the Caddis-
fly. Platyphylax designatus Walker. Trans. Wisc. Acad. Sci. Arts.
Letters. XV. pp. 108-123.

Vorutes, C. T. 1908. The development of the nuclei of the spinning gland
cells of Platyphylax designatus Walker. Biol. Bull. XV. pp. 54-62.

Vorutrs, C. T. 1909. Studies of the Trichoptera of Wisconsin. Trans.
Wisc. Acad. Sci. Arts. Letters. XVI. pp. 647-738.

Vorutres, C. T. 1913. Trichoptera collected under unusual conditions.
Ent. News. XXIV. p. 84.

Specific descriptions of the following North American larve
have appeared in previous publications. (*) Indicates species also
described in the present work.

SPECIES. AUTHOR. SPECIES. AUTHOR.
Astenophylax = Lloyd. Hydropsyche Vorhies.
argus* 19gtse. p. 57- alternans 1909. p. 707.
Brachycentrus Lloyd. Ithytrichia Lloyd.
nigrisoma* 1oisa. p. 81. confusa 1g15d. p. 117.

Murphy.
1919. p. 154. Lepidostoma Vorhies.

wisconsinensis 1915. p. 685.

Chilostigma Lloyd.

difficilis* I9I5b. p. 208. Leptocella Vorhies.
uwarowii IQI5. p. 605.
Ganonema Lloyd.
nigrum —* IgIsc. p. 17. Leptocerus Vorhies.
(americanum ?) ancylys* IQI5. p. 691.
Grammataulius Hill-Griffin. Leptocerus Vorhies.
bettenii 19i2. p. 18. dilutus I9I5. p. 688.
Helicopsyche Vorhies. Leptocerus Vorhies.
borealis* 1909. p. 681. tarsi-punctatus I9I5. p. 604.

123

BIBLIOGRAPHY.

SPECIES.

Limnophilus
combinatus =*

(rhombicus)
Limnophilus
indivisus

Limnophilus
submonifer*

Molanna
cinerea

Molanna
uniophila

Mystacides
alafimbriata

Neophylax
automnus*

Neuronia
pardalis*

AUTHOR.
Vorhies.
1909. p. 661.
Lloyd.

I915b. p. 203.
Lloyd.

1915b. p. 205.
Vorhies.
1909. p. 666.
Betten.

190I. p. 564.
1902. p. 147.
Vorhies.
1909. p. 705.
Hill-Griffin.
1912. p. 19.
Vorhies.
1909. p. 660.
Lloyd.

I9g15b. p. 201.

124

SPECIES, AUTHOR.
Neuronia Vorhies.
postica* 1909. p. 658.
Phryganea Vorhies.
interrrupta* 1909. p. 654.
Phylocentropus Vorhies.
maximus 1909. p. 7II.
Phylocentropus Betten.
lucidus IQOI. p. 565.
Platyphylax Vorhies.
designatus* 1905. p. 108.

1909. p. 672.
Platyphylax Vorhies.
subfasciatus 1909. p. 678.
Rhyacophila Vorhies.
torva* 1909. p. 713.
Setodes Vorhies.
grandis* 1909. p. 699.
Triaenodes Vorhies.
flavescens 1909. p. 702.

Publications Issued by The Lloyd Library—Continued.

Repropuction Series No. 7, sy Joun Uri Luovp.
Life and medical discoveries of Samuel Thomson and a history of the
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Puarmacy Series No, 2, sy Joun Uri Lroyp.
The Eclectic Alkaloids; Resins, Resinoids, Oleo-Resins, and Con-
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Mycotocreau Series No. 4.
Synopsis of the Known Phalloids, by C. G. Lloyd.

Mycotocicat Sertes No. 5.
Synopsis of the Genus Hexagona, by C. G. Lloyd.

Botany Series No. 1.
Catalogue of the Ferns and Flowering Plants of Cincinnati, Ohio,
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Borany Series No. 2, py Atrrep J. Morrison, Pu. D.

Reise durch einige der mittlern und sudlichen vereinigten Nordameri-
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Erlangen, bey Johann Jacob Palm, 1788.

Puarmacy Series No. 3, py Proressor L. E. Sayre.

_ Gelsemium. A study that embodies the recent work of Prof. L. E.
Sayre, Lawrence, Kansas, together with fragments of a paper read
by him before the American Pharmaceutical Association, Richmond,

Virginia, 1910, accompanied by a tate of physiological tracings by

Prof, H. W. Emerson.

_ Puarmacy Serres No. 4, sy Joun Ur Lioyp.

History of the Vegetable Drugs of the Pharmacopeia of the United
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~ Committee on Revision, who died May 13, 1901 (see portrait), and

Joseph P. Remington, Ph. M., Philadelphia, Pa. (see portrait), Dr.
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PHarmacy Series No. 5, py Harvey Wickes Fetter.
‘Introduction by John Uri Lloyd. Biographies of John King, M. D.,
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. Mycorocican Serres No. 6,
Synopsis of the Stipitate Polyporoids, by C. G, Lloyd.

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The Biology of North American Caddis Fly Larvae, by John Thomas
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