The Little Caddice Flies
Here we are in the woods again.
How sweet it smells!
Let us sit down by this brook and look into it.
It is such a clear little stream, with fine sand and little pebbles at the bottom.
What has Nell found that pleases her so?
She says she sees some little bars of sand moving about.
Ned says they are not sand bars but tubes of sand, containing a little live thing.
The truth is, this sand bag is a house, and its occupant is a larva.
The Little Caddice Flies
See the black head come popping out, and the tiny fore legs.
The larva does not come entirely out, you see, but pulls its house along with it, and when it is frightened it pops back into its little stone case.
Mollie says it reminds her of a hermit crab.
A hermit crab, you know, lives on the seashore and takes possession of an empty snail shell for a house.
It comes partly out dragging its house with it, but if you disturb it, it draws back, sometimes quite out of sight.
The Little Caddice Flies
This little larva lives in a house, too, but it is a house of its own making.
It is the larva of the caddice fly, or case fly.
Let us put one of these little sand cases in the saucer here.
Please fill the saucer about half full of water, John. Thank you.
Now, Mollie, I see you have picked up a fine big caddice case.
Put it in the saucer, and let us watch the larva crawl about.
The Little Caddice Flies
It never comes entirely out of the case, you see. It holds on to it with the hinder part of its body.
Its little black head is hard, but its body is soft, and that is why it does not like to expose itself to hungry larvæ that might be living in the water.
May says she wants to see the whole larva.
Suppose we carefully break away the little sand case.
No, indeed, little Nell, we are not going to hurt the larva; we are only going to open its house.
The Airy Water Striders
There, the larva is outside now, and you can see what a tender, pale little thing it is.
It does not like to have its soft body exposed.
See! it is already gathering little bits of sand together.
It seems to be sticking them fast to its body.
It is really binding them together by a saliva-like substance from its mouth.
It draws out little glistening threads that harden into silk as soon as they touch the water.
Queer saliva you think.
But the caddice larva does not find it queer. It is used to saliva that hardens into silk.
Yes, that is the way the larva of the aphis lion and of the ant lion made their cocoons. They spun out silk in this manner.
The caddice larva makes its house of silk and sand and also lines it with a beautiful covering of fine silk.
Yes, May, it papers its walls with silk.
You see it did not hurt the caddice larva to take away its house; it immediately went to work to build another.
Why not pull it out, instead of breaking its house to pieces?
Because if it had been pulled hard enough to come out, it might have been torn to pieces, it is such a tender little thing, and it holds fast so tightly.
So the best way to remove it safely is to break its case bit by bit from around it.
It does no harm to break its case if one is careful. It will soon build another.
Yes, this larva has no distinct thorax. It is like the larvæ of the dobson, the aphis lion, and the ant lion in that respect.
The Little Caddice Flies
See! John has found one whose tube is made of quite large stones as compared with this tube of fine sand that we have broken open.
Some caddice larvæ build houses of wood instead of stone. They stick little twigs together, and some use little pieces of leaves.
Others again use tiny snail shells which, as you can imagine, make very pretty cases.
The Little Caddice Flies
Our little caddice has made a neat little house of fine sand grains very nicely put together.
Some others make much rougher houses.
You will be apt to find the caddice larvæ in any brook and in some ponds, and I hope you will always look for them.
Notice the tracery in the soft mud of the brook.
Those lines that look as though some one had been ornamenting the bottom of the brook are made by our caddice larvæ.
The Little Caddice Flies
They drag their cases along and thus make these lines.
Sometimes such lines are made by the little fresh-water snails; but you can always find the decorator by following along the lines he makes.
What, May? How is the delicate larva able to cling to the case tightly enough to pull it along? If you look at it very carefully, you will find a pair of tiny hooks at the tail end by which it can hold on to the silk lining; and some caddice larvæ have hard points on their backs which help them to hold fast.
The caddice larvæ are carnivorous; that is, they eat animal food.
Yes, May, their food is usually the larvæ of other insects, but you will be glad to know that some of them eat plants too.
They eat the larvæ of the May flies when they can find them and no doubt they build these strong cases about themselves to prevent the May fly larvæ from returning the compliment.
Frank has found some empty cases, yes, and some that are closed at both ends.
Now, let us look at this one closed at both ends. What do you suppose is in it?
The Little Caddice Flies
We will open just one of these closed cases.
There! It is a pupa! Yes, Nell, a very pretty doll is this.
It has a thorax, you see, and an abdomen. Its long antennæ lie close to its body as do its little wing pads.
Yes, the caddice larva grows and moults in the usual way. It keeps adding to its house as it grows longer. Finally, it closes the end of its little tube and lies quite still.
You know what happens next. Its wormlike form divides into thorax and abdomen. Legs and wings appear, attached to the thorax. In short, it is no longer a wormlike creature.
Finally, it comes forth from its case. It never goes into it again.
The Little Caddice Flies
It does not need to, for now it is a dainty little nun, with a long, tan-colored cloak. Its cloak, of course, is its wings folded down about its body. Like the fairy May flies it has no mouth and eats nothing in the adult form.
It looks like a dainty brown moth as it flutters about the bushes and goes flying up and down the brook.
You will always find these little brown-cloaked figures flitting about the brooks, where the caddice larvæ live.
You see the caddice undergoes a complete metamorphosis.
No, it does not belong to the Neuroptera.
Examine its wings very carefully. Look at them through the magnifying glass, and you will see they are clothed with hairs.
So these are the hair wings.
The name of the order to which they belong is Trichoptera, frompteron, a wing, andthrix, a hair.
Sometime you must take a caddice larva from its house and put it in a saucer of water with fine bits of mica, which you know is another name for the isinglass that makes the little windows in our stoves.
If you are fortunate, your caddice will build for itself a little glass house, through whose walls you can look and see what is going on inside.
The Little Caddice Flies
Abdomen(ab-dō'-men). The lower part of an animal's body. The part behind the thorax in insects.
Adult(ă-dult'). (L. adultus = grown up.) Grown to full size and strength.
Anchor(ang'-kor). (Gr. = a hook.) Anchors are used to fasten ships by a line to the bottom of the sea. Applied to anything that holds a movable body fast in one place.
Antenna; pl.Antennae(an-ten'-nee). The feeler in front of the insect's head with which it hears and smells as well as feels.
Aphis(ā'-fis) pl.Aphides(af'-i-dēz).
Aphid(af'-id) The plant louse, of which there are a great many kinds.
Apparatus(ap-a-rā'-tus). Tools or machinery used in working or in making things.
Aquarium(a-kwā'-ri-um). (L. aquarium = watering-place for cattle.) A vessel of water for keeping water plants or water animals.
Attract(at-trakt'). (L. attractus = draw to.) To draw toward.
Audubon(aw'-do-bon), John James. A very famous student of birds and their ways. In his great book, "The Birds of America," which was published in 1827, there are many large colored drawings made by himself.
Beech-nutsSmall, three-cornered nuts that grow on beech trees, and that are very sweet and good.
Breeding-placeThe place where young animals are born.
BroodA family of young animals.
Caddice, orCaddis fly(kad'-is flī). Sometimes called "case fly," from the case or shell which the larva makes about itself; "caddice" is another way of saying "case."
Camera(kam'-e-ra). An instrument for taking photographs.
Cannibal(kan'-ĭ-bal). A human being who eats human flesh. Any animal that eats others of its own kind.
Cargo(kar'-go). The goods or merchandise or whatever is carried in a ship.
Carnivorous(kar-niv'-ō-rus). (L. carnivorus = flesh-eating.) Applied to animals that feed on flesh, and plants that feed on insects.
CastThe cast-off skin of an insect that keeps the form of the insect's body.
Characteristic(kar-ak-te-ris'-tik). Showing the peculiar qualities of a person or thing.
Chitinous(kī'-tin-us). Hard, horny, and shell-like.
Cicada(si-kā'-dä). (L. cicada = tree cricket.) A popular name for insects, like the grasshopper, locust, and cricket, which make a creaking or chirping noise.
Cochineal(koch'-i-nēl or koch-i-nēl'). A crimson dyestuff made of the dried bodies of certain small insects. The insect is also called cochineal.
Cocoon(ko-koon'). (L. concha = a shell.) The silky envelope which the larvæ of many insects spin to cover themselves.
Compact(kom-pakt'). (L. compactus = joined together.) Closely and firmly united.
Compound(kom'-pound). Made up of two or more parts.
Coxa(kok'-sa). (L. coxa = the hip.) The first segment of an insect'sleg, sometimes called the hip.
Crevices(krev'-is-es). (L. crepare = to break, burst, crack.) Narrow openings or cracks.
Descendant(dē-sen'-dant). (L. descendere = to descend.) People or animals who have come from earlier people or animals.
Ear drum(ēr' drum). A membrane stretched across inside the ear.
Ejected(ē-jekt'-ed). (L. ejicere = to throw out.) Thrown out, driven away.
Emaciated(ē-mā'-shi-āt-ed). (L. emaciare = to make lean.) Very thin and wasted.
Emerge(e-merj'). (L. emergere = to rise out.) To appear, to come into sight.
Ephemeridæ(ef-ē-mer'-i-dē). (Gr. word = "lasting but a day.") The name of the May fly order.
Facets(fas'-ets). Little faces; small surfaces.
Femur(fē'-mer). (L. femur = a thigh.) The long bone of the upper leg above the knee. The third segment in the insect's leg.
Formidable(for'-mi-da-bl). (L. formidabilis = causing fear.) Hard to deal with; difficult to overcome.
Fry(frī). The young of fishes; used for any small animals.
Funnel(fun'-el). The shape of a hollow cone.
Gauzy(gaw'-zi). Very fine, thin, and transparent.
Ghosts(gōsts). The spirits or shadows of the dead.
GillsThe breathing organs of any animal that lives in the water.
Gorge(gorj). To feed greedily; to stuff one's self.
Gossamer(gos'-a-mer). A fine filmy substance, like the cobweb of spiders.
GrubThe larva of an insect.
Hearth(hărth). The part of the floor of a room where the fire is built.
Hemiptera(hē-mip'-te-ra). (Gr. = half-wing.) The name of an insect order including many kinds, all known as bugs.
Incomplete(in-kom-plēt'). Not fully finished or developed.
Injurious(in-jew'-ri-us). (L. injuriasus = acting unjustly or wrongly.) Something wrong or harmful.
Inquisitive(in-kwiz'-i-tiv). Curious and prying.
Insatiable(in-sā'-shi-a-bl). (L. insatiabilis = that cannot be satisfied.) Not easily satisfied; very greedy.
Isinglass(ī'-zing-glas). Thin, transparent sheets of mica.
JointThe place where two things or parts of one thing are joined or united.
Keel(kēl). The lowest part of the bottom of a ship.
Kettle drum(ket'-l drum). A musical instrument made of a hollow brass hemisphere over which is stretched parchment. This is sounded by blows from a mallet or stick.
Larva(lar'-va); pl.Larvæ(lar'-vē). The young insect.
LockTo fasten in place.
Locust(lō'-kust). A shorthorned grasshopper.
Mantis(man'-tis); pl.Mantes(man'-tēz). (Gr. = prophet.) An orthopterous insect that holds its arms as if in prayer.
Membrane(mem'-brān). (L. membrana = thin skin.) A thin, soft tissue that connects two parts, or lines a body.
Mercaptan(mer-kap'-tan). (L. mercaptans = taking mercury.) A vile-smelling liquid that gets its name because of its strong action on mercury. It seizes upon mercury, so to speak.
Metallic(me-tal'-ik). Made up of metals, or like metals.
Metamorphosis(met-a-mor'-fō-sis). (L. metamorphosis = change, transformation.) A change of form; a development, as the change of the caterpillar into the chrysalis.
Mica(mī'-ka). A transparent mineral that can be separated into thin sheets or layers.
Microscope(mī'-krō-skōp). An instrument that magnifies, or makes objects look larger when placed beneath it.
Moult(mōlt). (L. mutare = to change.) To shed or cast off the feathers, hair, or skin.
Muscle(mus'-l). Bundles of fibres that have the power of growing longer or shorter. The body is moved by means of the muscles.
Nary(ner'-i). "Ne'er a," a contraction of "never a."
Nerve(nerv). (L. nervus = a fibreortendon.) The nerves are fibres or threads that carry impressions to the brain. Nerved = having fibres, as in the wings of insects.
Neuroptera(nū-rŏp'-te-ra). (Gr. = nerve-wing.) The name of an insect order.
Nymph(nimf). (L. nympha = a bride, a young girl.) The youngof insects that undergo an incomplete metamorphosis.
Ocelli(o-sel'-le), pl. of Ocellus. (L. = a little eye.) The tiny, simple eyes of insects.
Odonata(ō-dō-na'-ta). The name of an insect order to which belong the dragon flies.
OdorsPleasant or unpleasant smells.
Opera-glass(op'-e-ra-glas). Magnifying glasses used at the theatre or opera to make things seem nearer.
Organism(or'-gan-izm). A member of the animal or vegetable kingdom.
Orthoptera(or-thop'-tē-ra). (Gr. = straight-wing.) An insect order to which belong the grasshoppers.
Ovipositor(ō-vĭ-poz'-ĭ-tor). (L. ovum = egg,andponere = to place.) The end of the abdomen of some insects, with which they are able to put their eggs in a good place to be hatched.
Oxygen(ok'-si-jen). A part of the air that is necessary to all animal and vegetable life.
Parasites(par'-a-sītz). Animals or plants that live on others.
Phylloxera(fil-ok-sē'-ra). (Gr. = leafanddry.) An insect very destructive to grape vines.
Plaited(plāt'-ed). Folded length-wise like the plaits of a closed fan.
Plecoptera(plē-kŏp'-tē-ra). (Gr. = twistandwing.) An insect to which belong the stone flies.
Pollute(pō-lūt'). (L. polluere = to make unclean, to soil.) To make foul or unclean.
Pores(porz). (L. porus = a way, a passage.) Small openings in the skin to help in breathing.
Prey(prā). (L. præda = property taken in war.) An animal in the chase; game.
Prolific (prō-lif'-ik). Fruitful; producing young in abundance.
Propel(prō-pel'). (L. propellere = to drive, or push forward.) To urge onward by force.
Prophet (prof'-et). One who tells of the future.
Pulvillus(pul-vil'-us); pl.Pulvilli.(L. = a little cushion.) A little pad or cushion on an insect's foot.
Ravenous(rav'-n-us). Greedy, furiously hungry.
Repel(re-pel'). (L. repellere = to drive back.) To drive back, to check.
Resinous(rez'-i-nus). Like resin, which is made from pine pitch.
Rudimentary(rew-di-men'-ta-ri). (L. rudimentum = a first attempt.) Imperfectly developed or in an early stage of development.
Saliva(sa-lī'-va). Spittle. The liquid formed in the mouth, which mixes with food, and helps it to digest.
Segment(seg'-ment). (L. secare = to cut.) A part cut off, a section.
Seize(sēz). To grasp, to clutch.
Sensitive(sen'-si-tiv). Quick to feel. The nerve of the eye issensitive to light, quick to feel light.
Shellac(she-lak' or shel-ak'). It is made from a coloring matter in the bodies of certain insects. A polish which is used with varnish.
Silk(sīlk). A fine, soft, strong thread made by the larvæ of certain insects.
Skeleton(skel'-e-ton). (Gr. =driedup.) The dry bones of the body taken together.
Socket(sok'-et). Any hollow thing or place which receives or holds something else.
Soothsayer(söth'-sā-er). One who pretends to know what the future holds for us.
Source(sōrs). The place where anything begins.
Species(spē'-shez). A group of closely related animals or plants.
Spine(spīn). (L. spina = a thorn). Anything sharp and slender like a thorn.
Spiracle(spir'-or spīr-a-kl). (L. spiraculum = a breathing hole). An air-hole.
Survivals(ser-vī'-valz). (L. supervivo = to live over.) Those outliving the larger number.
Swammerdam, Johannes. A Dutch entomologist, born in Amsterdam in 1637. He published several books on the natural history of insects.
Syringe(sir'-inj). (Gr. = a pipeorreed.) A little instrument for drawing in water, and forcing it out again.
Tarsus (tar'-sus); pl.Tarsi. (Gr. = the sole of the foot.) The little segments that make up the insect's foot. Also the little bones of the instep.
Telescope(tel'-e-skōp). (Gr. = to view afar off.) An instrument by which distant objects are made to appear nearer and larger.
Thorax(thō'-rax). (Gr. = armor for the breast.) That part of the body of animals between the head and the abdomen.
Thysanura(this-a-nū'-ra). (Gr. = tassel and tail.) An insect order to which belong the scale fishes.
Tibia(tib'-i-a). (L. tibia = a slender pipe, a musical instrument.) A long, slender bone in the leg, below the knee. The fourth segment in an insect's leg, generally long and slender.
Transformation(trans-for-ma'-shon). (L. transformare = to change the shape of.) A change in form or nature.
Transparent(trans-par'-ent). (L. trans-parere = to appear through.) Easily seen through.
Transportation(trans-por-ta'-shon). (L. trans-portare = to carry over.) Carrying from one place to another.
Tremendous(tre-men'-dus). (L. tremendus = fearful,fromtremere, to tremble.) Very wonderful, astounding.
Trichoptera(trī-kop'-te-ra). (Gr. = hairy-wing.) An insect order to which belong the caddis flies.
Trochanter(tro-kan'-ter). (Gr. = the ball on which the hip bone turns in its socket.) The second segment of an insect's leg.
Unlock(un-lok'). To unfasten something that has been closed.
Unsubstantial(un-sub-stan'-shal). Not real or solid, without substance.
Vacated(vā'-kat-ed). (L. vacare = to be empty or vacant.) Emptied; possession given up.
Vegetation(vej-e-tā'-shon). (L. vegetare = to quicken.) Living plants.
Veined(vānd). (L. vena = a vein.) Marked as with veins, streaked.
Vibrate(vī'-brāt). (L. vibratus = set in motion.) To swing; move to and fro.
Vibration(vī-brā'-shon). Motions back and forth. Vibrations may be too small for us to see.
Victimized (vik'-tim-īzd). Made a victim of, deceived, badly treated.
Voracious(vō-rā'-shus). (L. vorax = devouring greedily.) Eating food in large quantities.