The Insect Folk Part 43

Some caddice larvae build houses of wood instead of stone. They stick little twigs together, and some use little pieces of leaves.

Others again use tiny snail sh.e.l.ls which, as you can imagine, make very pretty cases.

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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 larvae 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 larvae.

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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 larvae have hard points on their backs which help them to hold fast.

The caddice larvae are carnivorous; that is, they eat animal food.

Yes, May, their food is usually the larvae of other insects, but you will be glad to know that some of them eat plants too.

They eat the larvae of the May flies when they can find them and no doubt they build these strong cases about themselves to prevent the May fly larvae 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?

We will open just one of these closed cases.

There! It is a pupa! Yes, Nell, a very pretty doll is this.

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It has a thorax, you see, and an abdomen. Its long antennae 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.

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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 larvae 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 gla.s.s, 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, from _pteron_, a wing, and _thrix_, 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 isingla.s.s that makes the little windows in our stoves.

If you are fortunate, your caddice will build for itself a little gla.s.s house, through whose walls you can look and see what is going on inside.

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+-----------------------------------------------------------------------+ |Transcribers note: In this text letters with a macron or breve are | |represented thus: | | | | | |"a" with a macron [=a] "a" with a breve [)a] | |"e" with a macron [=e] "e" with a breve [)e] | | | |"i" with a macron [=i] "i" with a breve [)i] | |"o" with a macron [=o] "o" with a breve [)o] | +-----------------------------------------------------------------------+

GLOSSARY

~Abdomen~ (ab-d[=o]'-men). The lower part of an animal's body. The part behind the thorax in insects.

~Adult~ ([)a]-dult'). (L. adultus = grown up.) Grown to full size and strength.

~Anchor~ (ang'-kor). (Gr. = a hook.) Anchors are used to fasten s.h.i.+ps 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~ ([=a]'-fis) pl. ~Aphides~ (af'-i-d[=e]z).

~Aphid~ (af'-id) The plant louse, of which there are a great many kinds.

~Apparatus~ (ap-a-r[=a]'-tus). Tools or machinery used in working or in making things.

~Aquarium~ (a-kw[=a]'-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.