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 larvae of the
dobson, the aphis lion, and the ant lion in that respect.
[Illustration]
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 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 shells which, as you can imagine, make very
pretty cases.
[Illustration]
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.
[Illustration]
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.
[Illustration]
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
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