Why, little Nell! What is the matter?

You do wish the frogs would stop spitting on the gra.s.s?

Let me see; why, poor child, she is all covered with frog spittle.

That is kind, Ned. See, he is wiping her ap.r.o.n off with some fresh, clean leaves. Let us rest awhile under this shady tree.

John, pick that gra.s.s blade with the frog spittle on it. Be careful not to disturb it.

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There is a surprise in store for you; this white frothy substance that is so abundant in some places in the summer and that looks like spittle is--guess what?

Frog spittle, May says. So you think the frogs spit on the gra.s.s do you?

They must be tall frogs to reach up so high.

With this little twig let us carefully brush away the white froth.

Now see.

Yes, there is something in the centre of it.

It is the larva of a--bug!

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The female bug, and here is one of the little things, lays the egg on the leaf or twigs, and when it hatches the young bug sucks out the sap of the plant which finally appears as this white froth.

The larva remains surrounded by the froth until its transformations are complete.

Just before the last moult it stops sucking out sap. The froth dries about it in the form of a little room, and in this it undergoes its last moult and comes out--an adult bug.

The froth is supposed to be used as a protection, and it may be against some enemies, but there are certain wasps that delight in invading the frothy ma.s.ses and hauling out the unwilling morsels within to feed to their young.

No, little Nell, the frogs have nothing whatever to do with this frothy substance which was called frog spittle before people understood about the little insect that made it.

They really thought the frogs did it.

The adult spittle insect is called a frog hopper, and it has the power of leaping very well.

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PRETTY LEAF HOPPERS

Just see this bush! Be careful not to shake it.

It is covered with such pretty, bright-colored little insects.

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There, May ran against the bush and see--they are hopping wildly off in every direction.

Yes, little Nell, they do sound like rain drops pattering on the leaves.

They are prettier than the spittle insects and more slender, but they hop about in very much the same way.

The larvae do not make froth, however.

These are the leaf hoppers.

What big heads they have!

And how daintily their green forms are pencilled with red lines.

There are a great many species of the leaf hoppers, and not all of them are as pretty as these.

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Some of them are very small indeed, and some do great damage to the grain crops and the fruits.

They suck out the juices of the plants.

If you sweep the insect net over bushes or through the gra.s.s in midsummer, you will be pretty sure to draw in a good collection of leaf hoppers.

Most of us are only too well acquainted with the rose-leaf hopper that swarms on rose bushes and kills the leaves. If we have not noticed the insect itself, we have not failed to notice the little white skins that it has cast off and left clinging to the leaves.

Yes, these are the little skins it discards when it moults.

John says we can kill them by washing the bushes with strong soap suds.

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Ned says it is better yet to spray them.

It is better and also easier to spray them than to wash them.

You know there are machines for spraying trees and other plants. They consist of a tank to hold the liquid that is to be sprayed and a pump to force it through a rubber pipe with a sprinkler at the end.

Very often a mixture of soap and kerosene oil, known as "kerosene emulsion," is used to spray with.

Paris green and blue vitriol, both very poisonous, are often used on grape vines before the grapes are formed, and very gaudy vines they are for a little while after this bright poison has been sprayed upon them.

Although insects are so very interesting, we have to protect ourselves against many species in order to live.

Yes, John, it is oftentimes merely a question which shall profit by the crops we plant, the insects or ourselves.