The Insect Folk Part 32

Yes, bed bugs are parasites too.

Besides the lice that live on human beings, there are species that infest animals.

BIRD LICE AND BOOK LICE

Bird lice are not lice!

That is, they do not belong to the bug order.

They belong to a small order by themselves, but they are parasites like the lice.

The little white book lice that scurry away when we open an old book that has been standing on the back shelf, are not lice, either; they also belong to a little order of their own, and are constructed very differently from the true lice.

FRIEND CICADA

WHIR-R-R-R-RRRRR!!

May says she wishes that locust would keep quiet. It makes her warmer than ever to hear him carrying on so this hot day.

John says it is the weather that is warm, not the song of the locust.

And yet, locusts generally sing during the hottest part of the summer, so that we have learned to a.s.sociate them with warm weather.

Since we must listen to its shrill out-cry, I wish we could also see it.

Ah, that is a wish soon gratified! Here comes one out of John's pocket.

[Ill.u.s.tration]

John says it is _not_ a locust.

Ah, yes, the shorthorned gra.s.shoppers are the real locusts, and this fellow has somehow got the name.

But it is not a locust.

It is also called the dog-day harvest fly, but it is not a fly, though it looks considerably like one.

Really, you know, it is a--bug!

Yes, it belongs to the bug order.

Its true name is cicada, and its shrill midsummer song has been famous from the beginning of time.

[Ill.u.s.tration]

It looks like an enormous fly, but its mouth parts are the mouth parts of the bug, and in other respects it resembles the members of the bug order, when it is examined closely.

What gla.s.sy wings!

Let us spread them out carefully. Four of them it has.

The cicada, you see, has no wing covers. Nor are its upper wings, half wing cover, and half wing, like those of so many of the bugs.

No, all four of its wings are alike, and all four are flying wings.

When it is at rest, the inner wings slip out of sight under the outer ones, which fold down like a roof over its body.

See how beautifully the wings, are veined.

You think cicada has a very broad back, Nell?

So it has, and a broad head.

[Ill.u.s.tration]

See its black eyes on the corners of its head!

How many facets have its eyes?

I wish I knew, but I do not. This, however, I can tell you. If you look on the top of its head between its compound eyes, with a magnifying gla.s.s, you will find it has three little eyes there.

These small eyes are simple, and are called _ocelli_.

Many insects have ocelli, indeed, some of the gra.s.shoppers have these extra eyes on top of their head.

May says the gra.s.shoppers are very astonis.h.i.+ng insects.

You think you know all about them, and you are all the time finding out something new. You would not be apt to notice these little ocelli on the gra.s.shopper's head, they are so small, and besides, some of the gra.s.shoppers do not have them.

Yes, Mollie, it is the same with the crickets and katydids. Some species have ocelli, and some have not.

If you look full in the face of a cicada, you can see the three little round ocelli between the compound eyes.

[Ill.u.s.tration]

They show very plainly with a magnifying gla.s.s.

Indeed, it is difficult to explain what the ocelli are for.

Some think they are to see objects close at hand, while the compound eyes see more distant objects.