antity of eggs under a dish cover.

The cover is the female scale bug, and she has laid all those eggs.

Yes, the scales we see on so many plants are the scale bugs.

They are not all alike in shape, or size, or color; here is a different
kind, you see.

[Illustration]

But they are all very prolific; that is to say, they produce a great
many young, and do it in a short time.

Yes, John, the tiny, dark-colored scales that look like little oyster
shells on the skins of oranges are a form of scale bug, and a very
troublesome one, too, to the orange grower.

But though most of these insects are troublesome, the family is redeemed
by a few members that are of great value to us.

One of these is the scale bug that supplies shellac, and all that comes
from it to our markets. These curious bugs give forth a resinous
substance that envelops the eggs and glues them to the twigs whose
juices the bug sucks out. It is this resinous substance that is
collected by breaking off the twigs where the insects are. It is used
for varnishes, as you know, and for polishing wood and other substances.

There are other scale bugs that secrete wax, and some of them produce it
so abundantly, and of such good quality, that it has become an article
of commerce. China wax, which is wax of a very fine quality, is secreted
by a Chinese scale bug, and the wax is used for making fine candles, as
well as for other purposes.

In Mexico we have the cochineal insect, which is a scale bug that lives
on a cactus that grows in Mexico.

Like many others of the scale bugs, the cochineal males have wings and
are not so scalelike as their helpless mates.

But they are of no use to us. It is only the female cochineal we use.

She is raised in great numbers in cactus gardens planted on purpose.

Here is the picture of a cactus with cochineal insects upon it.

[Illustration]

These insects contain a very brilliant, red coloring matter that is used
by us in dyeing leather and wool, and in making paints. The insects are
gathered and dried, and thus sent to market.

Although a few of them are useful to us, the scale bugs, on the whole,
are a serious pest; and they are found on nearly all kinds of plants all
over the world.

You should think all the plants would soon be gone, so many insects eat
them?

Well, they would, only other things eat the insects.

Insects have a great many enemies, after all.

Sometimes the weather is bad for them, the s