THE HOP-MOTH
“What is that pretty butterfly in your box, next to the pyralis?” Emile
asked his uncle when the latter was showing the children some of his
specimens of moths and butterflies. “It has silver wings bordered with
red.”
“That is not a butterfly, my boy,” replied Uncle Paul; “it is a moth
that infests hop-vines.”
“Are hops those things they make beer with?”
“Beer is not made from hops, my boy; it is made from barley. First the
barley is slightly moistened, after which it is kept at a mild
temperature. The grain begins to sprout just as it would do if sown in
the field. For the nourishment of the little plants, which have no
roots as yet, a special food already prepared is needed, just as the
young kitten, not yet big enough to catch mice, needs its mother’s
milk. All grain, in beginning to grow, whether it be wheat or oats or
rye or any other, requires a special form of nourishment, ready
prepared. But where do you suppose it is to be found? You hadn’t
thought of that. I will tell you. The grain has it in itself. In a
kernel of barley or wheat or oats or rye there is a white substance
which, when ground to powder, is known as flour.”
“Then the sprouting plant feeds on flour?”
“Not exactly; flour is too coarse a food for it. The little plant takes
its nourishment much as we do when we are very small. It sucks up water
holding in solution the substances needed for its growth. But flour
will not dissolve in water, as you very well know; consequently, the
little plant would die of hunger right beside its store of provision if
the flour were not prepared for it—I might say, cooked for it—in a way
suited to its needs.”
“That must be a funny arrangement—food cooked for a plant!”
“It is more wonderful than you can imagine. As the sprout pushes upward
the flour in the grain is being turned to sugar, real sugar, very sweet
and easily dissolved in water; so that the young plant has for its
nourishment a sufficient supply of sweetened water or, to express it in
another way, a sort of milk.”
“Oh, yes!” cried Emile. “Now I understand. Last Christmas Mother
Ambroisine put some wheat to sprout in a plate and kept it moist on the
mantelpiece. When the little blades began to show, the wheat was all
soft and would crush under your fingers; and it gave out a sort of very
sweet milk.”
“This wonderful transformation of flour into sugar during germination
is turned to account by man in making beer. He causes barley to
germinate, and when he judges that all the flour substance it contains
has turned to sugar he quickly kills the little plants, as otherwise
the sweetened liquid would be taken up by them and would undergo
another transformation by being turned into plant substance.
Accordingly, the grain is promptly dried in an oven, after which it is
ground in a mill, and this ground barley is called malt. By adding
water and keeping it at a mild temperature we induce a fresh change:
the sugar turns to alcohol, which is the essential element of beer and
wine.”
“The flour of the grain, then,” said Jules, “turns to sugar or to plant
substance or to alcohol, according to the way it is treated; is that
it?”
“Yes, and it can be converted into many other things. Boiled with water
it becomes paste. After entering into the composition of beer it can be
turned into vinegar by being left exposed to the air and allowed to
sour. But we will not now dwell on these various changes. Let us return
to the subject of beer. In order to impart to that beverage the bitter
taste and the aroma peculiar to it, we use hops. Barley is the
fundamental ingredient of the drink, hops are the flavoring.
“The hop-plant is a long, slender vine unable to hold itself up without
supporting poles, around which it twines to the height of perhaps ten
meters. Its leaves are lobed somewhat like those of the grape, and its
fruit takes the shape of cones or catkins similar to those of the
pine-tree, but much smaller and composed of thin scales coated with a
sort of bitter resin. It is these cones that are used in making beer.
Hops are extensively cultivated in Alsace and in Germany. The chief
enemies of the hop-vine are two worms, one of which nibbles the roots
and the other the inside of the stem or vine.
“The epialidæ are distinguished from all other moths by their very
short antennæ. Their larvæ live in the ground and feed on roots. The
most important member of this family is the hop-moth, of which the male
has white wings touched with silver and edged with a reddish border,
and the female has fore wings of bright yellow with tawny edges and two
tawny oblique stripes. The grub is whitish, covered with little yellow
tubercles overgrown with black hair. It does great damage to hop
plantations by gnawing the roots. To destroy it the hop-grower is
advised to spray the base of the vine with water in which hog-manure
has been left to steep—an application that is said to kill the worms.
“Within the stem of the plant lives the grub of the pyralis that I show
you here. The moth has dark-yellow fore wings edged with a scalloped
stripe of a lighter shade and marked with a number of red spots. The
hind wings are white with purple spots and yellowish edges.”
“Alongside of that moth there are two more in your box,” Emile pointed
out.
“They are the madder-moth and the woad-moth. Madder used to be
cultivated for its root, which yields a red dye, the most beautiful and
lasting of all red dyes.”
“Isn’t Mother Ambroisine’s Sunday kerchief dyed with madder?”
“Yes; and with the red there are black, pink, garnet, and violet on the
kerchief, all obtained from madder. In the methods formerly in use
various drugs were first applied to the goods to be dyed, this being
done by means of wooden blocks engraved with the desired patterns,
after which a bath of boiling water containing powdered madder root
brought out all the different colors, at once, their respective tints
depending on the drugs previously applied. These colors, of which there
were many varieties, had the great advantage of never fading in the sun
and of resisting soap; hence madder used to be the most highly prized
of dyestuffs and was a source of much profit to Alsace and the
department of Vaucluse, the only districts devoted to its culture. Its
insect foe was the moth I now show you. At weeding-time it was the
custom to destroy the caterpillars, which fed on the leaves of the
plant.
“Woad is another plant used in dyeing. Prepared in a certain way, the
green matter of its leaves gives a fine blue color. The caterpillar of
a leaf-rolling moth eats first the woad leaves and then the stalk.”