In No. 4, page 62, of the _Horticulturist_, a correspondent complains of
the ravages of the Grape Vine Flea Beetle. This insect has been
unusually abundant in many localities this season, and where abundant is
always very destructive to the grape vines. Its common name suggests
activity, and it is as active in mischief as in movement, hopping during
the heat of the day from leaf to leaf and from branch to branch with a
speed almost equal to that of its smaller namesake.
[Illustration: FIG. 9.]
The Beetle, Fig. 9, survives the winter in the perfect state, lying
dormant and torpid under leaves, pieces of bark, or other suitable
shelter until called into activity by the reviving warmth of spring. It
is a pretty little beetle of a polished steel-blue or green color,
sometimes shading into purplish, with a transverse depression across the
hinder part of the thorax. The under side is dark green, the antennæ and
feet brownish black. Its length is about three-twentieths of an inch,
and it has stout robust thighs, by means of which it is able to jump
about very briskly. It is more destructive in spring than at any other
time, for then before the buds have burst it is astir, with appetite the
keener for its long winter fast; and while the tender growth is
swelling, this little mischief-maker pounces on it and eats it out to
its centre, thus consuming in a short time two or three embryo bunches
of grapes.
[Illustration: Fig. 10.]
The beetles appear on the vines in the latter part of April and continue
to be destructive until late in May, after which they gradually
disappear. Before leaving, however, they deposit clusters of orange
colored eggs on the under side of the young vine-leaves which hatch in a
few days into small dark-brown worms, which feed on the upper side of
the leaves, eating numberless holes in the softer parts, in the manner
shown in Fig. 10. In about three or four weeks they become full grown,
when they present the appearance shown at _b_, in the Fig.; but here is
a magnified view; the hair-line at the side shows the correct size. They
are then about three-tenths of an inch long, usually of a light brown
color above, sometimes yellowish, at other times of a darker shade,
paler on the under surface. The head is black, and there are six or
eight shining black dots on each of the other segments of the body, each
emitting a single brownish hair. The feet, six in number, are black, and
there is a fleshy orange colored proleg on the terminal segment. When
progressing, the larvæ does not move its body regularly, but raises it
suddenly behind.
In the early part of June they leave the vines and descend to the
ground, where they burrow in the earth, and forming a little smooth oval
cell, change to dark yellowish chrysalids, as shown at _c_, Fig. 10.
After remaining about two or three weeks in this state, the perfect
beetles issue from them, and the work of destruction still goes on; but
as they live altogether on leaves during the fall, of which there is
usually an abundance, the injury they do at that season is scarcely
noticed.
To destroy the beetle it is recommended to strew in the fall,
air-slacked lime, or a good quantity of unleached ashes around the vines
infested. The larvæ may be destroyed by the use of hellebore and water,
or where it can be safely used, a mixture of paris-green and water, in
the proportion of one or two teaspoonfuls to a pail of water. This
latter mixture would also doubtless kill the beetles if the vines were
well syringed with it in spring. During the chilly mornings of early
spring the beetles are comparatively sluggish and inactive, and some
chance is then afforded of hand-picking and destroying them. Fowls
allowed at this time the run of the vineyard are also said to devour
large numbers of them.
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