Sequachee Valley news. (Sequachee [Sequatchie], Tenn.) 1896-1952, 1896-10-15
GRAPE ENEMIES.
The PhyllOxera. History
and Habits.

The phylloxera was carried to
France about 1859, on rooted Amer
ican wines, and has since spread
through the principal vine districts
of southern Europe, extending also
intoj algeria and and through south
ern Russia into the adjoining coun-
tries of Asia. 1t has also been carried
to3New Zealand and south Africa
In this country 1t was at first known
only in the region east of the Rocky
Mountains, but was after found In
California, where, however, it is con-
fined practically to the vine districts
of the Napa and Sonoma valleys.
The lite cycle Of the phylloxera
is a complicated one 1t occurs IN
four forms In the following order;
The leaf-gall form (gallicola), the
root or destructive form (radicicola),
the winged or colonizng form, and
tie sexual form. The leaf gall insect
produces from 500 to 500 eggs for
each individual, the root-inhaOiting
insect not much above 100 eggs, the
winged insect from 5 to 8, and the
last or sexed insect but l egg. This
last is the winter and may be taken
as starting point of the life cycle.
l is laid in the fall on old wood,
and matches, the spring following,
into louise, which goes at once to a
young leaf, in the upper surface of
which it plants its beak. The suck
ing and irritation soon cause a de-
preston to form about the young
louise, which grows into gall pro-
jecting on the lower side of the leaf.
In about fifteen days the louise be-
comes plump, orange yellow, full
grown, wingless female, and fills its
gall with small yellow eggs, dying
soon after. The eggs hatch IN about
eight days into young females again,
like the parent, and migrate to all
parts of the vine to form new gals.
Six or seven generations of these
wingless females follow one another
Throughout the summer, frequently
completely studding the leaves with
gals. With the approach of cold
weather the young pass down the
vines to the roots, where they re-
main dormant until spring. The
root is then attacked and series of
subterrean generations of wingless
females is developed. The root
form differs but slightly firm the in
habitant of the leaf gals, and the
swellings or excrescences on the
rK are analogous to those on the
leaves.
During late summer ard fall of
the second year some of the root lice
give rise to winged females which
escape through cracks in the soil on
warm bright days and fly to neigh
boring vines These winged lice lay
their eggs within a day or two in
groups of two or four in cracks in the
bark or beneath lose bark on the old
of the vine and die soon after. The
The eggs are of two sizes, the small
er or fewer in number yielding males
in nine or ten days, and the larger
the females of the only sexed gener-
ton developed in the whole life
round of the insect. In this last and
sexed stage the mouth parts of both
sexes are rudimentary, and no food
at all is taken. The insect is very
minute and resembles the newly
Matched louse Of either the gall or
the root form. Tie single egg of
the larva-like female otter fertilIza-
ton rapidly increase in size until it
fills the entire body of the mother
and is laid within three or four days,