Martinsburg herald. [volume] (Martinsburg, W. Va.) 1881-1920, 1917-07-28

The eggs hatch in about eight days
into young females again, like the
parent, and migrate to all parts OF 4
the vine to form new gals. Six or
seven generations Of these winglcss {
females follow one another through T
out the summer frequently leaving I
the leaves completely studded with
the 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 sub I
terraneln generations of wingless fe-
males is developed The root form T
differs slightly from the inhabitant of
the leaf gals. and the swellings or
eXcreseences on the roots are analog~
Gus to those on the leaves During
the late summer and fall of the sec
ond 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 neighboring I
vines. These winged lice lay their
eggs within day or two in groups T
OF two OF four in cracks in the bark
or beneath loose bark on the old
wood of the vine and die soon after. !
The eggs are Of two sizes, the small
er and fewer in number yielding
males in nine or ten days. and the
larger the females of the only sexed
genergtion developed in the whole
life round of the insect. In this last
and sexed stage the mouth-parts OF
both are documentary and no food at
all is taken, The insect is very min |
ute and resembles the newly Matched
louise of either the gall or the root
form. The single egg of the larve
lyike female after fertilization rap
idly increased i'll size until it fills
the entire body of the mother and
Is laid within three or four days, |
bringing us back to the winter egg
or starting point.
= Ills INO-gt dl AAAG lOuhu rs AIt
necessary to the existence Of the
species, and the root form may and
usually does go on in successive
broods year after year, as in the case
with European vines, on the leaves
OF which gals rarely occur. Under
exceptional circumstances all of the /
different stages may be passed
through in single year The young
from leaf-galls may also be easily
colonized on the roots, and 1t is prob !
able that the passage of the young
from the leaves to the roots may
take place at any time during the
summer. The reverse Of this process,
or the migration OF the young di-
rectly from the roots OF the leaves,
has never been observed
The complicated details noted above
were only obtained after years OF
painstaking research conducted by !
the late Professor Riley in this c0un-
try and many careful Investigators
in France
MEANS OF DISPERSION.
The distribution Of phylloxera, is,
first by means of the winged females
second, by the escape usually in late
summer, of the young root licel
through cracks in the soil and their
migration to neighboring plants
third, by the carrying Of the young
leaf-gall lice by winds or other agen-
cies, such as birds or insects to dis
tant plants; fourth, by the shipping Of
infested rooted plants or cuttings with
winter eggs. BY the last means the
phylloxera has gained a worldwide
distribution; the others account fer
local increases.
REMEDIES AND PREvENTIvES. J
The enormous loss occasioned byI
this insect when it reached the wine
districts of the Old World led to the
most strenuous effort S to discover
methods OF control. OF the hundreds
of measures devised few have been
at all satisfactory in results. The
more important ones are the use Of
bisulphide Of carbon and submersion
to destroy the root lice; and, as pre-
ventiye measures, the use Of resistant
American stocks on which to graft
varieties subject to phyIloxera lRd
the planting Of vineyards in soil OF
almost pure sand
SULPHEDE or CARBON - The (
use OF this liquid insecticide is prac-
ticable only in soils Of such consist
ency as to hold the vapor until it
acts on the root lice and yet friaDle
enough TO afford it enough penerta-
ton. 1t viii not answer in compact
clay soils, in very light sandy ones
or in soils liable to crack excessiDly. f
The liquid is commonly introduced
into the soil BY hand iuieetOps at any