Belding banner. (Belding, Mich.) 1889-1918, 1912-10-03

tack horticultural crops. These
minute creatures, only one one
hundred-and-f iftieth of an inch in
length, are invisible to the I'M
aided eye, and as seen under a
good hand lens appear as the mer-
est speck. Although the mites
themselves are probably unfamil-
lar to most orchardists. their work
is well known, to pear growers
and apple growers, in the reddish
or greenish pimples or blisterlike
spots to be noted in early spring
on the young foliage OF these
plants. Later these blisters be-
come brown and dead. spotting
and blotching the leaves, the in
Jury resembling that due to leaf
spot fungi or from sprays, with
which injury, in fact, the work
of this mite is frequently confus-
ed. When the creatures are abund-
ant the foliage may be almost
covered with the blisters or brown
spots, and the usefulness OF the
leaves to the tree is thus greatly
impaired. Foliage severely injured
will fall prematurely, retarding
the development of the fruit and
in extreme cases much OF the crop
will fall to the ground.
The leaf blister mite is not an
insect, but belongs to that class
of animals containing the spiders,
!. scorpions, daddylonglegs, ETC., ana
the order Acarina, represented
by such well-known forms as the
scab mite of sheep, the cattle tick,
and the red spider. It's family,
the Eriophyidae (Phytopidae), con-
tains numerous species, all OF
which are plant feeders, attacking
principally the buds and leaves.
Several members of the family are
of much economic. Importance.
Eriophyes padi Nalepa is the
cause of the nail-like gals some
times found on leaves of the plum.
Phyllocoptes cornutus Banks feeds
upon the upper surface OF the
leaves of the peach, so injurlng
them as to give the foliage sill
very sheen.
Origin and Distribution
The mite is not native to the
United States and was probably
introduced at an early period, pre-
sumably from Europe on nursery
stock, buds, or scions. 1t was re-
corded in the United States by
Townend Glover, in 1872, and since
that date has made its appearance
in the principal pear and apple
growing regions of the United
States and Canada. 1t is known
to occur in portions of the old
world being at the present time
truly cosmopolitan pest.
Character OF Injury and Destructiyeness
The mites pass the winter on the
trees, under the bud scales, and
attack the leaves as soon as these
begin to push out in the spring.
They bore small holes from the
underside to the interior of the
leaf, where they deposit Their
eggs, and with their progeny feed
upon the tender cells of the leaf
substance. Their activities within
the leaf tissues very quickly re-
suit in the development of gals
or swellings. These are at first
small, pimple-like eruptions, es-
pecially evident on the upper sur
face of young leaves, whitish in
color on the apple, but usually
with a reddish tinge on the pear.
The spots soon increase in size,
the largest becoming as much as
one-eight of an inch in diameter.
On pear leaves the spots, as rule,
become red, often brilliantly col
ored as they grow, whereas on APP
pie this reddish. coloring is absent
! Or faint. On the underside of the
leaf the gals are whitish and
blistering not differing much from
the general color of the leaf sur
face. Later they turn brownish or
black, due to the death of the in
iured leaf cells, lose much of their
thickness, and some may become
somewhat shrunken.
On pear, the gals occur more
along each side of the midrib of
the leaf and on apple at the base
of, and along the margins Of the
leaf. When numerous, however
the spots will merge together
forming large patches or bands OF
variable size, often involving most
OF the leaf. When thus abundant
the leaves may become more OF
less ruptured and wrinkled, and
in the case of the apple the mar
gins may curl up, showing the
underaide Leaves badly infest-