The Potter journal. [volume] (Coudersport, Pa.) 1857-1872, 1858-07-29


of sickly green color. This process,
Mr. Henderson informs US, takes place
uuiforMly, but most rapidly when the
plant is freely watered and exposed to sun
AMI air, as the specimen exposed vas not
TO all external appearance, the dlsel>e
was identical with the ordinary potato r, t
as it attacks the vines. Some pieces IF
early (this years. potatoes, placed in the
jar were also plainly attacked BY the rot
during the four days ofexposure.
Ma. Henderson states that he has been
engaged in this research since 1915 that
in 1889 lie discovered the bug on the
vines, but thought it was confined t.
them. During the last year he has found
it Oh the tubers, and watched its effects
upon them. 1t appears on the vines in
from two and half to three months after
planting, according to soil and manure, a
richly msnured soil producing the perfect
insect sooner.
The natural history of the insect begins
with the development of the egg. This
is invisible to the naked eve, but can be
seen with the aid of lens, agglutinated to
the skin Of the potato 1t is of an oblong
form and is planted with the seed potato.
The egg may be Matched in a warm, moist
place The entire period of development
is not settled. Mr.. II. exposed plant to
the insect, under proper precautions, and
from the time Of TIE exposure to the time
the young insect OF the next generation
obtained his wings was three months
The process of reproduction has been in
geniou5Iy watched by Mr.. Henderson
The egg planted with the seed potato is
hatchcd, and the young insect stays in the
ground until he gets wings. In the mean
time he is engaged in singing the tubers,
each perforation poisoning the root aud
hegcttiug the rot. While yet in the
ground, and as early as the tenth day of
existence, the young insects cohabit, and
from the great rapidity with which they
propagate, Mr.. II argues that the egg is
deposited before the first emergence from
the ground although in case of cold, wet
weather. the insect sometimes leaves the
vines and returns to the tuber Only a
few days are required for the entire des-
truction of the vine. The insect is re-
markably industrious, but the destruction
of the vines does not affect the tuber ex-
cept to stop its growth.
Mr.. Henderson finds ready expIana-
ton for the greater healthfuiness of the
potato in sandy soil He finds that the
grains Of sand greatly annoy and cripple
the insect, and as the light soil is heaved
up by the growth of the root, the sand
imparts or falls down, preventing the ac-
cess of the fly. In stiff soil the insect
readily leaves the ground through the
cracks opened by the growth CT the tuber,
and having stung it, comes to the surface
and attacks the vine, especially after heavy
showers Daring the past Winter Mr..
Henderson has had thousands of the young
insects hatched under glass, and to try
their power of mischief, has experimental
with bugs only quarter grown. The
plants exposed showed unmistabakle signs
Of disease on the fourth day.
These statements we regard as impor-
tant. So much is evident. Mr.. Hendcr
son, by means Of this insect, produces po-
tato rot at will. When healthy plant is
shown US, the insect applied, and the rot
follows in four days with unerring certain
ty, there is good reason to suppose that
the problem has been solved.
As to cure, Mr. Henderson thinks there
is no serious difficulty. If we put stop
to the planting of the egg with the seed
potato, we stop the propagation Of the IN
sect. The egg being invisible, any means
applied should be thorough, and reach
the whole surface of the root. Mr.. Hen.
derson states that by spIinkling quick,
lime over the potato as it is cut for plant
ing, the moisture will dissolve the lime
aud bathc the tubers in a caustic alkal
which will destroy the egg At this time
Of the year the ravages Of the insect may
be prevented by packing the earth arount
the tuber firmly with the foot, which will
smother the insect. We may add that il
is probably the same insect which has re
Gently attacked the grape-vines.
Since writing the above, we have founC
one of the insects in our jar, which hae
deserted the now rotten vines, at work un
! dergrOund upon 4 sound young potato.