Worcester daily spy. [volume] (Worcester [Mass.]) 1850-1888, 1858-08-06
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The PoTAro RoT-Hs Cause and caye.-
Mr.. Henderson's Discoveries. the morn.
ing of the oath of June, Mr.. Alexander Hen.
derson Of Buffalo, left at our Office, saws the
New York Buffalo Commercial, a glass Jar.
containing sound and healthy potato plant,
covered in by perforated paper so as to af-
ford air. He had placed it there at seven
o'clock, A. M, and with it were confined
some six or eight insects, which Mr.. Il. be-
lieyes to be the source of the potato rot. The
insect itself we cannot describe scientifically,
I'll about half the size of the common house,
ny, OF orownlsh color, has six legs, two pairs
OF light dlaphanous wings, two antenna, and
q long, strong proboscis Mr.. H. thinks it is
the Phytocoris, but is not positive as to that.
AT the end of twenty -four hours, the plant
was evidently diseased. The insect was ae-
lively engaged upon its various portions.
which became brown and mouldy in the leaf.
while the stalks, in the course of two or three
days, suffered putrescent change, until. on
the otp' some OF them fell over by their own
weight, the stalk being swollen and soften.
ed, in some places quite to jelly of a sickly
green color. This process, Mr.. Henderson
informs us, takes place uniformly, but most
rapidly when the plaut is freely watered and
exposed to sun and air, as the specimen ex-
posed was not. To all external appearance,
the disease was identical with the ordinary
potato rot as it attacks the vines. Some
pieces of early (this years. potatoes, placed
IN the jar were also plainly attacked BY the
rot during the four days of exposure.
Mr.. Henderson states that he has been en-
gagged in this research since 1916; that in
1890 he discovered the bug on the vines, but
thought 1t was confined to them. During the
last year he has found it on the tubers, and
watched its effects upon them. 1t appears on
the vines In from two and a halt to three
months after planting, according to soil and
manure, richly MANFRED soil producing the
perfect insect sooner.
The natural history of the insect begins
with the development of the egg. This is in
visible to the naked eye, but can be seen with
the aid OF lens, agglutnated to the skin of
the potato. 1t is of an oblong form, and is
planted with the seed potato. The egg may
be hatcned in warm, moist place. The en-
tire period of development is not settled, Mr..
ID. exposed plant to the insect, under proper
precautions, and from the time of the ex-
posture to the time the young insect of the
next generation obtained his wings, was three
months. The process of reproduction has
been lngenlously watched by Mr.. Henderson,
The egg planted with the seed potato is
hatehed, 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 rest and beget-
ting the rot. While yet in the ground, and
as early as the tenth day of existence. the
young insects cohabit, and, from the great "a
pidlty with which they propagate, Mr.. II.
argues that the egg is deposited before the
hrst emergence from the ground, although, in
case OF cold, wet weather, the insect some-
times leaves the vines and returns to the tu-
Der. Only few days are required for the
entire destruction of the vine The insect ia
remarkably industrious, but the destruction
OF the vines does not affect the tuber, except
to stun its growth.
Mr. Henderson finds ready explanation
for the greater healthfulness of the potato in
sandy soil. He finds that the grains OF sand,
greatly annoy and cripple the insect, and as
tne light soil IS heaved up by the growth of
the root, the sand imparts or falls down, pre-
venting the access of the fly. In a stiff soil,
the insect leaves the ground through the
cracks opened by the growth of the tuber,
and having stung it, comes to the surface,
and attacks the vine, especially after heavy
showers. During the past winter, Mr. Hem
derson has had thousands of the young in
sects Matched under glass, and to try their
power OF mischief, has experimental with
bugs only quarter grown. The plants ex-
posed showed unmistakable sigas of disease
on the fourth day.
These statements we regard as important.
So much is evident Mr.. Henderson. by
means Of this insect, produces potato rot at
will. When a healthy plant is shown us,
the insect applied, and the rot follows in four
days with unerrlng certainty, 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 insect. The
egg being invisible any means applied should
be thorough, and reach she whole surface Of
the root. Mr.. Henderson states that by
sprinkhng quicklime over the potato as it is
cut for planting, the moisture will dissolve the
lime, and battle the tubers in a caustic alkali,
Witch will destroy the egg. We may add
that it is probably the same insect which has
recently attacked the grapevine.
since writing the above, we have found one
OF the insects in onr jar. which had deserted
the now rotten vines, at work underground
upon sound young potato.