VOL. LXVII
INDIANAPOLIS, AUG. 10, 1912
NO. 32
Insects in the Corn Field
Two Dangerous Pests .and
How to Attack Them.
FARMERS     SHOULD     START    THE
FIGHT NOW.
By   Prof.   James   Troop, Head   of   the
Department  of  Entomology,    Purdue Agricultural Exp. Sta.
Judging by the number of inquiries
which have come in thus far during
the present season, the Corn Root-
Aphis (Aphis maidiradicis, Forbes)
and the Corn Root-Worm (Diabrotica
longicornis, Say) have been unusually
abundant in many parts of the State,
i »f course, it is too late now to discuss
remedial measures for the present
crop, as they have already done all
the damage that they will do this year
N'ow, however, is a good time for the
farmer to begin planning his work for
next year so that he may be able to
overcome these Insect difficulties as
much as possible, inasmuch as the
control of the species under discussion
is largely a mater of changing the existing methods of farming. Both of
these species are more or less common
in all of the corn growing States of the
I'pper Misssissippi valley, especially in
sections where corn is the principal
crop grown, as is the case in sections
of Indiana and Illinois.
The Corn Root-Worm.
This pest ruined thousands of acres
of corn during the last thirty years for
Indiana farmers, and yet it is one of
the easiest species of insects to control, when once the farmer becomes
acquainted with its habits. Like most
insects of this class, it is useless to attempt to hold it in check by the application of poisons; it covers too
much territory, and, during the period
when it does its injury, it is concealed
'jeneath the surface of the soil. As
one becomes better acquainted with its
"fe history, therefore, the more evident it becomes that the application of
good common sense in the farming
operations is the only remedy needed.
This insect is closely related to the
Striped Cucumber beetle, belonging to
the same genus, is about the same size
and shape, but the color is a light
Kreen. The adult beetles may be
found feeding upon the silk and pollen
°f the corn during the last of July and
through August until the corn plants
approach maturity, when they lay
their eggs on the base of the stalks,
just below the surface of the soil, and
Pass the winter in the egg state. The
e8gs hatch in late spring or early sum-
mer, and at first eat the smaller roots,
"Ut, as the plants develop the larvae
"ore out the larger roots, causing the
Plants to dwindle and die, or to become so dwarfed as to amount to noth-
,nff. The full grown larvae are white,
°hunked Individuals, about one-tenth
of an inch long, and nearly as thick.
They pupate in small" oval cells in the
Ground and the beetles appear soon after.
As the larvae do not feed upon any
thing but the corn roots, It is evident
that if a regular rotation of crops is
practiced, so that corn is grown on the
same soil only once in three or four
years, there will be no chance for the
insects to increase. The trouble invariably comes from planting corn after corn, except on river bottoms,
which are overflowed several times
during each year. I have seen corn
grown on the bottom lands along the
Wabash river near Lafayette, every
year  for   the  past  twenty-eight  years,
these lice until the second or possibly
the third corn crop. If, therefore, a
three or four-year rotation is practised in which corn appears only once,
there will be but little, if any, damage
done by the aphis.
Then, too, the proper fertilization of
the soil is of great importance, as it
enables the corn to make a crop In
spite of the lice. A heavy dressing of
stable manure is generally preferable
for this purpose, according to Prof. F.
M. Webster, of the Department of Agriculture. A dressing of kainit drilled
in the row, at the rate of 100 pounds
per acre at the time of planting has
been found to almost completely protect the plants from the attacks of the
lice.    This material is used quite large-
A Thrifty Southern Corn Field That Produced  70  Bushels to the Acre.
and I have never known a crop to be
injured by this insect. But on the
upland, black prairie and muck soils,
where corn is the principal crop that
can be successfully grown, this insect
is sure to give trouble. On such land
oats and grass should rotate with
corn.
The Corn Root-Aphis Difficult to
Control.
The Aphis is a different proposition,
as it belongs to the sucking class or
true bugs, but like the other, it does
its work on the roots under ground,
and  so   ie  difficult  to  reach. These
lice are usually attended by ants, as
the latter are very fond of the "honey
dew" which is given out by the lice
through two little tubes, which are
situated on the back of the adult insect. The ants even gather up he
aphis eggs and store them in their nests
where they are cared for during winter. During April and May, as soon
as the smart-weed and fox-tail-grass
make their appearance, these eggs begin to hatch and the ants carry their
young wards and colonize them on the
roots of these plants. As soon as the
young corn plants are well started, the
second brood of lice begins to appear
and the ants transfer them to the corn
roots where they continue to increase
with great rapidity, and to suck the
life out of the corn plants.
How to Attack This Pest.
It Is evident from the above, that
*he land seldom becomes infested with
ly in some sections of this State.
As the ants protect the eggs in their
nests during winter, it is a good plan
to plow the field which Is Intended for
corn the second or third year, as late
in the fall as possible, and as deeply
as possible, in order to break up the
ants' nests. This will also assist in
destroying the weeds which serve as a
starter for the lice in the spring.
Dr. S. A. Forbes of Illinois, has
found that by dipping the seed corn in
a solution of wood alcohol and oil of
lemon before planting, the number of
lice and ants may be greatly reduced,
but this will prove true only when the
weather conditions are just right. If
heavy rains follow the planting, the
material is washed off and so loses its
force. With our present knowleiige,
therefore, rotation, late fall plowing,
early and thorough cultivation, and
the use of kainit are all recommended.
Note especially that the best remedy
applies to both of these species, viz.,
frequent  rotation   of  crops.
A VISIT TO THE STATE FORESTRY
RESERVE.
Experiments That Will Reneflt Indiana
in the Future.
Thursday, July 25th was "Visitors'
Day" at the State Forest Reservation,
which is located in Clark county north
of Henryville. For the past three
years it has been the plan of C. C.
Deam, Secretary of the State Board of
Forestry, to set aside one day in July
upon which he invites all who are interested in any way in the growing of
trees to pay the reserve a visit. The
grounds are open to visitors at all
times, however, and by notifying the
secretary, or Mr. Waterman, warden
of the reserve, the visitor will be met
by a guide, any day except Sunday,
and will be shown about the grounds.
Work Done on Poor Land.
Some far-reaching and unprejudiced
experiments in the culture of forest
trees are being conducted upon this
tract of which comparatively few people of the State are acquainted. The
State Reservation consists of a tract of
2,000 acres of poor, rough, setfond
growth timber land. The surface of
the land for the most part is too broken for agricultural purposes, and the
soil, known as knobstone shale, is a
heavy unproductive clay. If left un-
tended for a few years such land becomes a mass of briers, sassafras,
chestnut oak and the like and is an utter waste. Yet there are in our state,
particularly in the southern portions,
many thousands of acres of such land
that could be made to yield a profit in
a few years when judiciously planted
to the proper varieties of trees. It is
the purpose of the State Reservation to
determine these things, and it is for
this purpose that the state appropriates annually  $3,000.
.Selection of Suitable Varieties.
Already many valuable things have
been learned. An attempt has been
made to grow chestnuts and pecans
but the results have proven unprofitable from a commercial standpoint.
We are too far north for pecans but
some places along the lower Wabash
valley these nuts are grown. Even
here only about 25 per cent of the
trees  bear.
In determining the most suitable varieties of trees to grow some interesting things have been done. Black
walnut was planted on poor and fairly
good soil. The planting on the poor
land, although all was planted at the
same time and received the same treatment, is but a third as large as that
upon the good land.
Best Varieties for Indiana.
The black locust, catalpa, white ash
and yellow poplar seem to do best and
for several reasons. Mr. Deam grows
them extensively. The black locust
does well on poor soil, does not respond well to cultivation and when
planted close together, 6 to 8 feet apart
each way, will in a measure prune
themselves. The lower limbs being
shaded die and drop off leaving a
straight tree trunk. One planting has
been cultivated while near by is another that has received no such aid
but they seem to be doing equally
well.
Mr. Deam likes the white ash and
yellow poplar because they are two of
the valuable trees that grow rapidly,
are good for both commercial and ornamental purposes and are easily managed. They can be grown at less cost
than other similarly classed trees, and
this is an important consideration in
forestry for interest on money invested
in preparing the ground and in planting will, by compound interest, amount
Continued on  page 8.