The Richmond Virginian. (Richmond, Va.) 1910-1920, 1914-06-07
TOBACCO DAMAGE IS
BEST PREVENTED BY
ROTATION Of CROPS
Clean Cultivation Will Make
Conditions Unfavorable
For Wire Worm.

WASHINGTON, MAJ >s,--The ex-
tensive damage done by the so-called
tobacco wire worm in many tobacco
States is best prevented by crop rota-
TONS and by doing away with the
weeds which are food for the worm.
Clean cultivation should be practiced
the summer before tobacco is plant
ed. thus making conditions unfavor-
able for the egg which matches the
| worm This is the advice of the
| United States department of agricul-
lures investigators who estimate that
the damage done by the worm
amounts to $500. 900 annually in Vir-
ginia alone. and Is also great in other
| Eastern States raising tobacco The
department has Just issued a bulle-,
tin (No. 7s) on the subject, entitled:
, The So-Called Tobacco Wire Worm
in Virginia"
The growing of crops Of cowpeas
/ or crimson clover tpreferab Iv the
/ former) the year before crops sub
| 1ect TO injury are planted IL one of
the most satisfactory and practical
/ means of controlling the pest Sum
mer pIowIng and thorough prepare
! ton Of weedy land are other means
advised. The eggs of the pest are de-
posted by moths In weedy fields dur
ing July and August. They hatch In
a few days, remain over winter In the
soil, and finish their growth during
June or July Of the following year
| They are in their most active feed
/ ing stage when tobacco is planted
Injury to tobacco occurs when this
! crop Is planted on land that was
weedy during the previous year Crops
planted on land which has been an
/ der clean cultivation are immune. The
/ weeds which have been found to be
the more common natural food plants
/ OF the worm are the huckhorn plan
I tain, oxeye daisy. stickwood and
whtetop The presence of these
weeds in meadows accounts for in
/ jury to tobacco when planted on sod
The worms when once sfahlished
] IN land where their natural fond
plants are abundant have helm found
difficult to control. Various insec-
ticides and repellents have been test
ed. but without satisfactory results !
Fail or winter blowing has been /
found to reduce Injury. but is only
/ partially effective. as some of the
1 weeds remain alive and furnish food
for the larvae until the tobacco or
corn is planted
The moth from which the wire
worm is evolved is medium or rather
small in size and colored brown vel T
/ low and white, Some have metallic
marks on the fore wings which are
/ comparatively long and usually mar
! row. When raised. the fore wings are
rolled around the body and conceal
the hind wings which are folded he.
meath. This gives the body the ap-
nearance of tiny cylinder, and ac-
/ counts for the term that Is applied
to IL of CLOSE wings" These moths
I fly mostly on dark afternoons or dur
ing the early part Of the night They
are more common in open fields
When disturbed they make short
At+--Fr+ q ..s-.-4-,---.+-
4 rods at time. ~heS usually aHght
head downward on the stem Of plants
and their color often harmonizes so
perfectly with their surroundings that
they can scarcely be seen. They.
therefore. seldom attract attention
unless some important crop Is at.
/ tackled
Insect Also Attacks Corn.
The tobacco wireworm' does not
eonfine its attacks to tobacco only, /
| but Is likewise serious pest to the
/ corn crop. Injury has been noted
In many localities where little tobac- i
! CO is grown, and IT is proba Bile that I
/ damage to corn amounts to more than
/ that to tobacco AS with tobacco i
! injury is most severe to the corn
when planted on land which has been
I In weedy pasture or meadow pre- /
viousiy or when planted on land
/ which has not been under cuitiva-
ton for a number of years and on
which there has been rank growth of (
weeds. On such lands 1t is usually .
difficult to secure a satisfactory stand /
| of corn, and the yield Is greatly re-
duced In central Virginia .nany \
fields under observation We're replant-
| ed several times, and owing to the
/ lateness of the season when n stand i
was secured. the value to the crop I
was decreased fully one-third. Corn |
or tobacco planted on newly cleared !
land seldom suffers injury. Since the
( species of weeds which are the natu- I
| raj food plants OF the insect do not /
thrive in woodland. the larvae are not (
present when the crop is planted
The larvae attack the young corn
near the surface of the ground and /
burrow into the base Of the stalks. \
the outer portion of the stalk being
frequently glrdled. II the stalks are !
small when attacked. they are either
killed or so stunted or dwarfed that /
they never fully outgrow the injury i
and produce little or no grain. Much /
of the corn is attacked just after the
seed has sprouted. The larvae fire. I
quently burrow into the folded leaves
as the corn is coming through the /
ground. JAS the leaves unfold they "
show transverse rows of holes When I
the stalks reach height of a foot I
or more comparatively little damage |
is done, Several larvae are frequent
ly found about the roots of a single |
stalk and as many as twenty-tw II
have been collected from a single l
hill of corn.
In wet weather injury is not apt II
to be so severe, as the plants are /
then more vigorous. and the wees.
which furnish suitable food for the
worms, more plentiful. AS with to-
bacco, corn Is attacked when the nat
ural food supply of the worms is
cut off
The ca me aat u ode cf crrr, rata