The Richmond palladium and sun-telegram. [volume] (Richmond, Ind.) 1907-1939, 1908-07-23
Much Trouble Has Been En-
countered in Thresh-
ing This Year.
INVESTIGATION is MADE.
ENToMoLoGIST OF PURDUE UNI
vERSlTY MAKES INNESTIGA-
TIoN AND TELLS OF IT'S WORK
AND PREvENTATtvEsM

Much trouble has been reported
since the threshing season began as a
result of the wheat-joint worm, and
the fact that it has ruined a great
deal OF straw. Farmers in the vicin-
ity of Greensboro were the first in this
county to make complaint against the
effects of the insect. The straw is
damaged SO that thrashing it breaks
1t into small bits and is difficult to
separate from the grain. This year is
is the first time the insect has been OBJ
served in this county. AS the result
of the effects of the insect a large
quantity of the straw from this season
threshing will be practically worth
less
An investigation of the insect and
its effects has been made by J. Troop,
the agricultural experiment station is
as follows:
The wheat joint-worm belongs to
the family Chalcididae, one of the
families of parasitic Hymenoptera,
which are generally classed as bene-
fetal, but this species IS an exception
to the rule. The adult insect is only
about one-eighth Of an inch in length
Color black, with the joints Of the legs
and feet yellow. Professor F. M. Web
ster of the department Of agriculture,
Washington, D. c., says OF its life his
tory: 1.-THE insect may be found
throughout the year in its various
stages of development in wheat stems.
1t lives over winter as larva or grub
in cells formed in the stems prior to
the ripening of the grain, the adult
emerging therefrom in April or May,
according to latitude, or sometime af-
ter the young grain has thrown up
stems and several joints have become
exposed.
The female using her slender point
ovipositor, places her eggs in the
straws. The eggs hatch and the young
grubs, forming cells, feed in the walls
of the stem, reaching their maximum
growth by the time the straw becomes
fully hardened and ripe. Wintering
in the larval state, they pass a short
pupal stage and emerge as adults in
the spring."
The effect on the straw is to distort
1t into various shapes, and at thresh-
ing time the infested parts become
hard and dry and break up into small
pieces which are difficult to separate
from the wheat. Many farmers are
anxious to know whether these insects
will injure the grain in the bin, but
there is no cause for uneasiness on
this account. as they only work in the
stem, thereby causing the kernels to
become small ad shrunken.
Natural Enemies.
Like most of our Injurious species,
this one has number of parasitic
species which feed upon it, and which
serve to hold it in check. This will
doubtless prove to be the case in this
instance, so farmers should not hest
tate to continue to SOW wheat. But
there are some
Preventive Measures.
which shauld be practiced where pos
sible, such as burning the stubble,
where the fields have not been seeded
to grass or clover. Using the straw
for bedding for stock and piling the
manure for some time until it has be.
come well heated will have a tenden.
cy to develop the insect prematurely
Rotation Of crops and using plenty
of quick acting fertilizers are some OF
the measures indicated.
This insect in larval form may
be quite easily mistaken for the wheat
saw-hy borer (cephas pygmaeus Linn.)
which belongs to different family
and whose life history is quite differ
emit from Isosoma tritici.