Weekly expositor. (Brockway Centre, Mich.) 1882-1894, 1885-06-04

together. The fourth, fifth, sixth and seventh
joints sub-equal. Ten of the eleven joints are
plainly marked, when viewed with hand
glass. Head and thorax, black, dull, punctate,
rugos and covered, though not densely, with
Tine gray hairs. Abdomen, shining black,
polished, sparsely hairy; as long as head and
thorax together, and larger than the thorax.
The antenn@, including scape mouth parts,
head, abdomen and thorax, except small,
rounded, lght-colored spot on the pronotum,
back of the eyes, are pltchy-blaek. The troch-
anters, femora, middle and posterior
tibi@, black The anterior tibia
tibio-femoral joints, one-third of distal end of
anterior femora, and tarsi are yellowish-brown.
In some eases, the distal ends of the tarsi are
dusky. The legs are thicKly pilose. The wing
veins are honey yellow, and extend to outer
third OF wing. Sub-margnal vein three times
as long as marginal; marginal nearly twice as
long as post marginal; post marginal and stig-
NAL slb-equal Described from more than 100
specimens. Wings in all perfect. Variations
very slight.
The eggs are white; rs to 100 in number; /
m. m. long; and each with pedicel two-and-
half times as long as the egg.
MALE: Length of body IN. IN. expands 8.
s IN m. ; greatest width of front wing /. IN.
IN. antenne sub-cylindrical: longer than In
the female; with more and longer hairs; the
last seven joints sub-equal. Thorax and abdo-
men as in the feml ale, except that the pronotal
spot Is wanting or very obscure; the abdomen
slightly peduncled, shorter and hardly larger
than the thorax. Celebration OF body and APP
pendages same as In female. Venatian similar
to that of female. The wings in both sexes
are margined with hairs, which are rather
coarse along the marginal and post-marginal
veins. The general surface Of the wings show
numerous short hairs. The male are nearly
as numerous as the females, and all have per-
feet wings.
length IN. M jaws dark, without teeth. The
antenne are short, one-jointed, tubercles of
the same color as the body. Very few hairs.
Stigmata very obscure.
PUPA.-ln autumn and winter white; In late
spring black. Length A. IN. IN male 32 m
IN. In autumn the wing pads are very indis-
tinct, hardly visible; but in spring they are
plainly marked.
COMPARED WITH OTHER SPECIES.
This insect is very different from the /. tri-
tici (Riley), in being much larger, In its black
black scape in antenna black mesoscutum,
black coxe, light instead of yellow pronotal
spot; the numerous males, and the fact that
all are winged. These work to the number Of
from five TO fifteen at one place in wheat
stems, instead of one or two, and the
stalk solldfes. The larve has no teeth
on its mandibles, and only one joint to
the tubercle-lke antenne. 1t differs from /.
grande (Riley), but little in size; but in other
respects the points of difference are much as
above.
From the old joint worm Of Fitch e. hordei
IilNu), IL III btluS idiStI, III udfluk a.
black scape to antenna, black mouth parts,
and in working in greater numbers in single
straw In causing the straw To solidify, in not
forming swelling and in working any where
on the internodes Of the straw.
From /. elymi (French) Ii differs In being
much larger, and the legs are not so fully fus-
cous. /. elymi works in grass, which Is prob
ably true also of this species, yet they must be
quite distinct, as shown by sizes.
NATURAL HISTORY.
From what we know of related species, and
from the fact that all the internodes (spaces
between the joints) are attacked, or receive
eggs, il Is quite certain that the eggs are laid
late in May and in June. BY September the
larvae are matured / found several pupe in
the cells of tie straw ON September 16. found
a few larvae in January. Ii would seem, then,
that few OF the insects pass the winter In the
larval state. Specimens kept I'm warm room
all winter, commenced TO leave the cells in the
wheat stalk, as mature insects, on March %
Each succeeding day ever since from two to
eight have appeared. From straw kept IL a
cold room during the winter, no flies have ap-
peared until April 20. II is likely that in the
common outdoor temperature they would not
come forth from the pupa state till May.
This point can be easily settled IN the
field the coming season. This and the
date and method Of laying will have
TO await determination till the insects can be
studied in the field the coming May. The
method of oviposition is undoubtedly much
like that of !. grande and !. tritic, as descibed
by Mr.. +. NJ Webster (see Report Department
OF Agriculture 1884 page 1881, and DIR. G. "
Riley in the same volume, page 1853.
PROBABLE HARM.
II We may Judge IRON the related insects,
ls0soma hordei, or lsosoma tritici, we may be
quite certain that the damage from this insect
may become formidable If, as l think, the
insects referred to by Prof. Lintner are Of this
species, then we have positive evidence that
they lessen re yield of wheat very materially.
Indeed, we cln hardly believe that so many
larvae can draw from the juices of the. stalk
without doing it serious injury. The harden
ing of the stal k can but retard circulation of
sap, and must interfere decidedly with the
growth and development of the berry. Sew
eral farmers have told me that from appear
ances the yield OF grain in their fields should
have been much larger. They could not ac-
count for the diminished yield except by the
presence of this insect, which was very com
mon, as seen in the numerous hardened pieces
OF straw which came from the machine 1t
is therefore greatly TO be feared that this new
pest will become serious enemy to success
full wheat raising, especially as from a large
number | have reared but a single parasite,
which as yet Is undetermined Even II 1t be-
comes very destructive, 1t Is more than prob
able that parasites will soon attack it, and
that, like the joint worm, lsosoma hordei, IL
will after time become powerless to work
very serious mischief.
REMEDIES.
The remedies for this evil are very apparent
AS the insects are in the straw from the date Of
cutting till the following May, it becomes very
apparent that by cutting the wheat high, in
which case nearly all the insects will remain In
the stubble, and then burning the latter, all
these will be destroyed. In case there is much
green vegetation, it would be better to cut the
stubble low before burning. II short pieces Of
straw are found in the grain. these should be
cleaned out and burned. From experiments
made I'm the laboratory by buryinp the straws
in sand, and the insects still coming out
doubt IL blowing under will prove a very
thorough remedy. As these have fully-devel-
oped wings, rotation of crops would not serve
as well to protect against this insect, as II
would In case of /. trtici and l. grande.
THE Law MAKERS.