344 
THE RURAL NEW-YORKER. 
CtitomrrUgkal. 
THE BLACK WHEAT STALK ISOSOMA. 
ISOSOMA NIGRUM N. S. 
PROF A. >T. COOK. 
Early last Autumn, I received from Mr* 
ffm, Deyo, of Denton, Wayne County, Miehi 
gan, specimens of wheat straw which con¬ 
tained from five to sixteen larva' of a four¬ 
winged (Hymenopterous) fly. The portion 
attacked was usually near a joint , but might 
be anywhere along the internode, and was 
found above every joint, though very rarely 
above the highest one. The immediate region 
of attack was creased and deformed, (Fig. 170), 
Fig. 170. 
Black dots show place of .exit of fly. 
though not swollen, and was very hard, so 
that to cut it, except with a very sharp knife, 
was difficult. At this portion of the stalk, 
which was usually from three c. m. (one-and- 
a-fiftb inch) to five c. m. (two inches) long, 
the straw was not hollow but solid through¬ 
out. By cutting into this deformed straw, 
the yellowish-white larvae were found in oval 
cells. These cells were about four m. m. 
(.16 of an inch) long. I published an 
account of this fact in several papers of 
Michigan and other States, (see Country 
Gentleman, Vol. 49, p, 817) askiug for further 
information. In response to these inquiries, 
I received several communications from 
Wayne and Washtenaw Counties, Michigan, 
in both of which the insect worked exten¬ 
sively. 
So far as I can learn the insect has never 
been noticed before; and as the hardened 
pieces of straw break off in thrashing and 
come out of the machine with the grain, their 
presence could bardly escape attention. Mr. 
l. S. Vandervort, of Ypsilanti, Michigan, to 
whom I am indebted for many specimens, 
says the attack was quite general in Washte¬ 
naw County, and that the short straws in the 
grain had been noticed and commented upon 
by man 3 r farmers who had not even mistrusted 
that insects had anything to do with it. At 
our Farmers’ Institute held at Plymouth, in 
January, I found hardly a farmer who had 
not been vexed by the small pieces of straw, 
yet not one had discovered the cause. 
In the Country Gentleman, Vol. 49, p 857, 
Prof. J. A. Lintner refers to similar attacks of 
wheat in New York, and says the cause is the 
same species that has doue so much damage 
in Illinois and south—Isosoma tritici: yet 
from the brief description, I think it far more 
likely that lsosoma nigrum is the insect which 
is doing the damage in New York. The farm¬ 
ers in Wayne aud Washtenaw Counties are 
not sure that the damage was very great, 
but all reported the wheat yield below their 
expectations. Prof. Lintner estimated the 
loss in New York to be from 60 to 75 per cent, 
in such stalks as were attacked. 
DESCRIPTION. 
Isosoma nigrum, N. sp. Female (Fig. 171). 
Length of body, 4.4 m. m.; expanse of wing, 6.5 
m. m,; greatest width of anterior wing, LI m. 
m.; antenna; sub-clavate, somewhat pilose, 
reach to middle of thorax. The scape is a little 
less hairy, aud as long as the two following 
joints together. The fourth, fifth, sixth and 
seventh joints sub-equal. Ten of the eleven 
joints are plainly marked, when viewed with 
a hand-glass. Head aud thorax, black, dull, 
punctate, rugose and covered, though not 
densely, with fine gray hairs. Abdomen, 
shining black, polished, sparsely hairy; as 
long as head and thorax together, aud larger 
than thorax. The antenna, including Bcape, 
mouth parts, head, abdomen aud thorax, ex¬ 
cept a small, rounded, light-colored spot on 
the prouoturn, just back of the eyes, are pitchy- 
black. The trochanters, femora, middle and 
posterior tibia, black. The anterior tibia, 
tibio-femoral joints, one-third of distal end of 
anterior femora, and tarsi are yellowish- 
brown. In some cases, 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-marginal vein 
three times as long as marginal; marginal 
nearly twice as long as post marginal; 
post marginal and stignml sub-equal. Des¬ 
cribed from more than 100 specimens. Wings 
in all perfect. Variations very slight. 
The eggs (Fig. 172)are white; 75 to 100 in num- 
Fig. 172. 
ber;l m. m. long; and each with a pedicel two- 
and-one-half times as long as the egg. 
Male: (Fig. 173) length of body 3 m. m.; ex¬ 
pands 5.8 m. in.; greatest width of front wing 
1.3mm.; antennae 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 female, except that the pronotal 
spot is wanting or very obscure; the abdomen 
slightly peduncled, shorter and bardly larger 
than the thorax. Coloration of body and ap¬ 
pendages same as in female. Venation similar 
to that of female. The wings In both sexes 
are margined with hairs, which are ruther 
coarse along the marginal and post-marginal 
veins. Tbe general surface of the wiugs show 
numerous short hairs. The males are nearly 
as numerous as the females, and all have 
perfect wings. 
Larva. — The larva (Fig. 174) is yellowish 
Fig. 174. 
m.—Mandible, 
e.—Antennas. 
straw, in causing the straw to solidify, in not 
forming a swelling and in working any where 
on the internodes of the straw. 
From I. elymi (French) it differs in being 
much larger, and the legs are not so fully fus¬ 
cous. I. 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 thB internodes (spaces 
between the joints) are attacked, or receive 
eggs, it is quite certain that the eggs are laid 
late in May and in June. By September the 
larva? are matured. I found several pupa? in 
the cells of the straw on September 16. I 
fouud a few larva? in January. It would seem, 
then, that a few of the insects pass the Winter 
in the larval state. Specimens kept in a warm 
room all Winter, commenced to leave the 
cells in the wheat stalk, as mature insects, on 
March 22. At that date a male and female 
appeared. Each succeeding day ever since 
from two to eight have appeared. From straw 
kept in a cold room duriug the Winter, no 
flies have appeared until April 20. It is 
likely that in the common out-door temper¬ 
ature they would not eotne forth from the 
pupa state till May. This point can be easily 
settled in the field the coming season. This 
aud 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 I. graude and I. tritici, as desorib 
ed by Mi*. F. M. Webster (see Report Depart¬ 
ment of Agriculture, 1884, page 388), and Dr. 
C. V. Riley in tbe same volume, page 358. 
Fig. 175. 
PROBABLE harm. 
white ;leugtb 4m.m.; jaws dark, without teeth. 
The autennoe are short, oue-jointed, tubercles 
of the same color as the body. Very few 
hairs. Stigmata very obscure. 
Pupa (Fig. 175).—In Autumn and Winter 
If we may judge from the related insects, 
Isosoma hordei. (see Fitch, 7th report, p. 162) 
or Isosoma tritici (see Forbes 13th report, 
State Entomological Illinois, p, 30, and Riley 
Report, United States Department of Agri¬ 
Female Isosoma Nigrum, N. Sp. (Magnified 10 Diam.) Fig. 171. 
white; in late Spring black. Length 4.1 m.ui.; 
male 8.2 m. in. In Autumn the wing pads are 
very indistinct, bardly visible; but in Spring 
they are plainly marked. 
COMPARED warn OTHER SPECIES. 
This insect is very different from the I. tri¬ 
tici (Riley), (first described in the Rural 
New-Yorker of March 4, 1883), in being 
much larger, in its black scape in anteunne, 
black mesoscutum, black coxtc, 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, 
culture, 1881-2, p. 183), we may be quite cer¬ 
tain that the damage from this insect may be¬ 
come formidable. If, as I think, the insects 
referred to by Prof. Lintner, are of this spe¬ 
cies, then we have positive evidence that they 
lessen the yield of wheat very materially. In¬ 
deed, we can hardly believe that so many 
larvae can draw from the juices of the stalk 
without doing it serious injury. The harden¬ 
ing of the stalk can but retard circulation of 
sap, and must interfere decidedly with the 
growth and development of the berry. Sev¬ 
eral farmers have told me that from appear¬ 
ances the yield of grain in their fields should 
Male Isosoma Nigrum, N. Sp. (Magnified 18 Diam.) Fig. 173. 
and the stalk solidifies. The larva has no 
teeth on its mandibles, and only one joint to 
the tubercle-Jike antenna?. It differs from I. 
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 (I. hordei. 
Fitch), it differs in belug larger, in having 
a black scape to antenna, black mouth parts, 
and in working in greater number* in a single 
have heen much larger. They could uot ac¬ 
count for the diminished yield except by the 
presence of this insect, whicu was very com¬ 
mon, as seen in the numerous hardened pieces 
of straw which came from the machine. It 
is therefore greutly to be feared that this new 
pest will become a serious enemy to success¬ 
ful wheat raising, especially as from a lurge 
number I have reared but a single parasite, 
which as yet is undetermined. Even if it be¬ 
comes very destructive, it is more than prob¬ 
able that parasites will soon attack it, and 
that, like the joint worm, Isosoma hordei, it 
will after a time become powerless to work 
very serious mischief. 
REMEDTK8. 
Tbe remedies for this evil are very appar¬ 
ent. As the insects are in the straw from the 
date of cutting till the following May, it be¬ 
comes very apparent that by cutting the 
wheat high, in which case nearly all the in¬ 
sects will remain in the stubble, and then 
burning the latter, all thesB will bo destroyed, 
lu case there is much green vegetation, it 
would be better to cut the stubble low before 
burning. If short pieces of the straw are 
fouud in the grain, these should be cleaned 
out aud burned. From experiments made in 
the laboratory, by burying the straws in saud, 
and the insects still coming out, I doubt if 
plowing under will prove a very thorough 
remedy. As these have good, fiilly-dBveloped 
wiugs, rotatiou of crops would not serve a3 
well to protect against this insect, as it would 
in case of I. tritici aud I. grande. 
The drawings were made from life by my 
special student in entomology, C. P. Gillett. 
Agricultural College, Lansing, Mich. 
IS THE WOOLY APHIS INVULNERABLE? 
I must enter a protest against keeping before 
the public view* the remedies prescribed by the 
insect-doctors, against the aphis whether soft- 
soap, whale oil soap, kerosene emulsion,or bisul¬ 
phide of cavbou. It is just as sensible to say 
“Catch them, aud cut their heads off with a 
hatchet.” To be sure, you may kill a great 
many of them, but the lice can stand about as 
much of these medicines as the trees—there 
are always euough left for “seed." They mul¬ 
tiply incredibly fast, and if you discontinue the 
treatment the aphides swarm again—follow 
them up and the trees die. 1 will venture the 
assertion that no orchard of considerable size, 
once iufested, has ever been cleared of the 
aphis by auy of these so-called remedies. 
They are not practical. If I am correct, 
what is the use of continuing this farce in all 
the horticultural periodicals aud textbooks of 
telliug how to eradicate them? The above 
remarks will also apply elsewhere—for in¬ 
stance, bauds for trapping the larvm of Cod¬ 
ling Moths: lights to attract the moth itself, 
aud I am not so certain yet about the “arsen¬ 
ic” remedy, so I will suspend judgment until 
another year’s trial, benjamin buckman. 
Sangamon Co., Ill. 
farm 
AN EFFICIENT POTATO PLANTER. 
One of the most laborious operations in the 
whole process of potato-raising is that of 
planting, and particularly, that of dropping. 
To carry over the soft ground, all day on one’s 
arm or shoulder, a bag or basket containing 
half a bushel or more potatoes makes the 
Carrier glad to see tbe sun go down, and he 
is usually too tired to sleep; auil wo are glad 
to chronicle the iuveutioa o( a machine w*hich 
performs the whole process of opening the 
furrow, dropping the potatoes, applyiug the 
fertilizer and covering them atone operation, 
aud by horse-power, and does the work well. 
That our readers nmy get a good idea of its 
construction aud manner of working, we 
show at Fig. 176(Page815) the AspimvallFIaut- 
er. As will be seen, it is designed for two 
horses—is mounted on a substantial pair of 
wheels 34 inches in diameter. Tbe frame is u 
single casting to which the tongue is bolted. 
On the tongue is au adjustable marker, which 
is easily turned from side to side at the end of 
the rows, aud is held by a clutch iu au upright 
position while turning. The opeuing plow or 
furrowor is ruuuer-shaped, as shown, aud is 
held in the apex of a V-shaped, wrought-irou 
frame, which is hinged at its broad part to 
the real* end of the main frame, and the depth 
at which it opens the trench is regulated by 
a lifting bar at its extreme front point, as 
shown. It is necessary that this plow be ruu- 
ner-shaped, so that it will open a furrow to a 
sufficieut depth—from four to seven luches— 
without tearing up iuverted sods. The cov- 
erersare attached to crooked arms which are 
pivoted near their center to the V-shaped 
frame of the plow, and the front end is 
attached to the frout end of the main frame by 
au adjustable bolt aud the depth to which 
they cover is regulated by this bolt. Besides 
this, the coveror blades are very narrow, al¬ 
lowing any excess of dirt to pass over. Beiug 
pivoted to the plow frame near the center of 
each, they uro controlled by the plow, aud 
when that is lifted at the end of the rows, 
they are also elevated entirely clear of the 
soil. 
The hopper is of wood capable of holding 
nearly a barrel of seed, which is held by an 
adjustable gate aud allowed to pass down into 
