Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1874-10-22
The Migratory Grasshoppcr.

ing this predatory and destructive in
sect:
Nearly all who have written anything
| about the migratory grasshopper (CdtoI-
te7.us Spretusl unite in locating its head
quarters among the canons Of the Rocky
Mountains. From these, we are told
upon good chronological authority, come
the swarms that occasionally invade the
States west of the Mississippi, and
whose progeny are said to be barren and
to fly away no one knows whittier, the
next invasion coming as before from the
Mountains. This theory is absurd be-
cause the reserve force, supposed to re-
main in the mountain canons, must con-
stantly suffer depletion and finally
become extinct through sending forth
such immense swarms that never return,
and whose barren offspring disappear
entirely. Having given some attention
to the study of insects, and having made
this grasshopper my particular study
during its visit here, am convinced that
| its home should be sought upon the
plains of Texas and New Mexico or per
| haps farther south, and that all broods
are equally capable Of reproducing their
kind, as the following observations will
tend to show:
In 1873 immense swarms OF this grass
hopper arrived here about the last of
May. They were flying in a northerly
direction, and halted on account Of wet
weather, and probably adverse winds.
| They remained, doing considerable dam
age to young wheat, for several days be-
| fore continuing their journey to the
north. In the meantime they deposited
many eggs, which soon Matched; and the
| iU mi
nearly all the corn, oats and vegetables.
This much have upon popular report.
| When / came here, Aug. z, 1878, they had
had their wings for some time, but the
wind being constantly from the south
they remained until Aug. 16, upon which
day-a fresh northerly breeze having
| sprung up during the night-they nearly
all departed toward the south. From
| time to time thereafter, whenever the
wind blew from the north on clear day,
the sky would be filed for hours, as with
snow6akes, by grasshoppers coming from
| farther north and passing over. A few
occasionally alighted, and we had more
| or less Of this species until frost killed
| the remnant. Some eggs were deposited
here, and these do not appear to have
| been damaged by the winter. This
spring was rather cold, and the eggs did
not begin To hatch until May 10, after
two weeks OF warm weather. The larvae
came out rapidly, and were soon rather
common in wheathelds and gardens.
| saw no perfect specimens until May
30. After the wind had blown very
strong from the south and southwest for
four consecutive days / found winged,
migratory grasshoppers quite plenty.
These must have come from some dis
lance south, and, il they had developed
no faster than the same species did here,
must have left the egg about April 10.
A few days later, about June 2 most Of
those that were Matched here became
pupe, In which condition they differ
from the perfect insect In having small
pads instead of wings June 20 some
Of them cast the pupa skin, and in u few
days all had wings. AT this time they
were Of light color, and seemed, for
several days, quite unable to fly more
than a few feet. They soon deepened i'm
color and acquired strength, and about
June 30 nearly all rose and went south
with northerly wind. After this date
the experience of the former season was
repeated. On every clear day, when the
wind blew from the northwest or north
east, more particularly the latter, innu-
|
passed over, going south, and up TO the
present date multitudes may be seen
when the wind and weather are favora.
BILE.
Now, as this grasshopper Is found 10
come here from the south in spring, and
from the north In autumn, but never
from the west, ! infer that its native
home is in the far South, where 1t ma.
lures early in the season, and gets here
In time to raise second brood the same
year.
Rev. Cyrus Thomas, good authority
upon grasshoppers, gives 1t rs his opin.
ion that "the native abode and breeding
place of the insect is in the mountain
valleys and canons;" but he thinks that
they "do not cross the plains from the
mountains in one season." He seems
to think that they cross by successive
broods, but certainly no brood from the
west could have arrived here as early as
did that in the spring of 73, or the indi
viduas that ] saw May 80, "a. Those
that went north in the spring of '73 and
those that came from the north in the
fall of the same year deposited fertile
eggs; and, as one of these broods must
have been the parent of the other, the
theory that broods reared on the low
lands are barren is destroyed. The
young go back on the same route taker
by their parents and are therefore not
lost. Another popular error is that the
course of this insect Is determined by the
wind 1t, indeed, always flies with the
wind, although it rises against it, but i
always determines its course by migra
ton Independently Of the wind, and ther
waits for favorable breeze before
taking flight For instance, If the grass
hoppers desire to go south, they wait fo
: a northerly wind, and until such wine
arises not grasshopper will travel
They may frequently be seen high in thu
air when adverse winds are blowing, bu
: they only fly wildly about for shor
: time and then descend. In like manner
if they halt while on their way north
! nothing but south wind will NOV,
them on.
1t would be interesting to learn how
far south these grasshoppers go. Canno
some of your readers who reside IL
Texas enlighten us upon this point?
The difference between IA fool and
, look in o.. glaes 10 said tn he that the foo