Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-06-17

/ PROF. RILEY ON THE LOCUSTS.
A Bulletin On the periodical Cicada''-
| Their Strange Habits-The Ruin They
| Work I'm Orchards.
Prof Riley, entomologist of the Agricultural
| department, has prepared bulletin on the
| periodical cicada," which will soon be pub
| lished. 1t is pronounced the most complete and
| comprehensive treatment of the subject ever
undertaken. At the outset Prof. Riley says:
| "The metamorphoses of insects, their in
| structive industry, their quarrels and their in
| stincts afford abundant food for our love of the
| marvellous; but few species can claim such q
| singular history can our periodical cicada We
| are moved to admiration in contemplating the
fact tn at an insect after living for nearly
last ascend from it's earthly retreat, change its
| sluggish, creeping and wingless form, and, en-
a CO., With the power OF fight become deni-
| sun. But our wonder increases when we reflect
| that this same insect has appeared in some
part or other of the United States at regular in
tervais of seventeen years for centuries-aye,
| for ageS-in the past! Long ere Columbus trod
American soil this lowly insect must have APP
peared regularly ut it, appointed time 1t must
have filled the woods with its rafting song
| when none but wild beasts and savages were
present to hear ii. To me there is something
| pleasant in the idea that through its periodicity
! we are enabled with tolerable certainty to go
back in thought, for centuries in the past, to q
| particular month of particular year, or even
| to given day, when the woods resounded with
\ Its song In the same manner as they did in
1868, or will the present year."
SEVENTEEN AND THIRTEEN YEAR LoCUSrS,
1t was my good fortune to discover that be-
sides the seventeen-year broods, the appear
ance of one of which was recorded as long ago
as 1888, there are also thirteen-year broods
| and that, though both sometimes occur in the
| same states, yet in general terms the seventeen
year broods maybe said to belong to the northern
and the thirteen-year broods to the southern
states the dividing line being about latitude
80 degrees. though in some places the seven
teen-year broous extend below this line W lille
in Illinois the thirteen-year broods runs nm con
siderably beyond it.
1t so happened that one of the largest SEVEN
teen-year brOOdS, together with of the
largest thirteen-year broods. appeared simulta-
neOusy in the summer of S6S. Such an event
ad Tar o as na these broods
will 1t take place again until the year 2Os9.
There are absolutely no perceptible specific
differences between the seventeen-year and the
thirteen-year broods, other than in the time of
maturing but while the insects forming these
tmc tssS OF 6roods are not specifically ds
do not cross, and have, therefore, for conve-
nience sake, named the thirteen-year broods
Prot Riley sets forth that two distinct forms
occur In both races, large one and u small
one-the former being the more numerous The
large form measures, on an average, HI inches
from the head to the tip of the closed wings
and almost always expands over three inches
The other or smaller form is not, on an average,
more than twO-thrds as large, and the two are
differently marked. There are sufficient differ
ences to separate the two forms as distinct. The
large form has been observed to make its ap-
pearance from eight to ten days earlier than the
small form.
THE SEASON OF THEIR APPEARANCE AND DIS
APPEARANCE.
The season of their appearance and disap-
pearance differs somewhat with the latitude,
though not so materially as one might suppose.
According to the records, they appeared in
1868 earlier in the south than in the north but
the last half of May can be set down as the
period during which they emerge from the
ground , IN any part OF the country, while they
county, Mo-, in 1868, they commenced issuing
on the 22d of May, apd by the 2sth of the same
month the woods resounded with the rafting
concourse of the perfect insect. AS is the case
with a great many other insects, the males
make their appearance several days before the
females, and also disappear sooner Hence in
the latter part of the cicada season, though the
woods are still full of females, the song of but
very few males will be heard.
Circumstances, Prof Riley says,may accelerate
or retard their development, as was proven in
ing underground flues for forcing vegetables
caused the cicadas to issue as early as March
2Oth, and at consecutive periods afterwards till
individuals did not sing. They frequently APP
pear IN small numbers, and more rarely in
large numbers, the year before or the year after
the case with the thirteen-year brood. It has
been discovered that. in places, particu-
their galleries places OF residence in the earth
rom I9ur 70 SIX inches above ground leaving
an o5ss OF n egress with the surface In
would be found awaiting their approaching
time Of change. These holes are cylindrical
and are evidently made by expressing the
earth on all sides and throwing the refuse to
the bottom, which must be quite a feat when
they penetrate hard roads or come up between
Two rocks, as they frequently do. The larvae
are frequently found at a great depth notwith-
standing the denial of the fact.
Prof. Riley gives instances where they have
peen found ten feet below the surface.
THE TRANSPORTATION.
When ready to transform they invariably at
tach themselves to some object, and, after the
fly has evolved, the pupa skin is left still ad-
herring. The operation of emerging from the
pupa most generally takes place between the
hours of and p. m; and ten minutes after
will entirely have freed itselffrom it. Immedi-
ately after leaving the pupa skin the body is
soft and white, with the exception of two black
veloped in less than an hour, but the natural
colOrs of the body are not acquired till several
n noafs nave elapsed: These recently developed
transforming, but soon become more active, both
In Hight and song, as their muscles harden.
they are true ventrloquists, their rattling noise
being produced by a system of muscles in the
lower lower part OF the body which works on the
ing and loosening them. The general noise on
approaching the infested woods, is a combina.
ton OF that OF a distant threshing machine and
distant frog pond, That which they make
when disturbed mimics a nest of young snakes
or young birds under similar circumstances
sort OF scream. They can also produce q chirp
somewhat like that OF q cricket and q very
loud, shrill screech. prolonged for fifteen or
twenty seconds, and gradually increasing in
force and then decreasing. After pairing, the
females deposit their eggs In the twigs of differ
ent trees, and though for this purpose they
seem TO prefer the oaks and the hickories they
oviPosit In almost every kind of deciduous tree,
and even in herbaceous plants and in ever
green's.
The eggs hatch between the Goth of July and
the lst OF August, or in about six weeks after
being deposited. The newly-hatched larva diff
iers considerably from the full-grown larva bu-
principally in having much longer and dist
tinctiy eightjointed antenne. It is quite ac-
tive, and moves its antennfe as dexterously and
as rapidly as does an ant AS soon as it has ex-
tricated itself from an exceedingly fine men,
brane 1.-THE amnion), which still envelops 1t after
1t has left the egg, our little ccada drops DELHI
erateiy to the ground, its specific gravity being
so insignificant that it falls through the air as
gently and as softly as does O feather.
THE SUPPOSED STING OF THE PERIODICAL