Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1919-08-09
Scientific Discussions
BY Garrett P. SeruisS

The voice of the cicada, or seven
teen-year locust" is again heard in
the land. Probably it is audible
somewhere, here or there, almost
every year, but when the concerts
break forth near such Il ctnter of
human population as New York, this
most remarkable insect is able,
literally. to command attention.
Moreover, when it fills the air with
countless, buzzins hosts it recalls
images of the merciless march of de-
stroying armies. vivitied by the
mystic w" that 1t bears on its wings,
and that has been interpreted by n
certain type of mind as an omen of
coming war. The formidable big
ness of the insect. its bristling look,
broad beetle brows, heavy body and
hooked limbs, together with it's red
eyes and red-veined wings, all in
crease the somewhat terrifying i'm
preston that ii makes.
1t is Il drummer, too-another re-
minder of wars alarm. The sound
of its drum is shrill and high pitch
ed. such as would be expected at the
head of an army of insects, but it's
reach is far beyond the usual range
of insect sounds. 1t can be heard
at times quarterJor perhaps even
half-mile away, when thousands
OF the males are drumming in con-
cert. The females have no drums,
or other musical or vocal instru-
ments, and l am not aware that any
certain organ of hearing has been
recognized in their anatomy-but
hear in some manner they surely
must.
The drum consist of pair of
tEhtly-stretched membranes cover
ing small cavities at the base of the
thoraX, and these membranes are
set into vibration, not by blows from
the exterior, but by the rapid action
or special muscles attached to the
inner surface. In truth, if natural
lists are rights the piercing sounds
thus produced are not warlike in am
sense, but are love songs. When
heard not too near, on warm
drowsy summer afternoon. they
have seductive quality even foI
the human ear, and make an ad-
mlrable prelude to a siesta.
The cicada perhaps. the Longest
lived OF all insects. But the seven.
teen-year variety shows no great
tondness for our upper world, into
which 1t emerges from under GROUND
merely for a very brief honeymoon
which lasts only few weeks. Fol
the cicada, not only are matche.
made in heaven, but weddings, too
are performed there (for the worlc
OF sunshine must be kind o.
heaven to iD, and its whole family
life is spent in this brief burst O
celestial splendor, which covers les.
than one-seventeenth of its entir,
span of existence. During the otheI
| q Ms ~ foe lac -
or five feet below the surface of tn,
ground, grubbing blindly for exist
ence among the roots of trees.
During sixteen long years to be :
crawling. ugly grug, grave-deep il
the dark earth, with nothing to looI
forward to except Il mere glimps,
ana momentary breath of paradise
and TO end existence just when i
seems to have become worth while
behold what the life of a cicada look!
like from human standpoint
There are at least twenty brood.
OF seNenteen-year cicada in tn,
United States, each brood having il.
own emergence year.
The damage that the cicadas do tC
vegetation is mainly concentrated up
on the twigs, in which the femal,
insect bores and saws holes in whicl
TO deposit her eggs. This operation
is so vividly pictured in a letter t,
me from Mr.. William Lair Hill, o
Oakland, Cal, that l quote it here
AT the time of one of the cycli
cal appearance of the cicada il
Southwestern Tennessee, when sud
denly an army numbering untolt
millions appeared, and the peculia
sound you describe filled the al
from early morning till far into tn
night-if not all highland one o
more branches of every tree wer,
pierced by the 'awr and the key
hole saw of the female insect eX
actly as YOU state, / was in that sec
ton of the country, and, becomini
! deeply interested in studying th,
strange insect, l observed its conduc
from the change from grub to flyin,
creature until the end of its activ,
period.
Il watched the actual making o
those perforations. They were al
! ways made on the upper side of tn,
twig, the process being precisely a
, described by you, and during tn,
operation the insect could not b,
frightened away.
"One perforation being completed
first bored in smooth with 'awl
!
ally roughed up with the two saws
the operator would move forward
nearly a quarter of an inch and re
peat the same operation till a row
of these holes of the perforations,
found at the extending along the
twig from an inch to two and a hal
inches long had been completed.
Cutting off a number of these
perforated twigs for examination
and splitting them along the line {
lettuce seed, only not quite so Ions
or so distinctly pointed at the ends
creamy white in color and semi
translucent. So in each of thes,
twigs there were deposited from 81.
to ten eggs. The grub, l take it
commenced its career in the per
forated twigs and passed thence
down to the ground to enter upon it
sixteen-year subterranean bottom o
each hole an egg-just one-abou
the size and shape of period"
CTV(TEI