THE EVENING HERALD, KLAMATH FALLS, OREGON
Friday, &'tomW 21, l!)2ft
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Page Eight
Legs
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0 Kfliy
lids, Crickets
Dioving
of a katv-
did dotting
I oca tion of
ear. . . Right,
a photograph cf
the ear anJ a
much enlarftd dia
gram of the organ.
k w w
Bv MARJORIE MacDILL
'HEN die great katydid chorus breaks loose in the tree-
top on the moonlight mghtt of August, presaging thereby,
according to the folklore of the country, a frost in six
eks. tew in the audience realize that the synchronism
! ; of the insect orchestra is maintained by a complicated
' little mechanism on the green fiddlers' fore limbs.
1 For science has established that katydids hear with their front legs.
) The whole question of how insects hear, see, smell and otherwise
j exercise their sensory functions has been the occasion of much learned
entomological wrangling. Some have even declared that they did not
hear at all. But an enterprising young entomologist at Iowa Slate
College, who has recently moved la the State .College of Agriculture
j ' of North Carolina Dr. B. B. Fulton by name decided to settle the
' question by actual experiment. ,
j .There are on the front pair of kg of certain insects of the grass-
' hopper type, organ similar in structure to those used for hearing in
higher animals. Only the species having stridulatory or singing organs
have also the tympani on the foremost pair of legs. Whether they
j actually serve this purpose or not. however, has been disputed vigor-
I . pusly. , .i , ,
; Close comparison of concerts participated in both by de-legged per-
i formers and those with the full complement of extremi-
.! ties was the method chosen by Dr. Fulton for "getting
I the dope" on the green winged violinists. .. SINGING ORG AM
The fact that certain species of
l singing Urthoptera (.the name given
. by-scientists to insects . of the grassr
I hopper type) synchronize their notes
seemed to me conclusive . evidence that
1 they could hear each other." Dr. Ful-
. ton explains. "Such a simultaneous
I sounding of note could hardly be a
matter of accident. Neither is it an
auditory illusion as some writers have
claimed. .. . " ,. . ;
i "While studying the songs of the tree
cricket and a couple of other singing
insects, I was impressed with the idea, that here was excellent material
, for testing the auditory powers of the tympani on the foremost legs.
' ' Accordingly I set about collecting males' of all such species as were
available in my. locality."
THE first demonstration was staged with 10 male katydids of a
; sort commonly found on the prairie;. ' They were placed in a
, cage where night after night they exhibited almost perfect syn
chronization. ,
"This insect." says Dr. Fulton, "starts singing in the afternoon and
as -evening approaches the number of singers increases. The song is
under ordinary conditions a series of 20 to 30 short metallic rasps at
the rate of four per second. Each series of notes lasts about five to
seven seconds and is followed by a period of rest of about five seconds.
vThe synchronization of my. 10 caged singers was practically per
fect ' The song of the group was continuous and as each individual
started its series of notes anew it wculd fall in with the general cadence.
It was only by detecting slight variations in the quality and volume of
I the chorus that one could be aware of the pauses in the individual songs.
"After observing tlte Jong of the whole group for two nights I re
moved four males to another cage at some distance from the first and
: cut off their front pair of leg; close to what corresponds to the thigh.
For the two following nights only one of the mutilated katydids was
' heard singing at one time.. On the third night two sang more or less
continuously. -" The notes, were not synchronized except as they hap
pened to sound together at times.
"The two males happened to have lightly diRerent normal rates
so that if they started their series of notes in unison they would usually
be sounding them alternately at the clo:c. I observed 36 con--'
secutive periods when both males were singing at once and of
i these there were only two when the notes did not interfere
' at some time, during the period.
! . "Following these observations I went back to the cage of
1 normal insects and listened carefully to four singers for 10 min-
' utes. " During this time th;re were only two short intervals
' during which a few notes were sounded nut of cadence as one
i of the singers began a series of notes. -
' "In order to be doubly sure lint my senses did not deceive
me I requested someone who had no knowledge of the experi
ment to listen for a few minutes at each cage to see if they
could detect any difference, in ihe songs. This observer noted
at once that the song was rhythmical and synchronized in the
first cage but not in the second." ' ,
and Grasshoppers
the Sm.em.e Insects
ist 'Below the JCnee
TYMPANUM OR EARDPUM
NERVE TO BRAIN
v
BRANCH NERVE TO StNSOfW Oil
SENSORY CELLS ARPANGED
IN A ROW.
EXPANDED PORTIONS OF
A'R TUf2S WHICH 6UPPLV
C-CY&EN TO HOOY FPOM
CENTRAL AIR CHAMBERS
rii-iUnriii-Jri aiasti . MIS in a in
gr a it hopper. . .
jhou'ing his ear
tearing orccji.
.'SUSPENDING-LIGAMEMT
NERVE FIBRE
"THROUGH CAVITY
FILLED WITH LIQUID
AUDITORY PEGS
STRETCHED
THE next batch of victims were sr.owy tree crickets, the
collective authors of that shrill melody of sound that seems
to come from nothing out of everywhere out-of-doors on
summer evenings when rite shr.dsv.s Lc7in to darken. This
music is probably the rr.o:i familiar ol all insect sounds but the
musicians themselves are little known to the public. -
They were divided in Iwa lot; li!:; their p;cdcccsjors and put
into separate rages. , -
"After waiting a few davs," Dr. Fullsn went on, to see
that both cages contained willing risers, 1 amputated the fore
limbs of one lot and removed their cng: from ihe vicinity ol
the other lot. The results wit c::5ntia!ly the same a with
the preceding experiment. When or.ly two of the mutilated
males were singing at once tlir cflcct was that of being synchron
ous at regular interval-; srpnrotrd by periods during which the
notes sounded alternately. Each cricket sanr; at its own in
dividual rate uninfluenced by tl:e sonr; of others in the lame
cage. When three or m?re mutilated males, were singing at
once an utter confusion of notes re:ultcd. ,
"The song of the normal tree crickets in the other cage pre
sented a striking contrast. Each individual scunded its notes in.
unison with other:, a if a single cricket ivcrc sinking."
The third insect used in the sen:s. a c'asshonper of the.
plains known as the Nebraska conchend, proved to be the most
remarkable synchronic of all. i
"Their song," says the entomc';-;is:, "ccnsisli cl raspi:
buzzing notes each lasting a little ever a '.e-?nd and separated
by about equal intervals of silence. 1 he length ol the notes
and their low frequency makes this species an easy enc to study.
"I placed my quarry ol four in individual ca.iej and sepa
rated them into two group: which v.tr: kq;t cut of hearing
. '"' ."- :- -
" 1. tr w i r r ' w s
conehead... , . . ; , M ilia A' "" '
LisemiIong- . i - iO" , ...
legged Tela- -. variations, K.ly, Kaly didn t.
uVet, he hears '. -f
With nit kp. Wj :4 .. .The katvd'ds. .: are the oris- rr
X iSiL evA' . ' locrati among all the nunieroui
..v.-jJC. .-jCTjWf -f this correlation is very evident, always.
-iSts- ff' fc-jfiPZ- IXk When neighboring crickets are synchron-
: Jtv t'&r V. '''r' Dr. Fulton ints out. they adiusl
' i awu-. tr :'S-. their individual rales to meet
jftf I " JX 'mn X the needs of the choru-.
LtP 1 y X V' ,' , though tills adjustment is
Cf -f 44cai'". ;' w: ' possible only to the extent ol
3 'i J Al t , ' a few notes per minute. I
1 W. I 'X' - . . 1 have Hound, he acJUrd. i
Jyr , ' tjiJ'vS. i. ( T -'. v ' cricket there is such a thing
aSt I-t i iV ' as a geographical variation
1 " '. f' "f-,t"r J 'n on- 1" general the
j Dr. B. B. Fullon. fji. $.''""?&:. ' "' 1" JL ' I frequency of notes at the
JtcJ entomologist. . . " " r Mj-i . I ' Sv I ame ,crnP"',,ure increases
amputated kat$- FN f-'JL''--:-- V one 'rom 10
iff didt legi. made . - . T ' v ' 'vl9V ' ' bave r, 'n'n
tliem deaf. V A,V ' "; v J -" M-- ' crickets from Ohio. Ari-
lirjutr , - torn and Oregon caged side
. 'a-2"""'" by side and it was interesting
The criclett, lil(C their grauhopper cousins. . . I fOl
fiddle with their vingt, hear with their front legt. 1 1 JPfA
Ws .
Singing RGAi -rr-f-,
yoiw. Ksuzsmsiis
insects Droduced can hardlv be a mailer of accident. Dr. sufficient adjust- D".,e w"n I B V .' V
II II k. B L, W
C
C.rauhappcrt ihcJ their il.ini foul" nWi before
then me groan up. . . Here are four cuif-ojf suits
vf ciirfer-totiti.
sideways, llie file grales on ihe ridse or scraer causing
a rasping sound, ami this is the way ihe katydid pioduce
its famous song. The lone and the volume are prubably
due largely, however, lu ihe thin mrmbranes in ihe base
of ihe vinn.
The inilcuinrnlt of ihe dilferetil families rff songilei
vary stimevlul in lite details but in uenei.il the noles pro
duced by the dilferent owner have a range out of all
proportion to the vanuliuiis in tlie musical au-
, paratus.
I he memlier of ihe numeroui katydid clan
srirnlivls I y ihe mellifluous name of I'leio-
phylla camrllilohi. helhri he is a gieat
l..'inic i.in or not drpendi on llie ienonal tasle
u f the critic, but of lilt
known l.ir and wide to llie AmeiKsn public
as the gie.itet of imect singers, is called by
from each other. - After
testing all of them for syn
chronism, which proved to
be perfect, the front legs were removed from two of them.
"On the second evening after the 'operation' both coneheads
were singing with conspicuous lack of co-ordination. For about
a minute at a time the notes of the two would sound alternately,
then gradually one song would catch up to the other so that
for another similar period the notes would sound simultaneously.
"At the same time the normal coneheads were keeping up
perfect synchronism. Sometime one note could be observed
lo start a fraction of a second ahead of the other but never
once did I hear them entirely separated."
a simultaneous sounding of notes as the uninjured
insects produced can hardly be a matter of accident. Dr.
rulton declares, and appears to be conclusive evidence that
ihey can hear, each other.
The structures in the tympanum on the leg, believed to be
actually responsible for hearing, resemble exceedingly minute
pegs. Each one is hollow and filled with a watery liquid and
has an axis-fiber or nerve-fiber running through it. The end
of the fiber nearest the body connect with the insect' central
r.ervous system. .
The structure of these organ led early investigators to be
lieve dial they were hearing organs, though actual demonstration
has been lacking until now.. Structure containing auditory
regs have been found in a number of 'other insects, including
the male mosquito.
Another interesting act about the music of the Orthoptera
:t the! the pitch and also the frequency of note vary directly
with the temperature just a the speed of a chemical reaction
does. Since the insect do not regulate their body temperature
like the warm-blcoded animals, their rate of metabolism is sub
ject to the whim of the weather. With insect like the nowy
tree cricket, which sing a continuou rhythmical series oi notes,
to hear them try
to synchronize.
Their natural
rate of song
were so different
that they
found it im
possible to make
sufficient adjustment."
The snowy tree
cricket. . liAc-
Bise sings with hit
minis, lists vilh
hit limbs.
aristocracy among the
IC'uii) rlglit, i'l'.S, NKA aiuicasiiie auil Htiincs WtrvkcJ
THE katy
dids, however, constitute the real
singer ot tne iix-ieggea insects. . , .
In Europe the true katydid, so common in America, is un
known, his family being limply styled the long-horned grass
hopper to distinguish them from their short-horned heavy bodied
brethren, who also are singer, but less notably so.
Their musical instruments are located on the overlapping bases
of the front wing. They are the special gift of Ihe malei.
the females having to content themselves with the primitive wing
structure common to the rest of the Orthoptera group.
The fore part of the right wing of the favored sex con:i(s
of a thin crisp membrane with a slid ridge on ihe basal ant ic.
On the left wing one of the veins 'i thickened into a close srrirs
of ridges on the under tide, which convert it into a veritable file.
The wings of katydids are always folded with the If 1 1 over
lapping the right in such a position that the file of ihe lormn
lies above the ridge of the latter. When the wings arc mouj
fame theie is no question.
( erlainly nothing could
Ih- plainer than his voci
fnous "Kalydid" with
its endle repeiiiiins and
Kaly she did."
HOUGH the audience of the katydij lis a v.ide range,
few claim the privilege of personal acquaintance. Irom
the fact lh.it he has selected (or Im s.v.e the lalleit tree
tips ai. cJ seldom descends from his thoien oichf.tra chile.
Country-raised beys and girls and hard -hunti'ig fi"ld en
torr.olcgi'ti know liim. but not ni my more. In color he 14 plain
rreen wiih a dirk hruvn lii.myle on the luck catering llie
ilrid.il.itMig .nea cl ihe wirp. I In body i fully one and thiee
i;u.Mters iixhea li nn while his h'nn hair-like anlerinae measure
well o;er lv.o and a h.ill inches.
The rear edgis of llie leal ;ieen wiiijis are evenly lounded
with 1 1 , r sides plumped out as il to roter a corpulent rotund
body. I hit is a f.'.lse alarm, however, for the i.pace lielween
leni is mostly empty and prnliahly lnrnis a r--, ,iuncc dumber
to give tune and volume In his muMCrl erlonii.ince..
1 ie has a row of prominent wartcoat buttons down his front,
nr rather his undrrntalh. that ihythmUuily hr.ive and sink with
e-ch breath.
Another insert sinrer much in the public eye is the black
field cricket, a friendly soul of gaiden and d mryard, not averse
lo taking rcfuvre in the hnure ilsrlf rn cool mil'itmi evenings. His
I urrp:.in cousin n ihe famous cricket on the he-rth of llieken'
Mory. I he ancient Greeks and H'vT.ani c.ille j him Gryllui, a
l.ame which he heirs lo this day.
I lis muMc.il organs are much like the k itydidi'. I nt, unlike
the latter, he has them c,iuy developed
nn each wing, so llut he can apparently
pl.iy with either vvinit uppermost, though
in actual puclire 4noil crickets consis
tently wear the liiihl wing uppermost, just
the reverse of ihe katydid custom.
'I he snowy Irre cricket that played a
prominent role in Dr. Fulton' concerts
is really green, but of such a pale shade
that he looks while nt night. In the
g;een nut of-doors orchestra on warm sum
mer nislils. a careful listener, may dis
tiniMiiih a short brat repeated a hundred
or m ire limes a minute. This strenuous
perfoiman.ee is produced by this pale little
fhosl of an insect no more than hall an
inch long. Ihe singer raise his wings
vertically above the back
and vibrates them sideway
so rapidly that they are
momentarily blurrrd with
each note. He repeats regu
larly and monotonously all
night along, and by some
people is cursed ns a pest,
When he first begin
singing in July there are
about 125 beat per minute,
but later on hot nights the
rate will go- at high as
' 200. As fall come on it
drcrcares to around 100 and finally as the nights grow cold, the
note end in hoarse bleat repealed slowly and tremulously
thpugh dill rhythmically as if the sintrer were numb with cold
nr pain. With the cr.ming of the first frosts ihey die. away
altogether. , ...
Il is probable that further experiments will be made lo learn
. bout the strangely placed and curiously constructed ear that
the katydids and certain of their relatives are now known to have.
Recently, it has been shown that various moths and certain
lyprs of butterflies appear to perceive sounds, and caterpillar, of .
at leist (wo sperirs have been lound lo react to sound '
None of the in-ecls used in Dr. Fulton's c::prrirr.fnls seemed
rjrcally disturbed by the lots of their front legr,ji:(ir those oper
ated upon lived as long as those whore legs were kept intact, a
condiiinn which aitpies in favor of llu olt-rcpratcrl statement
llut inti'Cti are not very sensitive to pain. And besides, grass
li.j pcrs, when tr. pped, uflrn kick their lejj oil,1 - . '