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| EMBRYOLOGICAL STUDIES ON HEMIPTERA
7 1. Development and Morphology of the Mouth Parts

JOHN PHILO GILBERT, A. B., 1905

THESIS

For the Degree of Master of Arts
in Entomology

GRADUATE SCHOOL
OF THE

UNIVERSITY OF ILLINOIS

DNIVERSEEY OF TLEINOIS

f
]

ne MU) 2 aes ar a os0)o 17)

THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY

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IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE

i NO rece ee ck eoct eave co nich atnvonirnatinmnnninntrninnsnnlnd

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“Wy

FIEAD) ORM DEPARTMENT: OF, COOL ORY ole ccasssmsnoninmisininonnineunannnnaminnnaninninns

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un

EMBRYOLOGICAL STUDIES ON HEMIPTERA.

eine
faivonent and Morphology of the Mouth=Parts.

}

by
John Philo Gilbert.

Contents.

ve

Introduction eee ee ee ee ea
L es
S|

Materials ------ aoe nenee Dates
4 oe

Me
a

_ Labrum and Clypeus

Intercalary Segment

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in 2013

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— | INTRODUCTION.

|

Bee \" ‘
The morphology of the mouth-parts of Hemiptera has long
a subject of dispute among zoologists. Nearly all the in-

igators who have studied the morphology of the Hemipterous
al

n-parts have neglected to study the development of these or-
Organs 80 highly specialized as these, however, cannot be

Po

stood unless studied in the egg and nymph as well as in the

pe “
This thesis was undertaken in the hope that embryology

ure and morphology of the hemipteran mouth-parts. The common

ow some light on disputed points relating to the struct-

>
my, eae :
| bug, Anasa tristis, was selected for study because this

tive species ané because the material is

_ The present studies were made under the supervision of Dr.

_ ok
J. W. Folsom to whom I am most grateful for encouragement and

i.

, are Ban iyeree t& & aor heey ne 20 ints £
i me Pie Vrinet ~~ .adetuutves, sewn “hme tt dl
seetetctme? a8. To “adloso vow oft SoePiaie aaa

san 4000s to nese ih ol thug es 0a aaa

So 70qhed.: NeVOWNE.. ent? 47 ongk es tong’: 2X (Oe he ae 2

a | AM.
Sd? «ium (ae ce Arner fre wot Of) ate ake gel

Wad loywine Jad? o¢ t0% 1 wee ee 4

’ oy

Seiceie of) ‘07 abides aiatod Segane tS, 40 Same
an
nemo s (AtT |p aktcc-enm mane glate. ott ee

Hit) Sevects vhite Sut be ton 4m eve , +) Ee

Sf ftelecdag ptr enracsd Bin sain tag

Lal Yo eotetrtaqa off ately ob ee unthe ree

ere tt: sannr ~ spe WY Ia Telatia Joo

MATERIALS.

n Anasa tristis.

this work were obtained in two ways: first, by

4 — for

ecting from the food plants; second, by keeping pairs of

By searching the lower

Its under observation in captivity.
Peaadacor squash and pumpkin leaves, large numbers of eggs were
sity obtained. The exact age of these eggs, however, was not

(Females cease oviposition when slightly jarred or when

the a strikes them suddenly)y To avoid uncertainty as to
ei i

ses pumpkin leaves every six hours. In forty-eight hours
ies cee had appeared, so about seventy-five pairs of the in-
[8 were placed on a small squash vine in the garden. <A box
open at the bottom and covered above with wire screen served to
keep the insects in captivity. In an hour, one female was de-
ing eggs and during six hours, fifteen clusters were laid
bhe leaves. The twenty-five pairs left in the bell-jar for
several days deposited but few eggs. Evidently the insects pre-

the plant surrounded by the box. The box, however, pre-

vented the observation of egg-laying on the under side of the

é
7
7

ce he

re havens sich ie

oor st

of} hee “ia “a
At mG “oa 1.4 wg

apy oy
n

a P<
re

-_tr ‘istis is most active on sunny days and rests near the

ar the plant, partially sheltered by leaves and clods. The .
oe the plant too much, however, and the insects col-
ected on the wire screen instead of about the plant. A bag made
1osquito netting and left open at both ends met all difficul-
ties admirably. By slipping this over a running vine and tying

» ends loosely, the insects were put under nearly natural con-
‘This bag could be raised without disturbing oviposition,
-_ one could readily make observations and remove clusters of

| eees. All eggs were rejected unless I kmew their age to within

| fifteen minutes. By continuing these observations for seven weeks
| T obtainea @ large number of eges of known age. The leaves bear-=
| an ng these eges were kept nites a bell-jar to prevent excessive

ing. Eggs adhere so firmly to the leaves that they are not
“aisio bape ot by the operations of killing and fixing. From five to

mate--acetic acid killing fluid. This consisted of a sat-
[aratea solution of mercuric chloride in 35 per cent, alcohol with
| 2 per cent of glacial acetic acid. Eggs were left in the killing
fluid for two hours, and then transferred to 60 per cent, alcohol
for six hours. They were then left in 80 per cent.alcohol for
six hours and finally preserved in 95 per cent.alcohol. Several
ser ‘ies, complete from deposition to hatching, were obtained, the
intervais between successive stages being never greater than two
hours.
a Material can be collected from the middle of June unti1
late Fall. The first squash bugs appeared on the vines June 15

on ee bugs were numerous June 21. Eggs were found June 18 and

tee Pee Ze
9 y , | @
ee es {se a meee! ei A ene ok ane = as ; r

: os. ,
were fairly abundant June 25. They hatch in from nine to twelve

"

‘I found no exception to this rule, though Chittenden ('99)
“Ta , 3

Miices the period at from eight to thirteen days. Clusters of
rs were on the vines August 15, and oviposition undoubtedly

ontinues much later than that date. On November 4, after the

&

nes were dead, A. tristis was found in very large numbers on

rf:
Vit

gether with Diabrotica vittata, were literally eating to the

=
4

center of the fruit. At this time no eggs were found and there

| were no nymphs of the first and second stages, though all other

*

1. pout five days. Chittenden ('99) places this period at three

Length of stages.
E emer 8k 822 Lt vehs--2 9 to 12 days.

+ Instar wooee~---------=----- 4 to 6 days.
Bea ae ee Se -6 to §& days.
he: | ee 6 to 8 days.

25 to 34 days. |

my * The term "instar," suggested by Fischer and recommended by

N

Sharp, is here adopted for the sake of convenience.

ae SL han

+ = - = = nH
; | :
favk
2) be 4 t
4 Dee uf '

LO”) aia >
orga is4 ha Pea Syke mc?

4

bert both adtiiwcgtye. Gite (,éf twagwA

SSS ‘gepyer nO’ cated tet? Aedt “etalk

Ie

7

oy ei re om)

a oe, Toda lS ws Sednmagye ™ indent? pee

, - 7 f

wnt segnae Yo evar ad? sy bs tyoba 6 :

‘~ ,
4a

Pe. > «& i) 62 he

a my

“ , November 16 revealed no third instar. No dead

eee

{7 01k mans. The yolk could then be removed easily. At the age of

ae . 5
| color, which deepens and extends as development proceeds. Such
aie

- can be isolated without artificial staining, ees

i
4 ar

| microtome. Sections of earlier stages were cut to a thickness of
104, while those of nymphs and adults were in most cases as thick.
as 16 2/3.4/or 207% Sections were affixed to the slide with

yer's albumen fixative, and then stained with Grenacher's borax-

Plecatne, orange G, Delafield's 2 ac ania or safranin. Carmine

ean toto preparations. Aniline green was found to be an ex=
lent stain for chitin. |
Dissections were made in glycerine. Temporary preparations
‘were left in glycerine, and permanent mounts were made in Canada.

o- Objects were examined both by transmitted and by re-=

-.. collected late in the season when they had assembled in large
i)
| umber s on such fruit as remained in the patch. These insects

=" killed and then preserved in 95 percent. alcohol.

Outlines and proportions for all the drawings were obtained

oy the use of the Abbe’ camera lucida.
THE EGG.

When deposited, eggs may be light in color but are usually
es

| dark red or brown. Light colored eggs usually, but not always,
| turn darker on exposure to light.
1 a
|

f
ri
ae |

The ege is roughly triangular in cross section, with the

2 ea Side flattened somewhat at the place of attachment to the

. tentay in different eggs. Before oviposition the dorsal sure

| this fills out until the egg is nearly circular, in all instances
in which it is not pressed firmly ageinst the leaf at oviposition.

Maen ees rest lightly on the tips of leaf-hairs, as they fre=

) >

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‘ Nee 2 Wr 4 39) oe

i Be Bale they eubeteea arctic). 9 ME aoe ota
ebsiee® ct. what ew qEVON ae | bae.. et
. “et Ye hist tis tombs Gl aired teinkbad, ain |

-

“foun! els *thdl ges to, ror oo! otter ceden ft oni
Hijet Som etek) oh obTTiO ude bevensx tag |
. gn ial ni ie fopemme bor euhl neck rOuaos aff ef 0 he
, afore eeGi, «FR oct? x? beriaberi ap harry |
stodesia sintsws. 1C oc bov 4ne te Ree

Seortarty arty eyhieexs end ite “o> pnolteqeay am

.a0toul Eterna

. Tei | he) Saf pt Pena | ni mt “iy ve
seemeie Jom Yd .vifewan want oreo

Of? frie atior “enan> nr) wine's) (a
he) 6g sna tes Tee ioe lle
Rep ade!) ed? *9btso* t ~rots 27a Pobte Bee
O1.f gies Gutevniay par x .. gion tanebyeeee

jo! ~-ary ar sory ty) aoe! cm A. Sn eee Sal

o\

~~ ina at ag °¢ ates thaagt at vio rent (Me “vou WRht 7 |

Qtuntrace Ykoco! arab. ge Vid , evensob.ceeelaene lek
Strradenl (fn of , Salmo hh eho eheadt og § uli
Ae a ieorive #4, Weel odd Tan hee eterets binionerteey

wort grat opie tee gh? ant a

te Ra ae os Os wa oe 7

1) Vane ea? eo le

Bent of the plates of the ovipositor, the female presses the
| egg firmly against the leaf surface. When thus attached there is
a

_—. less flattening of the dorsal surface of the egg. A small
| amount of a mucilaginous secretion fastens the egg to the leaf.

1

‘The le ie-haire frequently adhere to this substance, and some wri-

Near the anterior pole of the egg is a lid, which is re~

a when the nymph emerges. The lid, ventral in position, is

| delimited by a light colored border, even at the time of ovipo-

“| sition. The chorion is marked off into very regular hexagonal

a; Just beneath the chorion is the delicate vitelline mem-
| rane.

From 9 A.M. to 1 P.M. I found to be the usual time for

| oviposition and eggs are seldom laid at any other time. The fe-
| male usually selects an angle between the veins on the under side
: the leaf, turns her head toward the edge of the leaf, and

| | places her eggs in rows, in a rather campact mass. The egg is

i]
a

1 placed with the ventral surface downward, when leaves are in
peer normal position. Nymphs emerge mes first, after loosening
. the lid and pushing it off.

rt. .

iy All the eggs of a cluster have the same hatching period,
with put little variation. It takes the female from one to two

| appearance of the first and the last nymphs from the same cluster
is seldom greater than three hours. The blastoderm becomes evie
| dent when the egg is about twelve hours old, and segmentation is

in process at thirty hours (Plate I, Figure 1). The primitive

“ban

|
ad is of the invaginated type, occupying a superficial position |
near the ventral surface of the egg. The major portion of the
isi always remains near the ventral surface, but the posterior

a

| segments and the antennae extend around beyond their respective

|
v4
|

/

poles of the egg. The protocerebrum and deutocerebrum can be

“a

|
t
|
}
i
distinguished easily from other segments when the eges are thirty
| hour old, but the remaining segments are very similar to each

other. (Plate I, Figures 1 and 2). The germ band consists of

| twenty segments, six of which are cephalic, three thoracic, and

twenty-one hours as a pair of large lobes, and the deutocerebrum,
bearing the antennae, appears at about the same time. The tho-

ue i *

| racic segments develop faster than the remaining ones (Plate I,

ny

Oo

eleven abdominal. The protocerebrum appears at approximately
| ‘Figur ures 1 and 2th.). There is a rather gradual diminution in

; ze from the metathoracic segment (Plate I, Figure 1, th. 3)

| forward to the tritocerebral segment (Plate I, Figure 1, tr.).

| Within a few hours after the appearance of the protocerebrum the

| fundaments of appendages appear and the difference between the

| seenents becomes more apparent. The labrum appears also at this

iF time, or when the egs igs about forty hours old. When it is fifty

| hours old, the inequality of development in different regions
— very prominently.

Rudimentary abdominal appendages first appear when the germ

eh ae
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a about th irty-rive hour s ord! aetteen hours later these 3

a sepments Peitic 2; i oN ab.,ap.). They are less
tinct on the ninth and tenth segments, and are difficult to
detect, although present, on the last segment. These rudimentary

| appendages: Decome more prominent on all the segments and reach
[their maximum development when the egg is about seventy hours old
(Plate 2, Figure 4, ab.,ap.). They are then slowly resorbed,

Be persist, however, until revolution occurs, when they disappear

When about seventy-five hours old, the fundaments of the

| compound eyes appear at the outer border of each protocerebral
“lobe, and at ninety hours they become conspicuous.

Previous to its peietutien tile germ band lies near the ven-
|trar surface of the ege with the head at the posterior pole of
tne egg and the appendages pointing toward the dorsal surface

_ 3, powers}: Just before revolution, the appendages

—.
Bex / 5 mth Ales : :
revolution the legs, which now point toward the median ventral

line, elongate, cross the median line and interdigitate. The ab-

minal p portion of the germ band now grows up the sides of the

i

es and closes over at the median dorsal line of the egg, thus

< enclosing the yolk mass within the abdominal walls. The organs

OO OU EE ™ OP el”—“—S a es

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Bio Ghd Ytewou Mite gl apn edi oat Sota ia
poet tos ei ued? din: Van? «hg Be LR ‘ Y *

Hang q@uith ess wir Pec nD soicy love t Ses

we. to aiheine oat Of awd ith eee 4
Lemiaiodtiwy Apa, Uwe ooh ie (ete Adee ~aninga ys
am gust uc veo ais? AM fers h ‘

See ety Sen HO Gard) oven ett ackon tc pert eee:
Re oq. Wbretady ef) to Aneri.ahT 4d be ol
C007 Swe Lia twh or wot pthrattg « eis beat
nomehoidGa- Had jedi ves. ery tet Sept A

pe aeey selieom end! binwo! 7): - A Na sisal dgag hat
ieioep Seo €Lo. eiwod.d. ~brakt ono Coed cme «dal

; : at le’. 3a
Bi64 ~¢t ethey eay tices. Pia? ove rae oye

: . yietgimedivoten teat ot?» {9% andy ae
wel oye auplare- S yp ra ee 00 eee to * ote F) as,
mtGessaes7 20° todd wie whrogeertbo atoelt abe

‘atte mos yor «(OP oniptth RiadeteW (OR) See
eriae® epilar eto. Bw: On BG Ohi ate ie «omen
e0m eT alg lipiiow 6b Bem out FOR tie ott) Ban ee 7
“1? le etBto of2 of ages bt eft] esr et te
Ma gag 2 no A erie Abin Re aes aie

Spy to et oak lam Conte ag) tiie
- « 4 ea ae

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a2 Ne

a .

e

5 oe t
a A } aM a ie’ 1! ;
Boe RIE fy 3 ae
| in the aboye described position until emergence. The pro-=

of revolution is a very rapid one, and requires but two or
(Saal ui ,. >
Ne

hours for its completion. The three figures referred to

ANTENNAE.

he » The antennae are the first appendages to appear, and they

as... ; :
risible when the egg is twenty-five hours old. The antennal |

a 4" : A
| bases of the antennae. The fundaments show a slight constriction

| when thirty-one hours old (Plate 1, Figure 2.). Growth occurs

ae ey, i. t s s 2
throughout the entire appendages, but it is most rapid, however,

in the apical region, The segmentation of the antenna begins at

ase and proceeds toward the apex, until at length the four

‘becomes larger than the remaining three segments. Previous

wv

Pa
revolution, the antennae point forward with tips curving in-
a

Ta

ee

ward so as to meet in front of the head. After revolution they
point caudad and are paramedian in position, one on each side of
_

he labium. During the period when the egg is from seventy to

sty hours old the forward migration of the antennae occurs.
4y are post-oral in origin, but this forward movement, together

| with a backward migration of the labrum and the oral region,

wed rather sparsely with stout setae. The fourth segment has,
In addition, numerous fine setae. The segments are sub“Pliptical
nearly uniform in size when the insect emerges. During the
nymphel stages, however, the second and third antenna} segments

Ae

be some more slender. The joint between the third and fourth seg-

he sub-segment is not found in any stage of the nymph, but the

| mation of this sub-segment. The structure is apparently of great

rvice in giving freedom of motion to the outer, or tactile,

a —_

segnent. Such freedom of motion is possible in the nymph without

Sa

i — since the antennae are not heavily chitinized,

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2
LABRUM AND CLYPRUS.

tennae, but protrudes forward between their ? ses ivring the early

stages of its development. (Plate 2, Figures 3} and & ir.). When
about fifty-five hours old the anterior border of the labrum is

almost a straight line, with a slight median indentation (Plate

| m, , Figure 5 oF ). This indentation Wey. heed led to the erroneous

h 4

he's y sk. }

ie bs aoe

eae i +i 2. Ne ; = :
asion of some authors that the labrum is a paired organ.

ful examination, however, proves that the labrum is not a
ey

ired organ, but a single median evagination, as foind by various

other authors. The labrum (Plate 2, Figures 3 and 4, lr.), cor-
/g cs
resp ponds, in every important detail, with the labrum of the man=

oo type- compare my figures with those of Calopteryx, Brandt,
(Plate 1, Figure 11, v)., Forficula, Heymous, (Plate 1, Figure 9,
cs Ofeantnas, Ayers (Plate 18, Figure 15). When it is
seventy-five hours old, the labrum begins a rapid elongation; and,
lat the same time, it begins the migration which eventually leaves
lit situated between the bases of the antennae and somewhat pos=

| them. The migration is accompanied by a change in die

|rectio so that the organ ae caudad.

&

@

The first evidence of oral invagination appears wae when
|migration begins. A distinct stomodaeum is formed by the time
“revolution oceurs, and the cells surrounding this opening are
iclosely connected with the ventral surface of the labrum. At the
ibase of the labral fundament, an enlargement appears which from
|its ettuncton may be termed the epipharynx. The stomodaeum
lengthens and develops until it extends far back through the
sao to the stomach. Just after revolution the clypeus appears
an enl aves thickened area at the base of the labrum (Plate 4,
fre 2, cl.). This area is separated from the labrum by a dis-~
Bi - sove within twelve hours after revolution. While this
roove is forming, the sides of the clypeus grow forward and side-
ward for some distance and aaee form an elongate, rather narrow
piece on each side of the base of the labrum. These pieces oc-

| coupy the same relative positions in the adult insect as the areas

ee the Cicada head which Smith ('92), Marlatt (193), and Meek

a Ria eee

4 208 mE eR) © a ; ibs we An a
Deans tee ef Tee oT oF cotter haa tae hdeeue 0
ered), (55° ies € veupne (x Gt ft) pire’ et or
Anhe wi¥ tn Rete ee ooh _ Sha tOR. Cant oom, ¥F ah
oer. Soowten A Te rae? Meike eT Cea

: yr ‘pine ,.4 abate: TO he RET Ne, viz ‘ ne
be sf of wd Car dre fe vs tek T ) pepe Ph
. as, (col vegrola Pigest = mart ft od Wee ent ae |
‘ ®ovass YL inuitivies fala oot oeniot oe gas ths
ae. &) “20q Coxtceee Orin oertedo os ett Jo angel eg

% aif ri Sores 8 ud Riek; PetAnagad eh te > AeaSeee oNt

7 wake jot: @ Seite ‘cM a8
: y soca fant Be Style itr : of SRY 6 Bair eZ J lard Ta "
ig Sati satel Fenri t scrmatighde™ Mor lde eee ALM

atm gnte@oa siftd sp ilboo. care wethio ee brie me
reas. 84 ceva? YO cote Enatoet as? he

SOst «ole esas rete kira derontonty B%

WUGADNgET, FT ont title eet Bere

af Moe: Futd “wt ehoasan FL Diva

ane er t arin nee

‘a
—@/s “f eondel o@f woe™ totnoaeen hee rls
| s ‘ rT ’ - : ~~ 3 Poy ye ‘
| ae elim onl dere > nen We ee -
ad

Piatalt) wviel oY Yo bax ont &

eorcr inn Dowel wot amy ip 1d to mehhec tae,
qa~rayy vette ieee a. ato elt! ie sort eg
<0 choe lg peer! .ceOAt atl Bor ebb det Koren
’ eee @ 4 ct Tonal ¢ indy abt ae Hogt ibang, Beh

y = . ein
: mye (ae i M > We
a aw Dh *) St se: ao + pm

"eG

0 ), term the ' "mandibular selerite.” Any one investigating A.
ig from the purely anatomical standpoint, as these three in-
peters have done with Cicada, might saaily fall into the er-
oe ne these areas "mandibular sclerites." The more

trus stwor thy embryological studies however, show the true origin
‘to. be. from the cliypeus. This fact preecrs the possibility that
“the "nandibuter sclerite” of Cicada may not have its origin in
mandibular segment. At any rate, it is certain that there is
no- ‘mandibular sclerite” in A. tristis. The labrum, before emer=

i
| gence, -becomes transversely and deeply grooved on the dorsal sure

nent of the labium. Into this depression the labrum fits very
losely, when in its normal position. On its ventral surface,
(the labrum is deeply grooved, to admit the mandibular and maxil-

as
na

ey setae. At the base of the labrum this groove is completely
sted by heavily chitinized walls which hold the setae securely

ye

Within the base of the groove (Plate S, Figure 1), Ir.). The

ro ve gradually becomes shallow until at the tip of the labrum
a j
there is only a shallow furrow for the setae (Plate 5, Figure/2,

ae :). For about onei half the distance from base to tip of the
labrum, the setae lie entirely within the labral groove (Plate 5,
el3, li.gr.). At the middle of the labrum, the labium and

ex

he labrum share about equally in surrounding the setae, while
| near the tip of the labrum the setae lie almost entirely within

he labial groove. It is easily to be seen that the labrum acts

| mechanically in bending the setae into position. It thus plays a

—>} SS SSS a e_3

€
=

44 i: -

, a eae? bg og gu taine and suppertine whe setae in hear

MANDIBLES.

rt:
a

eer fundaments of the mandibles appear when the egg is

we conspicuous (Plate 2, Figures 3 and 5, md.). Until the
er * ._tristis is Bice fifty hours old, the germ band resem-
‘that of Orthoptera and Odonata so closely that it would be

| ssible to rg whether the fundaments of the mouth sadhs il
a... the suctorial or the mandibulate type. This Vay't
in connection with the other well known evidence, may be taken to
indicate iat te. suctorial type originated from a mandibulate

he The mandibular fundaments, like those of the maxillae and
the labium, are evaginations of the germ band. During revolution,
ventral portion of the germ band where the mouth parts are
ached grows rapidly anterior to the mandibular fundaments and

lis partially resorbed posterior to the labial fundaments, Wot all

of the germ band takes part in this extra development, so that the

Isaéeoe tehlaotea? of) | hip Spe ES dering! af ele ‘9
ne gedm@ln al oi tas (at ¢ pninie pho 208 4

(eds. .f erp ,f etady) Sees. mies By

Mot weil of of hh) govig, Peden 3

“sae Yuta, srt! . Pe rr" aries fat sai od —

Sas to aligenpae Yatito Gil) Leote oe hee Pet Bde

ier tees “teteqee .o to Logis tate i Tei a
. eT haat BAK

ef ane ef) celta sues, a8 DAE ee eds :
Tete T9fAL Sted dvastii. io mag dee: Oe ea av *: %
|) ee ee TUF eke be —@ hun = sonra Py, 9 SHOWN Gara a?
eee, load aug, ed! )Afo smo YRit)) Tei ee |
o¢ Etuow tf Jans <lend’a om ofenobhO fs teres
[hiv oie: Gado. 18! Yo udiecsbao’t ad) “ae an
: ‘ n BJD sagy?. ete tedtbrhizw 44 1D CAC OLS
bf ces ol the ,damenivn fro Liu® Selo: eae
Matvlioww @ avi hedsei nn! iowart fala me, wthon .

iis ABLLixXes Os 3° *6083 ori! ¢® iva irs “'e Conf kee

wer.itul ove ar tinh . red vies out J ba wed dt aera,
Te 8° MiSom ete we fepd mies) ads to ol ta

Dre «luemabat® <#¢le (peta oe 6d 4d ois CLE hike, ‘

fSe tet -aditemabn? Silla 942 ot takveteug Sota
hn Fk
Pees? tech on nego geve. wtp l dele ‘he plet

/ ‘ Yee

s ? “a Poy ate

4 jo ct iol dine Tee | . up

parts, which are at first at right angles to the germ band,

ome ‘parallel to it. When revolution is completed the bases of

tion of the mandible, so that it curves ventrad, leaving little or
no direct connection with the top of the head. The tips of the
ndibles retain their position, but the bases rapidly retreat
thin the head, growing rather close to the side walls of the

The bases of the mandibles soon lose their connection with

as growth proceeds until the bases are distinctly coiled.
py the time the egg is about one-hundred-forty hours old the man-=
|aiples extend to the posterior part of the head. Yet this back-
ward growth does not cease then, but continues until the base of
‘the manaine reaches the metathorax (Plate 5, Figure 14, md.).
a the base of the organ remains coiled up until emergence.
waite the mandible is elongating, a muscular sheath forms around
“it near the tip, (Plate 5, Figure 15, mu). The muscular fibres
| nnected with this sheath are attached to the sides and top of

e head. The mandibles first enter the labral groove during the

ip rocess of emergence. To do this, they slip down through the mus-

“i

Baar sheath, uncoil, leave the thorax completely, and move for-

| bd until the knob-like structure at the base of the organ reach-
| the sheath (Plate 6, Figure 16, k.). This change of position
is a very rapid one ena is certainly ow about by the move-
[ment of the muscles when the insect struggles out of the shell.

A very large number of specimens just ready to emerge were dis=

| sected and in these the mandibular setae were always coiled in the

. Large numbe: i‘ of nymphs were dissected just after emerg-
--gome even before the legs were entirely unfolded, but the
e had moved down into the labral and labial grooves and their
3 were always forward within the head, or at the muscular
If a nymph just eae, to emerge is dissected, the setae
ay slipped back and forth through this sheath, by a
ee ee rastion. Figure 15, Plate 5, and Figure 16,

i

i a a6. is from a specimen just ready to emerge and Figure 16

is from a nymph barely out of the shell. The position of the

a

a tt

base of the mandible relative to the sheath, shows how far the
ae

setae migrate in the brief period of a few minutes. Certainly

cas: down the entire length of the labium immediately af-

e} mens the shell. This description of the mandibular setae

i. lary setae, fa the pendibles and maxillae act together in
‘+. these changes and movements.

airs Immediately after revolution, each mandibular fundament

| ts avery shallow aes extending along the inner surface
BF ane fundament for the entire length of the organ. This groove
ye pens and its borders close over and unite. This process leaves
a hollow tube of ectodermal celis entirely inclosed within the
- These cells secrete the chitinous substance which
the mandibular setae. Figure 17, Plate 6, although repre-

ee the maxillary fundament, will illustrate equally well the

4 “a

ace ee 1 cavity which is closed, however, at the base and at the
,

tip . of the “organ

= a

mkiea, put entirely bone ee the seta. The seta ruptures

In the nymph and the adult, the brown chitinous mandibles
situated laterad of the maxillae and are held closely to the
1 ce by a neatly fitting articulation (Plate 7, Figure 19, md.
yi This joint permits of a free lengthwise movement of the
es, independently of the maxillae, but does not permit,
yer, any lateral movement . An examination of these joints

2 2, Figure 19) will make clear the cause of the difficulty
a in an ic a to separate the setae. The labral

rs

sroove holds the setae firmly where they leave the head, and the
tube formed by the labrum and the labium supports them and helps
to prevent the separation of the long slender setae. The mandi-
bles are uniform in structure throughout most of their length,

put the tip presents several distinct barbs (Plate 7, Figure 20)

| which doubtless serve to hold the mandibles in the tissues of the

§

1 ae cit
f Pyiiathcs ew oF Es elikean ©, 1M +e ter Dee =

~

bod

“a |

: ve
wi’ tiie Bovedman 6 ike Cr #%n beteo ‘ied né

. y 7"
of? » wile faite! = Jee Re a ae? free 4 em aT Ae
eeSey chagitiiis eft cAleveT gi Ji ROB: sill is

"© want fooereavt a rae {ism wetln aia Se

Settiuct #76e e@fT rior we! colnetoné cteetins suid

wit ohm Tate . capris Soesnl oe aliay PY
Ro méknibg fated Byatasae os" ae wengqau be lol
‘ fe
oer ge EXveicqant (fF owt ,*% etal") salbfleee pote.
ny a? _ .
=2eml le & or ve tay od a] sf) io nos P*i5 " . ae hye a y a

4 TEE NS) Sarak ita oil
BOfeviterm awvori hide: se 1! oofy 5s Leha at, Te sett oa

ane. 0! wlenoio ? (ne «-y ' Laenees wy 3S a
4 «Be orf eno “7 A, . ry) w« *hittvh tee “et sts ee

of

Kh ray ; Sg4ure@ 17 a «5 brivee GY

eT Cy eG (2 -laet st Vie
} *y af 7. Wh - ae * ’ ) ; J Pinks] tie ib? y
a7 * ‘ 4, 0 ean si vy; r Ney ¥ivir? i De if
) pre ifwi? 7% nm fils [ aft vA no-annt ott Oe
42 > 4 * ae ; Lad 3 ah in totre f The nas Le ee aS
tigehl S20 te ice tude auiksosie
= 7
fs Md ”
> su 8 Zz c :

vial toettehe Caw eo Leal
‘. ae 4060 @20 06a eek ae i to «tf Dhog char i

om

vi
; :
ae ;
f ; ‘]
oF - a
aa : tf ¥)

Just above these barbs there is a piece projecting

| the tideues! Just above this plate, the ventral edge is

a a short distance (Plate 7, Figure 20, md.se.).

re
‘ave
Uy
“<

a

a: &

oer the fluids to and from the maxillary tubes.

MAXILLAE.

the setae by invagination along the entire fundament,

1 eé age is joined to the maxilla of the same side, but is

The

ee. and near the tip, has grooves running from the

Exe

it ie

The maxillae retreat into the head, coil up in the thorax

andibles. There are important differences, however, which de=

v7
vy

a # ~~ ; 7 - - |
Ty arhroSl bap ade a a Se
g q y

> =~

scthaibe

ook agidtol<4 «At , ng? 4 ¥ “pid uF ge r

a

oy FS -oRigse’ >? 2}

wey:
“"— ; a = : a, ‘pew ; re > 56h

| S; . ed ; “9° why | owarrek ange

®
. * “ Pale
¢ r
)
) 1
4 i i “An of
_ ’ L ’ v2?
i. ‘
4 . t

oe ne «fiserr™ x uf noe

- ; | , ebm Avital * bet ee Mae
ae

> a

a 7 ‘ori Se ae

3 ‘ ‘
| ae. |
rye special attention.

i ™ maxillae are situated posterior to the mandibles, and
like the latter, are attached to the walls of the head by means

of muscles. A distinct maxillary palpus appears laterally at

y
the base of the maxillary fundament when the egg is seventy-five
in i

| “aa .

[hours old, and this palpus is prominent when revolution occurs

| (Plate 7, Figure 21, mx.p.). The palpus enters the head with the
| maxillary fundament. When the egg is one-hundred-and-forty hours
—

| old, this palpus is still found near the tip of the maxillary

a. but has undergone considerable modification (Plate 6,
Rigure 17, mx.p.). Modification continues until the maxillary
| palpi form pointed chitinous pieces which fit closely into a V

ae

Retard cavity at the base of the labrum (Plate 8, Figure 22,
ne
REP. ). There is thus formed a very hard chitinous bridge, con-

| sisting of the two modified palpi pressed closely together. The

| ese surfaces of the palpi slope toward the median plane of the
| ody thus forming a trough or groove in which the setae move at

| Weis
Re "

e the ‘point where they enter the labral groove.
yng

ae

- Within the beak, ‘the maxillae are the inner pair of setae

i Plate 8, Figure 23 mx.). They are larger than the mandibles,
| bw , the walls of the maxillae are not quite so heavy as those of
. oT

| the mandibles. Like the mandibles, the maxillae develop as a

re * a

. closed tube, the lateral walls of which grow together in such a
Bey
way as to divide the lumen of the tube into two canals--cne dorsal

mee ite other ventral (Plate 8, Figure 23, lu.). The inner face

of each maxilla bears two grooves such that when the maxillae are
|

Gor baht together, two open tubes are formed. The dorsal tube is

|
1 a larger and is confluent with the phérynx at the base of the

bey —_ % = = = -

»

vis tage Be * at

>

ee “ bats @fe “o) of ioe wee a hae Ds

ie)

Oty Wid ties too! Seth ae

j » of ‘ . alo uy.) eitene
Mig doa @ rerg ae! tl i)

- OH ’ , - vl 747 a aotud yen. 2, ‘
huni wll ta or preety teh at 2 ee ae

ce whee ay

ened below but is free above, and stands out a little from the
opening (Plate 8, Figure 24, v¥.). The ventral tube which is

“sma ler in caliber, connects with the "Wanzenspritze" and opens
ro.

at the distal end in much the same manner as the larger canal

—

(Plate 8, Figure 24, sco ). This canal, however, opens a lit-

ie

i ta
Jere nearer the tips of the maxillae than does the food canal.
‘a

‘The apices tips of the maxillae are very sharp and can readily
pierce the food plant.

4 | The tongue and groove articulations holding the maxillae
"together are very perfectly made and are somewhat complicated

| (Plate 8, Figure 24, mx.a.). These joints hold so perfectly that
iat is almost impossible to separate the maxillae without thruste-
"ing a needle between their bases back within the head of the in-
"sect. The maxillary setae may be moved lengthwise and alternate=
|2y with perfect ease. The joints are so perfectly fitted that
"they are doubtless air tight, especially where the walls of the
\lavfum press upon the setae. In this manner the tubes are per-
“fectly adapted to their offices of conveying the plant juices
[brought up by suction and the saliva forced down by pressure.
\Indeea, this pressure required to force the saliva into the tise

AF

(sues of the food plant, makes this perfect union of the maxillae
la _nesressity. Otherwise, the pressure would doubtless separate
ia setae, and thus destroy the tube. The edges of the maxillae
lere smooth throughout and there are no teeth or barbs near the

“ep such as are found on the mandibles. Only a part of the max-

| ‘|allary fundament is involved in the famation of the finished

LABIUM.

| Me labial anal is larger than the other de aoate which
ri ise to mouth parts, even when the egg is only thirty hours
: past Figure 1, 1i). When the egg is fifty hours old the
merente are prominent and are considerably longer than
a of the mendibles and the maxillae. The fmdaments
ium continue +o develop more rapidly than those of the
Siiasbies ana maxillae and by the time revolution oceurs they are
y three times as long as the maxillary and mandibular funda-
fi ... ... after revolution the labial fundaments begin

at the base (Plate 9, Figure 25 11). This union of the

About vee time, also, the segmentation of the labium
ns (Plate 9, Figure 26, li). The hypophorynx appears at the
' the labium a few hours after revolution (Plate 9, Figure

Just previous to revolution, labial palpi are found laterad

=

fa fundament (Plate 9, Figure 27, li p). After
€ , ; 7

“so * the
rT

J

PP F
3 ntl Find

‘

Oa ot
q oem 4
a f :
i

and the p: pi become still less distinct as development

.”

The labium is by far the most conspicuous of the mouth parts

in the adult insect. It is four-jointed and lies, when at rest,
1 the median ventral line of the body. The labium reaches to the
es of the hind coxae. The groove on the dorsal side of the

am shallow at the base and thus permits the la-

e€ groove deepens and completely envelops the setae. Near

a edge of the Labium Ne ai the other, and the inner

in piercing the food plant. This chitinous projection
| only near the tip of the organ. The labial groove is
formed as soon as the labial fundaments unite, but it is
a short time before the insect emerges. It forms
ne dorsal line of union of the labial fundaments, but not
1 the labium has become a single organ. The apex of the la-
ees with specialized setae which are, doubtless, or-.
> touch. Their position and nature make it impossible to

‘

ee into the food-plant. The simple setae covering

m entering the tissues. The extrene tip of the labium, howev-

while the setae are in action. Such a procedure,

Y rea
a

d.

vie
ies ios 4
_

* a ey

v ‘ae ar.
i eel Pari, ey ni i > a
a i ’ j

wey by observation, seems probable from

ae

Bf sure of the bea Each segment of the labium has a dis-

net of muscles which move it upon the preceding segment.

cles have their origin dorsally at the distal end of the
it ot their insertion on the ventral side of the following
a little behind its distal end. Chitinous tendons assist

at tackment of these muscular fibers. Figure 29, lir,

eeeserenonte the basal seoment of the labium and shows a

muse ele e which bends the organ toward the body. The basal segment

I yeasts to the muscle just mentioned.

Since the labial fundaments in their entirety form the la-
q _tristis, this organ can probably be homologized with
of the mandipulate type. The necessary embryological stu-

(4 es of the mandibulate labium, however, have not been made, and
=

— | these studies, an attempted comparison would doubtless

£

aan 50 error.

PHARYNX.
penie f 26 ih
- The stomodaeal invagination forms the pharynx and the
as usual. Soon after revolution, the outlines of the
7 nous walls and ee of the pharynx may be detected beneath
the labrun and the clypeus. A cross section of the pharynx(Plate
, Figure 30) best illustrates the structure of this organ. A

ee freme-work (Plate 10, Figure 50 f ye with muscular fib-

é 1 ? a :
aaa i i: &

) se . ae .
Niaegee ge lidoe wh nee PR oteifidedie ae

eh 1 APs,» Pe tw Apa =

7
9 % boo’ fetait ads te Uf Gomer inka se oilers

»

am ~ - “om
Cerne Pte a
ie
> yor
hee, Shee ceed dow evar, “got ye iefel See

1 Aas. * ee
. amas mina’ . {

Pode Lae nn le
, “ .- » i ‘ ‘ 4 ae uveyyrs and wy a

=

. te Nang af? betovpuul 64 Dia
ss isa dhe onal
ee ob f2 110) spat aad noe ae vag
o¢ 5S) Liew wtih. -fc® ah gl et 3 bests

‘noe SS et atee: >

. atk Aa ra

yu shaped and is very heevily chitinized and

oo, is Py ewehen’ This plate, mhee in its normal

en. maller chitinous tube connects the pharynx with the dor-
xillary tube. This is accomplished by means of a fine chi-
tube Which enters the maxillary tube at the point where the

sil lee unite. The connection between the maxillary tube

(an the pharynx is avery delicate one, but it serves perfectly

to form a passagew ay from the tips of the maxillae to the pharynx
7
<

when suction begins. Figure 32, Plate 11 illustrates how the

-
.

tam a suction pump of considerable power. When the upper,

ye

% shinner chitinous wall of the pharynx is lifted so as to form

is placed under considerable tension. When the mus-

the piece downwerd to its original position and this forces the
ack into the “= When the ends of this upper piece

re broken, loose they iimied. ‘ teke the pocttien shown in Plate

%

a yy ; p ~~ na
ie ie ¥i i ad oa Le T ; va A

oi A of j ¢ } 2

fea? hae Benge are nt
ia ise tia ec i MH oom Gis Gane <eubhes $05 ut a
a 0) o> eet Baa ; ied Qe et ey: My bi i ‘

+

Stet). acet:

4

a : +9 ‘L. 3 q a ; 3) ERIS OF an © AS
he 7 ‘ ; ire °
i! ites 1 ) genio. . RAgis ’ at! at amt poet th BG

ee
ee ey i? & | Seg: a 12 Wie ont
4 pie
ae wis Ae “acs ; om SG F eet iia
a- . - Pe “
' ‘ i. wr. ay
' ' wis 6, ; ¥
. wel =
i
*¢ ”
'
~ + 4

:
i . ’ 7a 46)) . *euNted, if
'
y

; ie. pt le | Lanigivn pet Ge paren
ae

ew RS ®

“@ ¢

of ' aA if oy dear aunt

» mS iged ats 3

of the fact that elasticity tends to throw the cross
a ie, the piece into circular form. If the ends of an elas-
iece shaped like ie aiden in Plate 11, Figure 33 should

az

led apart and downward for a distance the apne ey, of the
“road the condition of the upper wall of the pharynx.

-inous upper wall tends to coil up, but the edges are se-
eases to the edges of the lower wall. The central por-

40 which the tendons are attached thus moves downward to the

found no vaives in the pharynx, but these are not neces=
swever , for its operations. A rythmic motion of the phar-

al muscles would accomplish the same result as would valves.

anterior muscles, probably contract first and then are followed

‘by the posterior muscles. These muscles doubtless relax
-

atk

WANZENSPRITZE.

‘The hypopharynx, which appears very soon after revolution
ay ‘Figure 26, hy) gives rise to the "Wanzenspritze" (Plate

mre 34). This remarkable organ is situated near the vent-

Fal watt of the teen: It has heavily chitinized walls forming a

= <n E *

ined” 565 8
SS a rs

ortion (Plate 11, Figure 33 c) would be to move downward.

aay order as peal contract. Such action would make valves

— EL. Bilis fsa)

a
" er Leh At OM ie
mee mies he ae ant: ta Tay tte
( c i) ce
‘j Puan a2 send? o2 abowe See Sans
app ti ap to afne an? TD .aSe e iee rH
Aruede £5 6 teplt. 02 @ satel aol eee mit

e4t Yh vortices arf eoraisih = 204 Axpwreol hie:
,h6e8 meh erne of of aioe * 2 init, ri A Oe
trgrada af? ‘to Chew Nene etd ‘fo wh ty hing “an
oie wan meghe of! sus e) ne gs nba phage 4
+405 feufnen eff . si twuwe towor to. vee he wa |
enc 03 Lewipel be ton én “iS - eae sehver |
maa natonm 4ifo Ay a ooh Oran ellh nage
in Jitew CaarveP eft? o° iia ind 44a ®%e eeteniag '
0% wumel®. Gi at 2") s°'c4 ih eee saw:
syouen 363 Go “weds * , ry ea ath leet pw Ula
wifey Oil? TO ite i tom ‘oe ‘a Ak *) ti atten sit! j
aoeviny tigee ta TLliree « » aye as pee S

*
*~

Beeol Ge. awe oemd bap fe tlt 'oe TNO. Vo Nar eee ns
P « 7 ' au ¥
wates ne atideo’ asinete sem (orto ce te aig. '
‘ ‘ s
Gn fae {1 iv yp ip fH 7 ; + “Rs (768 ee i on ; ;

eyi2o@tre fA. OF DTXCH Kev ute O44) JA

ig Pe A?

miideret ~ le nece Yer eter aries
bt) Sage taqaneaint” @49 nt Get ran SS) ws. ae .

\ wrer 64? wea Getre le 1h ae aye ie ie
A a aie low oo eae aed, oe

ay

led aa

et chamber (Plate 12, Figures 34 and 35, ch). This chamber

Brice with inlet and outlet tubes. The inlet tube or sa-
ary - duct, (Plate 12, Figure 35, st) leads from the salivary
ds, empties on the ventral side of the chamber and is provided

a valve to close the opening (Plate 12, Figure 35, iv). This

one branch leading to each of the salivary glands. These
ds are located in the dorsal portion. of the metathorax, and
large, crow-foot shaped organs (Plate 12, Figure 36).
'03) finds the salivary glands of Cicada "in the rear and
of the head," certainly a different location to what

in A. tristis, The salivary reservoir mentioned by some

not found in connection with the salivary ducts.
hese ducts are glandular in structure, long, slender, and are

ally free from convolution. The opening for the passage

Me (Plate 12, Figure 37, od).

-—t

_ ‘The outlet tube, leading from the dorsal side of the chamber
Ee. provided with a valve (Plate 12, Figure Sec OV) ; but this
cture is not so strong as the valve to the inlet tube. The

% valve doubtless serves to prevent the saliva from return-

) the chamber of the "Wanzenspritze" when the piston is drawn

In order to-reach the point where the maxillae unite,

the tube runs very close to the pharyngeal tube previously men-

ets (Plate 11, Figure 32). The connection between the outlet

‘A heavily chitinized dark brown piston (Plate 12, Figures

34 and 55 pa) works hy the chamber of the "Wanzenspritze." This
ston is. aaa at its anterior extremity and appears as though
ae might be a provision for spreading the end of the organ if it
aKeyre uld be thrust forward against the anterior walls of the cham-~
— is drawn backward by a strong chitinous tendon
el 2, Figures 34 and 355, tp). The walls of the chamber ap-
at i uaester ter end where they unite with the tendon

e piston (Plate

{4

2, Figure 35 co). No doubt this wall is
TeX when the strong “pump muscles" attached to the tendon
| contre et ana draw the piston back. The chitinous walls thus drawn
| out « 1s normal position are doubtless placed under consider-
| nsion. When the muscles reiae this elastic piece throws
adel into its original position. When the piston
wn back, the chamber is enlarged and a partial vacuum is |

This permits the entrance of the saliva from the sa-

, ducts and glands and the chamber fills with this fluid.

’

saliva is needed, the muscles relax and the chitinous

hrow the piston forward. This movement closes the inlet

nto contact with the food plant. Ss gliadin this chi-

are “Fron the & anterior portion of the peo gener teze" two chi-

ba
. 0500 are |

pa elt ts ésehe} rotde wert: Pah. bo

Riry. 9.2 Fegan: Aye uth rt erie ae et

aed win mh

a4

meer? om ertemrn Pits ested ilpaten Pree lesa nae Mabe
Sf ome ers 7 Lae ad? ge eid wt “oe
eats 20? Re ah tee sol aptrie ay raise bra hree
Paboaet moet ob: Tet 1? Loge vat ear “rt .
ie weleete nis ‘Yo of lie ac . (og Se ee
NohmG) 64d eet ating yer? socks hi +)!
85 SERP BESS BRIO! om «ion ¢€) 1a Ppa: at ray
Rives At? Jf belinedes “. 9) wake dee
maa). lt? gilivs Lieb? t int? Crear heli ke arPy
ime ume “Abet Decale «oa! ey at win Ghia teenn
BVO1EP Hoar pbtuasl= «35 at. See
ecfcte oe cam oni om Seni se oy GPAL

a! atuody: fuficne eo bauer’ .b a1alne el Tae a:
he
if

we Gas 2uryy agiian wf ” 142 Lee :
ater wie? rice Gl! rt fo ad tan

ee i wi : hal
fate? «@ Poa 3 . Fs it

Le tory Pits ‘ete el iin ' 1, { ¥. ait 2 82

neo. Fh Orel r yA atqn eel! nem sae Te aie

‘trle el: te Mjultinesh Yaw’ Sionfe ponies whe

>»

war ettice «wii. ko "iatingumadade? ir

a

gi vl Sete eb ft te _ibrem my wali

afitty o0@ Sess t's em uc ae” a 2

| agile lk Say |
backward, one on either side of the chamber.

Ere: vroad, ia the muscles which control the piston

4

hese arms and ee which controls the piston.

eae of the “Wanzenspritze" from the hypopharynx

SUMMARY.

t of these segments bears the compound eyes, the second

antennae, while the third gives rise to the labrum.

1 | segment produces the mandibular setae, the fifth the

5 apyendages to appear. They are post-oral in origin and,
ion, become pre-oral just previous to revolution.

1¢ labrum is an evagination of the tritocerebrum and is
rired organ. The oral invagination appears at the base of

the labrum just before revolution. The clypeus takes part in
oo

i ing the sides of the head, while — labrum is grooved to

a

d and guide the setae.

The intercalary segment appears early as the equivalent of ;

pr primary Co een but it disappears before distinct inter-

oars i“ i 5

“<

paren 9
Hite es? pe ae tide

BAe he CPE ER o80 £5) oncik Sag subtest

ER ep

;
. eo mm
(Peteic, ote alovindas ‘atin eas hh hae
/ oe a aie ie + to Ae
,

botintit fia eapn ditbre s ttinntend cate Ete
fe Made hetanl owt 40mm anogty ot

-t '

} ; q
x . . Sens oS
ft

. = ae aa
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i Bevege ets. 20.2 OH ov (? ‘eupnd ahosnie ce

oe

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: an! ety |) it hea ee ow ombimge

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y ae ro “ome ft f 1 Pht eee tLe a ey ;

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ef) tue eiritam: 4 a) 8 } ine ty |
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F i - ’ Ae wigs
, at ti foun : Pe Wi iw r ra )

on

a! ' ie eg of a ‘ : : ‘ fo) 7% ‘of Yi) WA ae }
“ 4s
*, ifs Ce om J PA t " a : “4 ria & Ya | Is iv ‘oh ‘ef
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hs, iy)
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| ‘
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| Wi aneiewtiigy o8 ao haw Mnpeiah aan
; ~tint graefevtr 21> ted arontend ie a3 au . : ay

° : O \iere > _ o vy
S a. AP es pp Anaeee,

dament is involved in forming the seta. The fundaments

to the metathorax, where they coil up until emergence. At

;
: the finished mandibular organ migrates quickly into

she bec where it remains. To this base the muscles be~

ee may be obtained readily.
bh alg
1 regard to their formation, situation, and migration, the

r r setae are. jike those of the mandible. The maxillary | :

Se bear palpi, which’ firmly’ form a bridge con= Kh

ye of these canals conveys saliva from the "Wanzen-
echs food plant, and the other canal conveys fluid from
nt te the pharynx. ‘The maxillee are so completely joined

ha they may move on each other longitudinally, but

no lateral motion. The apices of these setae are
p and readily pierce the food plant.
e four-jointed labium is formed just after revolution by

ion of the paired fundaments of the labiel segment. These

Ee shortly before emergence. It is broad and
he base of the organ, but for most of its length,

meee pe it acts as a mechanical support

1fer Gi

oe fete
Waa? at a

4a, 4 , : ic [Apap

LAG TOT eri

o*ad «ft ti th

eco i@ Lariteanoan iawn

> Li oi hee, vy oi

® mandables and the maxillae, and takes no part

ec position, follows the outline of the ventral lamella.
a elastic lamella is moved by means of a series of strong
les | attached to the dorsal wall of the head. The contraction
the Beupacles produces a partial vacuum. The organ thus be-
ms mst pump. The pharynx is connected with the anterior

» and the food is consequently pumped up’ this canal
i” - pharynx. A rythmic motion of the upper wall of the
pr rm af orces the food into the aesophagus.

"Wanzenspritze" is formed from the hypopharynx. The
essentiatty « a force pump which supplies the setae with
‘The "Wanzenspritze" is provided with inlet and outlet

rates which open and close as the piston works back and forth
he chamber. The piston is drawn back by the strong "pump
"

-* and it is thrown forward by the elasticity of the chiti-

4
J 2

Ane : | ;

), Leon ('87), Smith ('92), Marlatt ('92), Karawajirf ('93)
yk (103). Geise and Wedde each discussed the pharynx and

enspritze" at some length. Geise speaks of the Puarynx

Sap-as having many cutting and grinding processes,

oe A
7 Ebr! 3) hi
<< »

»

2 ull ot oll ae a : See aa

= refers to that of py-rthocgris_apterus Sag heiHE:"S

e unmodified tube." In A. tristis the inner walls of the

4
2) ee

ial are smooth throughout. The tube, however, is much modi-

In e tristis the maxillary palpi are functional, but serve a pur-

pose very different, indeed, from the usual function of these ore

‘This fact suggests that embryological studies might reveal

5
=
\ hai

a
the
f

se am similarly modified in other Hemiptera. The disap-

'_

pearance of the labial palpi has been previously described. Leon's
lconclusion that the labium is composed of submentum, mentum,

{=

glossae, ead paragiossee is certainly premature since given, with-
out ‘the corresponding embryological data on the mandibulate labium.

‘” _ With preconceived ideas as to what the parts of the hemip-
: serous mouth represent, Smith ('92), allowed himself to propose
ij

nomologies which he calls "revolutionary," and which any one mak-
’ a,

la yet it is doubtful if this sclerite had its origin in the

pas embryological investigations must certainly call "imaginary."

pronounces the so-called “mandibular sclerite" the true man-

ihe
he mdibular fundament. He says that the maxillae are represented
iby two setae, yet in Ae tristis one pair of these setae comes di-
me

|rectly from the mandibular fundaments and the other pair from the

ta
¥ 5
'

1 Cg -

iY

a

i

xillary fundaments. He represents the labium as a part of the
maxillae, also; yet in a tristis it may be traced from the labial
‘fundamentes through every stage to that of the finished beak. Mar-
latt justly criticises Smith for his "erroneous conception," but

|

Me latt himself faiis into the error of saying that the labium is

Lo ‘
.

ey eer

ie Iie
ait Ve e( lum garnet afd abs

q “a
« , 7 pt
sues. hamlet tev seur: «dy eee aw 176
Et ; =
OCRLS; Of a’use™ i s solrtgbnpeel quniveny . nie nk

“ Mw af Bawuw pes bt as z “PGing tte (ites « ert? L 3

4
> } { ? r ‘ f 1
2 : ; { i "
= ” + » i
: . I ‘ i 4 ‘ fe [
LO oh ite Taf gi te , queen
7 ; j “4 ‘ ‘ ; » ; vt é we wy ~~
- é r] 7
= (te = 4 ® ' i OM
. - -
ibe Bail ’ a

at ’ ‘ ; by f i ba "D>
tw thy 2 ¥. "lane
. t os - AGO
f i"

' cy 1
ie * a w
s . =; 4 é ,
imat hag i? GF wagdita Pise-

EF odak

.

ia
cee a

a os one. My own figures of A. tris

y eee and Meek have investigated the mouth-parts

Marlatt and Meek are probably correct in most of their

put they both reach, from purely anatomical dats,

ons. which need. Hie additional evidence to be furnished by

ogical studies. Valuable as anatomical studies are, they

and. slow, but they are essen-

|| Ayers, H.
1884.

Brandt, A.
1869.

BIBLIOGRAPHY.

On the Development of Oecanthus niveus and its Para-
site, Teleas. Mem. Bost. Soc... Nat. Hist. Vol. 3, No.

8. 56 pp. Plates 18-25, 41 Fig.

Beitrage zur Entwicklungsgeschichte von Libelluliden’

und Hemipteren. 33 pp., 3 Taf. Leipzig.

Folsom, J. W.

1899.

1900.

Geise, 0.

1883.

Heider, XK.
1889.

Heymofts ? R >
1895,

Karawajeff,

1893.

The Anatomy and Physiology of the Mouth-Parts of the
Collembolan Orchesella cincta. Bull. Mus. Comp. Zool.
Vol. 35, No. 2, pp. 7-59, 4 pl.

The Development of the Mouth-Parts of Anurida mari-
tima Guer. Bull. Mus. Comp. Zool. Vol. 36, No. 5,
pp. 87-157. 8 pl.

Die Mundtheile der Rhynchoten. Archiv fur Naturge-
schichte. Vol 49, I, pp. 515-575, i Taf.

Embryonalentwicklung von Hydrophilus Piceus. 98 PPey
13 Taf. 9 Fig.

Die Embryonalentwickelung von Dermapteren und Orthop-
teren. 1356 pp. 12 Taf. 23 Fig. Jena.
W.

Zur Embryondalentwicklung von Pyrrhocoris apterus.

2 pa
Sua? wht fae anevtc wax tnacedian Pepe vai wi

Ao. «fev .deth.. dat oO (oR Lee epee” a :
ae
sit Dat er nade tt opaee

Meri

i.
ay

‘Heat tol hadh? vow afr ctdeteps qretyalete’ aoe

mierias “int ‘ +35 pon | s is

| meee
Sf 30 afvatiernavitt ef? ic eno lLélegir tine Peary
Phe? . caf, mune (Jie wnt lo StteweteeOeuaniee

# f":eur wehbe Te &2'ae f ~<!.) ree
eo ae a afiey 4006: . aman

—e eck wy vicos telco corey wh ofredi
. Ww r Fd ‘ 5¢ = 1% . gt) . I ‘ ’ fy , a 2
eng °F .ayGolT evillsvorhy) pov mov Olelwinetean

we ? ei

=wedrs) twy edges aol SUL LARO ME So L<ro ide

«4.407 alg £4 et ict aid At 7s
iv
as

te ee eT
ee

g ¢
ae -
Saar
¥

34 pps 2! Tab.

ie?
or

| . 2. and Heider, K.
te
hel Lehrbuch der vergleichenden Entwicklungsgeschichte
| der wirbellosen Thiere.
Te Beitrage zur Kentniss der Mundteile der Hemipteren.

47 PPeyl Taf. vena,

895, The Hemipterous Mouth. Proc. Ent. Soc. Washington.

“1905. On the “youth-parts of the Hemiptera. Kansas Uni-
ath

,e
e

versity Sci. Bull. Vol. 2, pp. 257-277, Pl. 7-11.

’ ete A Text-Book of Raceway: pp. 515-591, Fig 482-557.

‘1sas. Beitrage zur Kentniss des Rhynchotenrussels. Archiv

Cs

fur Naturgeschichte. Vol. 51, I,pp. 115-143, 2 Taf.

Ot it thineyhgey. Cin tweet poking te tay “aa!
peeled aia

reads

nella eek al/letive) ~ab et tacit. way
ae) Wee

(fongridaeh bot wg. oot! pier eg
ss +f = se bits ee abe ‘a é '

tee tq aie

T¢ Fs

%

‘ ;
‘ j | rig Le
, “Lay. quite ® wiridgine F640 pf oneee fc
> a ¢ ro ve
= et f+? ok? gees “es “AG sg Pap ts vo CCUG. ae
| ae: A
aTAP=ths oPE .£GA=4F2 on |. ee once ae
S
» Lo? y tok oft fyi em: guna pi an rag 5 i
La sei? anne we ‘ 4 i tu @
‘ .. Fig |
fafey ~ elersvarefoderes? «(; eaidines We
(wt & <af-t e tuct £0 . (20 ein? BEE tp | ie

eee the "Wanzenspritze."

aa

wall.

ec

compound eyes.

eh--=-=- ‘et ember °

“

‘ af: :
ad ypeus.

eee ane Seppe reste pharynx.

bod Ke.

Cc ----fo¢ 0d. canal.
; 4 . +

ter opening of food canal.

anglion cells. *

a

» of setae at time of emergence.

Lae projection in labial groove.

-- extensor of labium.

—

a

7 n Awe a |

| ee \

:

» *

Ai Vale hoe ;
. ‘

UNL TR RETA TRY re aa:
mae? al ont tr mee

;

| 7 Fi 9s ene Ls dy
‘ °

:

| | Tie Fag |
| Oona te Eee

jlu---- lumen of wecan.

jm=-~~~-- muscle.

imd==-- mandible.

jmd a-- mandibular articulation.
lmd p-~- projecting piece on mandible.
jmd se- serration on mandible.

imu s-- muscular sheath of setae.
mx---- maxillae.

jmx a-- maxillary articulation.
mx p---maxillary palpus.

0 ---=~ pharyngeal opening.
— opening of salivary duct.
ov---- outlet valve.

pr---- pharynx.

pl---- protocerebral lobes.
pm---- pharyngeal muscles.

pn---- piston.

fep=--- posterior pole of egg.
a selivary canal of maxillae.
jscoO--- Opening of salivary canal.
se --. serosa.

sm---- muscles of "Wanzenspritze."

st---- tubes to salivary glands.

th=--- thorax.

> tendon of piston.

|tr---- tritocerebral segment.
v----~- valve closing opening to food canal.

vi---- ventral lamella of pharynx.
\W------ "Wanzenspritze."
\y----~ yolk.

PLATE I.

¢ | Fig. 1. Ventral aspect of the primary head segments and

hours old. xX 125. 7

Fig. 2. Oblique aspect of the same regions of the germ F

band shown in Fig. 1. Egg about thirty-cne hours

Ps

rae old. X 125. _
oe A:

PLATE ITI.

Ventral aspect of germ band when the egg is | titty
hours old. X 78. > Sao a

Lateral aspect of first four abdominal segments
just previous to emergence, showing abdominal ap-

nS

pendages. X 125. ; rc)

Head segments of germ band from egg Pree .

hours old. X 8. £250
iow

Relative positions of oy thes and antennae at seven-

ty-seven hours old. X 125.

a

PLATE III.

Fig. 7. Paramedian section from egg 100 hours old. Right

aspect. Revolution beginning. X 98.

@

Fig. 8. Paramedian section from same set of eggs as Fig. —

7. Left aspect. In process of revolution. X 98.

x rh anh"
re oy ee ie et, :

PLATE IV.

Fig. 9. Paramedian section from egg of same set as Fig. 7.

”

Ee
Right aspect. Revolution nearing completion. X 98.
| | = ae
Fig. 10. Frontal aspect of head a few hours after revolu-

Signs, 2225,

oF

- —_— — << ——E 5
¥ = 4 yy oe . z 5
« 7 ams
9

PLATE V.

Fig. 11. Outlines of cross section through base of beak
and labrum of ene x 98.
Fig. 12, Outlines of cross section through middle hiss’ labrum
of same nymph agthig. lis KK 98,
Fig. 15. Outlines of cross section near tip of labrum of |
same nymph as, Fig. Lie eae.
Fig. 14, Mandiblar and maxillary fundaments coiled in meta-
thorax previous to emergence. X52, 4

Fig. 15. Position of muscular sheaths on setae immediately
‘i

before emergence.X 93, . PS

|
| | i.

PLATE VI,

Fig. 16. Position of muscular sheath on seta immediately
after emergence. Figures 15 and 16 are drawn from
specimens from the same set of eggs. X 125. =

Fig. 17. Maxillary fundament with palpus and groove. From
ege about L4ghours oid. xX 185. |

Fig. 18. Cross section of mandible. X 650.

ii

y
:

PLATE VII.

Fig. 19. Cross section of setae in normal er Nymph.

First segment. X 1350. “i

| Fig. 20. Lateral aspect of tip of sinannies xX 1350. on
‘Fig. 21. Maxillary fundament at time of pereiueiae x 650.

hos >
>

] - a | ~ "we a ia =

PLATE VIII.

Fig. 22. Median sagittal section of head of nymph. Relative
positions of pharynx, Wanzenspritze, labrum, |
; ry i

maxillary palpus. X 52.

Fig. 23. Cross section of setae in normal position. Nymph.

ee:
Third segment of same specimen as Fig. 19. X 1350.
ee

Fig. 24. Tips of maxillae, one seta raised. Nymph. X 1350.

PLATE IX.

Labial fundaments. Egg 102 hours old. X 98.

Labium and hypopharynx. Egg 115 hours old. X 98.

Labial fundament and palpus. Just before revo- —
lution. X 125.

Cross section of labium near tip.

PLATE X.

Fig. 29. Sagittal section through base of labium. x aa.

Fig. 30. Cross section of pharynx. X 52.

PLATE XI.

Cross section of open pharynx. X 650. :

a 4
7

Lateral aspect of pharynx and "Wanzenspritze." —

Tubes leading to union of maxillae. X 180,
Cross section of dorsal lamella of pharynx with

edges free from ventral lamella. X 650.

mi

ae

RE rece. |

7

¥ —_

PLATE XII.

Fig. 34, "Wanzenspritze." X 98. . a
Fig. 35. Sagittal section through chamber and piston of _
: a

"Wanzenspritze." X 1350.

* 4

4°

. a.

Fig. 36. Salivary gland. X 125. -

Pig. 37. Cross section of tube leading from salivary

glands. X 1350.

Me

©) Ta) 5

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SISSIES OSOISTISISIIS TIA

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= : | | , | : | * . a ee
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AIS PAILS ; //1\\ } fl Sali AN wi// AM hi iif =] Sai] : la ; : * . om | om |
S SS [ [ , \ Mh yl! | y / \ stas/ / ‘ bi/ ‘ \ SALi/ i = , s }
f rE ——s —- oo =— cS C Jian TESSSNy HS SAS NYAS WY, ARS HW) ; Y NY //
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AS SSA AN SS SV, SV) SE. We STF. NS
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ii