Article beginning on page 159.
Psyche 5:159-164, 1888.

Full text (searchable PDF)
Durable link: http://psyche.entclub.org/5/5-159.html

The following unprocessed text is extracted from the PDF file, and is likely to be both incomplete and full of errors. Please consult the PDF file for the complete article.

ON THE OCCURRENCE OF ORGANS PROBABLY OF TASTE IN THE EPIPHARYNX OF THE MECAP rERA (PANORPA AND BOREUS).
BY ALPHEUS SPRING PACKARE, PROVIDENCE, R. I. From the observations of Meinert,
Forel, Kraepelin and Will anatomical
and experimental proofs have been af-
forded of the existence of organs of
taste on the parts of the maxillae near
the mouth, and also on the lingua or
&'tongue" of-ants, wasps and bees ; while Lubbock, in his recent excellent work
"On the senses,"etc. of animals, claims
that the organs discovered by Wolff in
the mouth-parts of the lower hymen-
optera, e.g., tezth~edi~idae, eva~ii-
dae, chalcididcxe and fwoctoh-zjz'dac
are also those of taste.
I have obsei-ved organs such as W ill1
describes and figures (his figs. I, 8, 8a, 9, I I, 16, etc.), which he calls "ge-
schmacksbecher" and Lubbock translates
as L6 taste-cups,'' in the mounted prepara- tions of the mouth-pasts of the honey
bee and a species of BOTPZ~S, kindly
loaned me by Mr. N. N. Mason, of
Providence. In the honey bee they are
most abundant in the paraglossae situ-
ated at the base of the tongue and at
the end of the furrow.
Each paraglos-
sa bears about 22-27 taste-CLIPS, in my
specimen 22 on the left, and 27 on the
right paraglossa ; on the inside, near the base of each labial palpus, and opposite the middle of the paraglossae are situ-
ated a group of exactly similar taste-
cups, which are, however, rather like
pegs than sunken CLIPS or pits ; they are protected in front by a few defensive
spin~~les ; and there ai-e about 30 on each side.
In the Eomhus, the left paraglossa
bears about 28 taste-pegs arranged in
irregular oblique rows ; on the right ase 28. On the base of the labial palpi, the taste-cups are less peg-shaped, more like cups, the rods being shorter and smaller while the rim of thecup is more marked.
The terminal joint of the maxillae of
Vespa ?nacdata have no taste-cups, but
about 35 taste-rods, which are much
longer than those of Veq5a vulgayis
figured by Will.
I have also observed the taste-cups
in the epipharynx of the honey bee.
1 Das gescl~maclssorgan der insecten. (Zeitschrift fiir wissensch . zool., 1885 v, 42, p. 674.)
Taste-cups OE the ejz'$ha~ynx of




================================================================================

160 S'.Y ?THE. [February-March IS@.
Pa~or$a dehiZis Westw ?, and Boreas
caZifowzicus Pack.-Having tl~~is be-
come in a degree familiar with the or-
gans so clearly described and figured
by Will, I was pi-eparecl to look for
them in other insects. It was not ~lntil I 11ad found them in the epipharynx of
Pa~o~$a and BO~WAY, that 1 was aware
that other observers had already noticed them. In his historical s~~ininai-y Will states that G. Joseph
in 1877 inen-
tions that in almost all orders of insects, but especiall)~ in those living on plants, we find at the base of the tongue, in the region of the throat and the palate, little cl~ps, wl~icl~ shoiild be regarded as or- gans of taste. Ktinckel and Gazagnaii-e8 (1 88 I) fo~incl in VoZuceZla si~nilar or- gans on the paraglossae (labella), on
the end of the epiphasynx and at the
beginning as well as thro~~gliout the
whole extent of the pharj~nx. Will does
not seem to have seen the elaboi-ate
plates of these a~ithors in the second past of theis great work on VoZuceZZa, where
the mouth-parts of VoZuceZZu4 ai-e beau- tifully figtired bz Gazagnaise with nu-
merous figuses of n~icroscopic sections of the proboscis and of the epiplmrynx and
hypophary~x, inclnding excellent histo-
logical details showing the gustatory
ZJo~ep11, Gust. ZLU morphologie des gesclimack~or- gmes bei insekten.
( 4mtlicller beridit der so. Ver-
sammlung deutsche~ naturforsc11e1- LI. Arzte in 1%ii11- cllen, ~Sij, p. 227-22s.)
3 Du s2ge de 1:~ g~~station chez les imectes dipteres. Constit~~tion anato~nique et physiologique de 1'6pipha- ryiix et 1' hypopliarpx. (Comptes rendns, 1881, Y. 95, P- 3+i-350-)
4 Recherclies snr l'organization et le dkveloppe- ment des diptkres et en particdaire des volncelles de la famille des syphides, part I, 1Sj5, part 2. ISSI, only the plates and their explanations.
cups, cells and nerves. The taste-cups we have seen in the insects mentioned be-
low are similar to those figured by Gaz- agnaire, and, judging by their appear-
ance and position where the fluids en-
ter the mouth, there seems little do~~bt that these pits 01- cups, with their pro- jecting sods or fine setae are true organs of taste.
Oui- own observations are very super-
ficial, no attempt having been made to
study the parts l~istologically . or by imicso- scopic sections, so as to work out the
nerves and ganglion cells. We have
simply dissected out the
pasts, placed
them for a few min~ites in a mixture of
carbolic acid, I part, and oil of tui-pen- tine 4 parts, with a drop or two of dilute liquor potassae. This clears the parts,
rendering thein transparent, so that they can be at once placecl in the aniinalcule- box and examined under the microscope.
A word or two as to the hoinologies
of the epipl~arynx imay not be out of
place. Little attention has been paid to the nature of this organ, and it is most desirable that a caref~il and comparative st~~dy of it be made. Morpl~ologically
it is the phaspgeal lining of the labr~iin and clypeus, and seems to be present in
all insects. In the higher lepidoptera
(inacsos) what has been regarded as
the labrum is called by Dr. Walter5
the epipharynx, In the hymenoptem it
forms a short fold situated under the pro- jecting labrum. What in the inecaptera
5 Wdte~, Alfred. BeitrXge zur inorphologie der scliinetterlinge. Ier theil. Z L ~ morphologie der sclmet- terlings~~~~~~~dtheile. (Jena. zeitschr., 1885, v, IS, 11. s., v. 9.1




================================================================================

we call the parepipharynx is apparently
the pale, non-chitinous, sensitive end of the labruni. It is in Paaorpa a pdatal
fold or outgrowth, and in Boreus it is
directly conti~~uous with the labruin. For convenience) therefore, we will call this soft) non-chitinous, whitish l~ighly sensi- tive fold projecting beyond the labr~m the parepiphai-ynx. And here it may be said
that a very close relationship appears to exist between the parepipharynx of $a%-
orpidae and of the microlepidoptei-a,
especially the tz'ceidae) and in this point the $azorpidae are quite unlike the
neuroptera as restricted by Brauei- and
myself, which do not have a par-
epipharynx. In fact the pare pipharynx
appeal-s to be mainly developed in the
s~~ctorial insects, such as the hyinenop- tera, lepidoptesa and diptei-a, and also the mecaptera, but is not well devel-
oped in exclusively biting insects) which have the mandibles well developed.
Dr. Walter's figure and account of
the labsuin and epipharynx of &!ic~o$-
te/--yx .semi$~r$u?*eZZa is of special in- tei-est in connection with the structui-e of the homologous parts in Bweus. In
the tineid in question) the five-sided or rather tsiangulas, narrow, horny labruin is hollowed out at the end, the hollow
being filled by the pale, sub-membranous p-wepipharynx, which projects out from
under the labi-um and completes the apex of the triangle made by the two organs
collectively. Now the labrum-epi-
phai-ynx of Bo~eus and Pmzor$a, is
1-athes long, narrow and triangular ;' in Pawo~ja the labrum ends in a corneons
point, and the epiphai-ynx forms two
pale, membranous flaps on each side, as
seen fl-oin above ; in Boreus, however,
the labrum ends in an obtuse point, and
in fact appears at fisst as if hollowed out, as th2re are two dark thickened inandible- like portions on each side of the labsum) free from setae and sensory pits. The
parepiphai-ynx forms a pale whitish,
obtu:ely pointed projection of the end of the labsum, and is not, as in Pacor$a,
divided into lobes extending along the
sides towards the base of the labrum.
I regard the structure of* the labrum-
epipharynx of the mecaptera) and on
the other hand the interesting discovery by Waltes of the primitive lepidopter-
011s inaxilla of flficro$te~yx caZteJZa
with the lacinia (the homologue of one
half of the '' tongue") and the galea, be- sides the maxillary palpus, asvery strong proof of the origin of lepidoptera from
mecaptera-like foi-ms. Walter does
not state how nearly the shape of the
galea of the Afiwo$teqm in question
cori-esponds to that of the true neurop- tera (in sensu Brauer) b~tt it is notice- able.
To return to the sense-01-gans devel-
oped in the labrum-epipharynx. The
sensory organs are of two kinds i. e.,
taste-cups (Will) and taste-rods) besides tactile hairs and defensive setae, as well as what seem to be "gathering hairs"
(Cheshire).
In Panor$a debilis? the labrum as
seen from above is acutely triangular and edged with a single, slightly irregular
row of long) stiff defensive setae which project a little beyond the edge of the
epipharynx, both in front and on the




================================================================================

162 P S ~ C ' ~ ~ . i February-March 1839. side. In both the inale and female on
each side near the base of the epiphai-ynx, is a group of about 20-25 taste-cups,
each giving rise to a short hair. There
are also scattered taste-CLIPS near a point corresponding to the end of the labi-um. On the upper side of the free edge of the epipliarynx, there are scattered taste-
CLIPS, varying in size, and like those
already ii~entioned, though some of them are witho~it perceptible hairs.
At the end of the epipharynx in the
female are several gustatory pegs oi-
rods ; but in the ii~ale examined they
seeinecl to be more numerous, there
being a group of two sl~ost stout ones
in tlie middle, one on each side of the
median line of the body ; and a group of four larger ones on each side of the ceii- ti-a1 pair.
On tlie ~~iider side of the epipliarynx
these is a striking varietj- of hairs, differ- ing ~LICII in cliaracter and vai-iously
grouped. L4rouiid the edge of the an-
terior divisio~~ of the organ, there is a single row of very long, rather stout
setae, apparently tactile, possiblj- both tactile and defensive. The edge, liow-
ever, of the basal division of the epi-
pliasynx, is thickly fringed with long
slender hair-like setae, flattened and tri- angular at the base. Three of the setae
are larger than the others and spin~~lose. The gi-eater part of tlie organ is fl-ee from hairs, there being only two gro~ips near the imiddle of fine slender hairs
which are flattened and broad at the
base ; these, like those fringing the
edge of the basal division, in shape
resemble the 'Lgatl~ering" hairs of the
bee's proboscis, and are evidently for
the purpose of collecting and amassing
moisture,
whether the saliva or the li-
quids entering the inouth, 01- both) we
cannot say. Tliese delicate gathering
hairs, i. c., those which are very slender and flexible and arising from a flat-
tened triangular base, as we ha~e seen
in Vesfia wzaculaia and Nemazks erich-
sozii? line the pharynx, above and be-
neath, though of varying sizes and mode
of grouping. Indeed) the epipharynx
is simply a coiitin~~ation and o~~tgrowth of the roof of the inouth. The exact
function of these hairs remains to be
detei-mined. They seem to be, so to
speak? colossal chitinous cilia, serving at times to retain the saliva or liquid food in certain places, and in otliei-s to facili- tate the passage of the food down the
th1-oat.
The labr~~iii-epipl~arynx of &'orem
calz~oraic~~s is q~lite different in shape from that of Panoqh ; it is a little
longel- than broad, not dorsally separ-
ated by a distinct transvei-se suture from the clypeus, though laterally separated
by a distinct notcll. The labsum itself
is not longer than broad, and not exca-
vated in fkoiit, b ~ ~ t on the contrary sonie- what produced, extending into the base of the parepipl~arynx. Neal+ the base at each side is a dai-k chitino~~s triaiigular thick- ening of the shape of a mandible, but
not dentate at the end. Between the
base of these mandible-like thickenings
is a group of four taste-cups, protected on the inside by three defensive setae.
On each side
of the median line of the
labnim, and exteiding back under what




================================================================================

February-March 18S9.] Z'S2THE. 163
appears to be the end of the clype~~s ai-e two narsow thickenings of the surface,
along which are scattered taste-cups,
there being about 20 on each side of the median lines6 There is also a taste-cup on an asea corresponding to the thin, front edge of the labrum, about midway be-
tween the most distal taste-cup, and the tip of the mandible-like thickening.
While the epipharynx of Paaoyj5a
scarcely projects beyond the acute end
of the labrum, and is apparently di-
vided into two large lateral divisions,
and moreover is divided into a basal and distal poi-tion (a somewhat significant
fact in connection with the possibility
that the labi-urn i-epresents a pair of ap- pendages) ; in Bo~eus the parepipharynx
extends well beyond the end of the
labrum, and shows no signs of a division into lateral or longitudinal lobes. It is a somewhat crescent-shaped whitish fold,
tending in front of the labsum to a dis- tance nearly half its width. There are
no taste-cups on it, but around the edge a series of about 16 large taste-rods,
which project as far as the marginal
hairs situated between them. They are
considerably, about twice, as long as
those at the extremity of the epipharynx of Pa~orj5a.
All of the hairs appear to be of the
6 It should be observed in view of the figures by Dr. W. Patten, Studies on the eyes of arthropods, Journ. morphology, July, 1838, v. 2, PI. 7, p. 1-7, of the labrum of AciJius, which appears to answer to a pair of limbs representing a first pair of antennae; that in Boreus, besides the bilateral mandible-like thicken- ings the labrum also appears to be slightly divided 4
along the middle by these two parallel ridges or thick- enings, giving rise to the
appearance of an obsolete
median suture.
But this needs further exam ination.
I< ind clenominated gathering hairs, and we do not appear to have the marked
diffei-entiation into different kinds of hairs and setae noticeable in the epipha- rynx of Pa~o~-$a. They are in Boreus
arranged in about six curvilinear series ; and are bi-oad at the base, not triangu- lar, but with pasallel sides until in the middle they suddenly conti-act into hairs. They are probably neither specially tac- tile or protective, but rather adapted for gathering liquids and promoting their
flow down the throat,
Taste-cu$s oz. the labium a~a' %ax-
iZhe of Pazoy$a.-In the same species
(P. debilis?) I have noticed taste-cups
on the labium in two regions ; a group
of five or six on the upper surface,
on each side at the base of the first or basal joints? also a group of about a
dozen on each side of a region includ-
ing the base of the labium and end of
the mentum. These taste-cups are char-
acterized by having a short minute haii- arising fi-om the centre of the cup.
They were observed in the male, but
undoubtedly occur in the other sex? as I have not as yet observed any sexual dis- tinctions in this group as regards the
distribution either of gustatosy or olfac- tory organs.
In the maxillae of the same species
there asE in-both sexes a few taste-cups? protected by long defensive setae on the stipes neas the base of the palpi ; and in the inale I noticed a group of five such pits at the base of the lacinia, while
others are scattered along the outei edge, near the base of the singular series of
marginal comb-like sets of flattened,




================================================================================

[February-March 1889.
curved, scraping hairs.
A few taste-
cups were also noticed scattered in a
row along the outer edge of the plea
of the female.
Taste-cups on the maxillae of Bo-
reus californicus.-No taste-cups were
observed on the labium of Boreus,
which is very different
in shape from
that of Panorpa^ unless four or five pits protected by two or three spines and sit- uated at the base of the palpi are such. On the basal region of the galea of the
maxillae, however, there is a series of
taste-pits, the basal one the largest. No hair arises from the centre, and the pits are protected in front and on the outside by unusually short and stout peg-like
defensive setae.
The structure of both the labium and
maxillae of the imecaptei-a is very inter- esting, hut space forbids our entering
into farther details.
Olfactory rods on the palpi of Pan-
orpa and Boreus.-At the end of the
second or distal joint of the labial palpi of Panorpa is the usual pale area, bear- ing about 18 small short rods, which are probably olfactory ; these are as usual
roughly arranged in two series, and by
groups.
The last joint of the maxillary
palpi bears olfactory rods of the size and number of those in the labial palpi.
The end of the distal joint of the very
short labial palpi of Boreq is provided
with about ten small olfactory rods which are slightly larger than those of the max- illary palpi.
The rather acute end of the maxillary
palpi terminates in a pale clear space
through which can be dimly seen the
nerves leading to the seven or eight
olfactory rods, which themselves are a
little smaller than those of the labial
palpi. Also at the distal end of the
second joint are four sensory pits.
The oifactory pits of the antennae
of Pano~pa and Boreus.-In the ter-
minal antennal joint of the female of
Panorpa there are to be seen on one
side about 35 olfactory pits scattered ir- regularly among the setae. In both
sexes of Boreus-, there are to be seen on one side of the last joint about eight
olfactory pits, none at the end ; on the penultimate joint there are on one side
five pits, three in a row on one side,
two on the other ; the third and fourth
joints from the end have two on the side next to the observer, the fifth and sixth one each.
Of course the exact function of these
antennal pits is hypothetical until deter- mined by repeated experiment ; but
provisionally they may be regarded as
olfactory in their nature.
In conclusion we may say that by the
use of the creosote and oil of turpentine mixture, the sense-organs can be easily