this sound of terror proceeded, some attributing it to a kind of
wood-louse, as I lately observed, and others to a spider; but it is
a received opinion now, adopted upon satisfactory evidence, that it
is produced by some little beetles belonging to the timber-boring
genus _Anobium_. Swammerdam observes, that a small beetle, which
he had in his collection, having firmly fixed its fore legs, and
put its inflexed head between them, makes a continual noise in old
pieces of wood, walls, and ceilings, which is sometimes so loud,
that upon hearing it, people have fancied that hobgoblins, ghosts,
or fairies were wandering around them[620]. Evidently this was one
of the death-watches. Latreille observed _Anobium striatum_ produce
the sound in question by a stroke of its mandibles upon the wood,
which was answered by a similar noise from within it. But the species
whose proceedings have been most noticed by British observers is _A.
tessellatum_. When spring is far advanced, these insects are said to
commence their ticking, which is only a call to each other, to which
if no answer be returned, the animal repeats it in another place. It
is thus produced. Raising itself upon its hind legs, with the body
somewhat inclined, it beats its head with great force and agility
upon the plane of position; and its strokes are so powerful as to
make a considerable impression if they fall upon any substance softer
than wood. The general number of distinct strokes in succession is
from seven to nine or eleven. They follow each other quickly, and are
repeated at uncertain intervals. In old houses, where these insects
abound, they may be heard in warm weather during the whole day. The
noise exactly resembles that produced by tapping moderately with the
nail upon the table; and when familiarized, the insect will answer
very readily the tap of the nail[621].
The queen bee has long been celebrated for a peculiar sound, producing
the most extraordinary effects upon her subjects. Sometimes, just
before bees swarm,--instead of the great hum usually heard, and
even in the night,--if the ear be placed close to the mouth of the
hive, a sharp clear sound may be distinguished, which appears to be
produced by the vibration of the wings of a single bee. This, it has
been pretended, is the harangue of the new queen to her subjects, to
inspire them with courage to achieve the foundation of a new empire.
But Butler gives to it a different interpretation. He asserts, that
the candidate for the new throne is then with earnest entreaties,
lamentations, and groans, supplicating the queen-mother of the hive
to grant her permission to lead the intended colony;--that this is
continued, before she can obtain her consent, for two days; when the
old queen relenting gives her fiat in a fuller and stronger tone. That
should the former presume to imitate the tones of the sovereign, this
being the signal of revolt, she would be executed on the spot, with
all whom she had seduced from their loyalty[622].--But it is time to
leave fables: I shall therefore next relate to you what really takes
place. You have heard how the bees detain their young queens till they
are fit to lead a swarm.--I then mentioned the attitude and sound that
strike the former motionless[623]. When she emits this authoritative
sound, reclining her thorax against a comb, the queen stands with her
wings crossed upon her back, which, without being uncrossed or further
expanded, are kept in constant vibration. The tone thus produced is a
very distinct kind of clicking, composed of many notes in the same key,
which follow each other rapidly. This sound the queens emit before they
are permitted to leave their cells; but it does not then seem to affect
the bees. But when once they are liberated from confinement and assume
the above attitude, its effects upon them are very remarkable. As soon
as the sound was heard, Huber tells us, bees that had been employed
in plucking, biting, and chasing a queen about, hung down their heads
and remained altogether motionless; and whenever she had recourse to
this attitude and sound, they operated upon them in the same manner.
The writer just mentioned observed differences both with regard to the
succession and intensity of the notes and tones of this royal song;
and, as he justly remarks, there may be still finer shades which,
escaping our organs, may be distinctly perceived by the bees[624]. He
seems however to doubt by what means this sound is produced. Reasoning
analogically, the motion of the wings should occasion it. We have
seen that they are in constant motion when it is uttered. Probably
the intensity of the tones and their succession are regulated by the
intensity of the vibrations of the wings. Reaumur remarks, that the
different tones of the bees, whether more or less grave or acute, are
produced by the strokes, more or less rapid, of their wings against
the air, and that perhaps their different angles of inclination may
vary the sound. The friction of their bases likewise against the sides
of the cavity in which they are inserted, as in the case of the fly
lately mentioned, or against the base-covers (_Tegulæ_), may produce
or modulate their sounds, a bee whose wings are eradicated being
perfectly mute[625]. This last assertion, however, is contradicted by
John Hunter, who affirms that bees produce a noise independent of their
wings, emitting a shrill and peevish sound though they are cut off, and
the legs held fast[626]. Yet it does not appear from his experiment
that the wings were eradicated. And if they were only cut off, the
friction of their base might cause the sound. I have before noticed the
remarkable fact, that the queens educated according to M. Schirach's
method are absolutely mute; on which account the bees keep no guard
around their cells, nor retain them an instant in them after their
transformation[627].
The _passions_, also, which urge us to various exclamations, elicit
from insects occasionally certain sounds. Fear, anger, sorrow,
joy, or love and desire, they express in particular instances by
particular noises. I shall begin with those which they emit when
under any _alarm_. One _larva_ only is recorded as uttering a cry
of alarm, and it produces a perfect insect remarkable for the
same faculty: I allude to _Acherontia Atropos_. Its caterpillar,
if disturbed at all, draws back rapidly, making at the same time
a rather loud noise, which has been compared to the crack of an
electric spark[628].--You would scarcely think that any _quiescent
pupæ_ could show their fears by a sound,--yet in one instance this
appears to be the case. De Geer having made a small incision in the
cocoon of a moth, which included that of its parasite Ichneumon (_I.
Cantator_, De G.), the insect concealed within the latter uttered
a little cry, similar to the chirping of a small grasshopper,
continuing it for a long time together. The sound was produced by the
friction of its body against the elastic substance of its own cocoon,
and was easily imitated by rubbing a knife against its surface[629].
But to come to _perfect_ insects. Many beetles when taken show their
alarm by the emission of a shrill, sibilant, or creaking sound--which
some compare to the chirping of young birds--produced by rubbing
their elytra with the extremity of their abdomen. This is the case
with the dung-chafers (_Geotrupes vernalis_, _stercorarius_, and
_Copris lunaris_); with the carrion-chafer (_Trox sabulosus_); and
others of the lamellicorn beetles. The burying-beetle (_Necrophorus
Vespillo_), _Lema melanopa_ and _merdigera_, and _Hygrobia Hermanni_,
and many other _Coleoptera_, produce a similar noise by the same
means. When this noise is made, the movement of the abdomen may be
perceived; and if a pin is introduced under the elytra it ceases.
Long after many of these insects are dead the noise may be caused by
pressure. Rösel found this with respect to the _Scarabæidæ_[630],
and I have repeated the experiment with success upon _Necrophorus
Vespillo_. The capricorn tribes (_Prionus_, _Lamia_, _Cerambyx_,
&c.) emit under alarm an acute or creaking sound--which Lister calls
querulous, and Dumeril compares to the braying of an ass[631]--by the
friction of the thorax, which they alternately elevate and depress,
against the neck, and sometimes against the base of the elytra[632].
On account of this, _Prionus coriarius_, is called _the fiddler_ in
Germany[633]. Two other coleopterous genera, _Cychrus_ and _Clytus_,
make their cry of _Noli me tangere_ by rubbing their thorax against
the base of the elytra. _Pimelia_, another beetle, does the same by
the friction of its legs against each other[634]. And, doubtless,
many more _Coleoptera_, if observed, would be found to express their
fears by similar means.
In the other orders the examples of cries of terror are much less
numerous. A bug (_Cimex subapterus_, De G.) when taken emits a
sharp sound, probably with its rostrum, by moving its head up and
down[635]. Ray makes a similar remark with respect to another bug
(_Reduvius personatus_), the cry of which he compares to the chirping
of a grasshopper[636]. _Mutilla europæa_, a hymenopterous insect,
makes a sibilant chirping, as I once observed at Southwold, where it
abounds; but how produced I cannot say. The most remarkable noise,
however, proceeding from insects under alarm, is that emitted by the
death's-head hawk-moth, and for which it has long been celebrated.
The _Lepidoptera_, though some of them, as we have seen, produce a
sound when they fly, at other times are usually mute insects: but
this alarmist--for so it may be called, from the terrors which it
has occasioned to the superstitious[637]--when it walks, and more
particularly when it is confined, or taken into the hand, sends forth a
strong and sharp cry, resembling that of a mouse, but more plaintive,
and even lamentable, which it continues as long as it is held. This cry
does not appear to be produced by the wings; for when they, as well as
the thorax and abdomen, are held down, the cries of the insect become
still louder. Schrœter says that the animal, when it utters its cry,
rubs its tongue against its head[638]; and Rösel, that it produces it
by the friction of the thorax and abdomen[639]. But Reaumur found,
after the most attentive examination, that the cry came from the mouth,
or rather from the tongue; and he thought that it was produced by the
friction of the palpi against that organ. When, by means of a pin,
he unfolded the spiral tongue, the cry ceased; but as soon as it was
rolled up again between the palpi it was renewed. He next prevented the
palpi from touching it, and the sound also ceased; and upon removing
only one of them, though it continued, it became much more feeble[640].
Huber, however, denies that it is produced by the friction of the
tongue and palpi[641]: but as he has not stated his reasons for this
opinion, I think his assertion that he has ascertained this cannot be
allowed to countervail Reaumur's experiments.
I must next say a few words upon the angry chidings of our little
creatures; for their _anger_ sometimes vents itself in sounds. I have
often been amused with hearing the indignant tones of a humble-bee
while lying upon its back. When I held my finger to it, it kicked and
scolded with all its might. Hive-bees when irritated emit a shrill
and peevish sound, continuing even when they are held under water,
which John Hunter says vibrates at the point of contact with the
air-holes at the root of their wings[642]. This sound is particularly
sharp and angry when they fly at an intruder. The same sounds, or
very similar ones, tell us when a wasp is offended, and we may expect
to be stung;--but this passion of anger in insects is so nearly
connected with their fear, that I need not enlarge further upon it.
Concerning their shouts of _joy_ and cries of _sorrow_ I have little
to record: that pleasure or pain makes a difference in the tones of
vocal insects is not improbable; but our auditory organs are not
fine enough to catch all their different modulations. When Schirach
had once smoked a hive to oblige the bees to retire to the top of
it, the queen with some of the rest flew away. Upon this, those that
remained in the hive sent forth a most plaintive sound, as if they
were all deploring their loss; when their sovereign was restored
to them, these lugubrious sounds were succeeded by an agreeable
humming, which announced their joy at the event[643]. Huber relates,
that once when all the worker-brood was removed from a hive, and only
male brood left, the bees appeared in a state of extreme despondency.
Assembled in clusters upon the combs, they lost all their activity.
The queen dropped her eggs at random; and instead of the usual active
hum, a dead silence reigned in the hive[644].
But _love_ is the soul of song with those that may be esteemed
the most musical insects, the grasshopper tribes (_Gryllina_ and
_Locustina_), and the long celebrated Cicada. You would suppose,
perhaps, that the ladies would bear their share in these amatory
strains. But here you would be mistaken--female insects are too
intent upon their business, too coy and reserved to tell their love
even to the winds.--The males alone
"Formosam resonare docent Amaryllida sylvas."
With respect to the _Cicadæ_, this was observed by Aristotle; and
Pliny, as usual, has retailed it after him[645]. The observation also
holds good with respect to the _Gryllina_, &c., and other insects,
probably, whose love is musical. Olivier however has noticed an
exception to this doctrine; for he relates, that in a species of beetle
(_Moluris striata_), the female has a round granulated spot in the
middle of the second segment of the abdomen, by striking which against
any hard substance, she produces a rather loud sound, and that the
male, obedient to this call, soon attends her, and they pair[646].
As I have nothing to communicate to you with respect to the love-songs
of other insects, my further observations will be confined to the
tribes lately mentioned, the _Gryllina_, &c. and the _Cicadæ_.
No sound is to me more agreeable than the chirping of most of the
_Gryllina_, _Locustina_, &c.; it gives life to solitude, and always
conveys to my mind the idea of a perfectly happy being. As these
creatures are now very properly divided into several genera, I shall
say a few words upon the song of such as are known to be vocal,
separately.
The remarkable genus _Pneumora_--whose pellucid abdomen is blown up
like a bladder, on which account they are called _Blaazops_ by the
Dutch colonists at the Cape--in the evening, for they are silent
in the day, make a tremulous and tolerably loud noise, which is
sometimes heard on every side[647]. The species of this genus have a
much greater claim to the name of _Fiddlers_, than the insect lately
mentioned, since their sound is produced by passing the hind-legs
over a number of short transverse elevated ridges on the abdomen,
which may be called their _fiddle-strings_[648].
The _cricket_ tribe are a very noisy race, and their chirping
is caused by the friction of the bases of their elytra against
each other. For this purpose there is something peculiar in their
structure, which I shall describe to you. The elytra of both sexes
are divided longitudinally into two portions; a vertical or lateral
one, which covers the sides; and a horizontal or dorsal one, which
covers the back. In the female both these portions resemble each
other in their nervures; which running obliquely in two directions,
by their intersection form numerous small lozenge-shaped or
rhomboidal meshes or areolets. The elytra also of these have no
elevation at their base. In the males the vertical portion does not
materially differ from that of the females; but in the horizontal the
base of each elytrum is elevated so as to form a cavity underneath.
The nervures also, which are stronger and more prominent, run here
and there very irregularly with various inflexions, describing
curves, spirals, and other figures difficult and tedious to
describe, and producing a variety of areolets of different size and
shape, but generally larger than those of the female: particularly
towards the extremity of the wing you may observe a space nearly
circular, surrounded by one nervure, and divided into two areolets
by another[649]. The friction of the nervures of the upper or
convex surface of the base of the left-hand elytrum--which is the
undermost--against those of the lower or concave surface of the base
of the right-hand--which is the uppermost one--will communicate
vibrations to the areas of membrane, more or less intense in
proportion to the rapidity of the friction, and thus produce the
sound for which these creatures are noted.
The merry inhabitant of our dwellings, the house-cricket (_Gryllus
domesticus_), though it is often heard by day, is most noisy in the
night. As soon as it grows dusk, its shrill note increases till it
becomes quite an annoyance, and interrupts conversation. When the
male sings, he elevates the elytra so as to form an acute angle with
the body, and then rubs them against each other by a horizontal and
very brisk motion[650]. The learned Scaliger is said to have been
particularly delighted with the chirping of these animals, and was
accustomed to keep them in a box for his amusement. We are told
that they have been sold in Africa at a high price, and employed to
procure sleep[651]. If they could be used to supply the place of
laudanum, and lull the restlessness of busy thought in this country,
the exchange would be beneficial. Like many other noisy persons,
crickets like to hear nobody louder than themselves. Ledelius relates
that a woman, who had tried in vain every method she could think of
to banish them from her house, at last got rid of them by the noise
made by drums and trumpets, which she had procured to entertain her
guests at a wedding. They instantly forsook the house, and she heard
of them no more[652].
The field-cricket (_Gryllus campestris_) makes a shrilling
noise--still more sonorous than that of the house-cricket--which
may be heard at a great distance. Mouffet tells us, that their
sound may be imitated by rubbing their elytra, after they are taken
off, against each other[653]. "Sounds," says Mr. White, "do not
always give us pleasure according to their sweetness and melody;
nor do harsh sounds always displease.--Thus the shrilling of the
field-cricket, though sharp and stridulous, yet marvellously delights
some hearers, filling their minds with a train of summer ideas of
every thing that is rural, verdurous, and joyous." One of these
crickets when confined in a paper cage and set in the sun, and
supplied with plants moistened with water--for if they are not wetted
it will die--will feed, and thrive, and become so merry and loud, as
to be irksome in the same room where a person is sitting[654].
Having never seen a female of that extraordinary animal the
mole-cricket (_Gryllotalpa vulgaris_), I cannot say what difference
obtains in the reticulation of the elytra of the two sexes. The male
varies in this respect from the other male crickets, for they have no
circular area, nor do the nervures run so irregularly; the areolets,
however, toward their base are large, with very tense membrane. The
base itself also is scarcely at all elevated. Circumstances these,
which demonstrate the propriety of considering them distinct from the
other crickets. This creature is not however mute. Where they abound
they may be heard about the middle of April singing their love-ditty
in a low, dull, jarring, uninterrupted note, not unlike that of
the goat-sucker (_Caprimulgus europæus_), but more inward[655]. I
remember once tracing one by its shrilling to the very hole, under a
stone, in the bank of my canal, in which it was concealed.
Another tribe of grasshoppers (_Acrida_, _Pterophylla_,
&c.[656])--the females of which are distinguished by their long
ensiform ovipositor--like the crickets, make their noise by the
friction of the base of their elytra. And the chirping they thus
produce is long, and seldom interrupted, which distinguishes it from
that of the common grasshoppers (_Locusta_). What is remarkable,
the grasshopper lark (_Sylvia locustella_), which preys upon them,
makes a similar noise. Professor Lichtenstein in the _Linnean
Transactions_ has called the attention of naturalists to the eye-like
area in the right wing of the males of this genus[657]; but he seems
not to have been aware that De Geer had noticed it before him as
a sexual character; who also, with good reason, supposes it to
assist these animals in the sounds they produce. Speaking of _Acrida
viridissima_--common with us--he says, "In our male grasshoppers,
in that part of the right elytrum which is folded horizontally over
the trunk, there is a round plate made of very fine transparent
membrane, resembling a little mirror or piece of talc, of the tension
of a drum. This membrane is surrounded by a strong and prominent
nervure, and is concealed under the fold of the left elytrum, which
has also several prominent nervures answering to the margin of the
membrane or ocellus. There is," he further remarks, "every reason to
believe that the brisk movement with which the grasshopper rubs these
nervures against each other, produces a vibration in the membrane
augmenting the sound. The males in question sing continually in the
hedges and trees during the months of July and August, especially
towards sun-set and part of the night. When any one approaches they
immediately cease their song[658]."
The last description of singers that I shall notice amongst the
_Locustina_, and which includes the migratory locust, are those that
are more commonly denominated grasshoppers. To this genus belong the
little chirpers that we hear in every sunny bank, and which make vocal
every heath. They begin their song--which is a short chirp regularly
interrupted, in which it differs from that of the _Acridæ_--long before
sun-rise. In the heat of the day it is intermitted, and resumed in the
evening. This sound is thus produced:--Applying its posterior shank
to the thigh, the animal rubs it briskly against the elytrum[659],
doing this alternately with the right and left legs, which causes the
regular breaks in the sound. But this is not their whole apparatus of
song--since, like the Tettigoniæ, they have also a tympanum or drum.
De Geer, who examined the insects he describes with the eye of an
anatomist, seems to be the only entomologist that has noticed this
organ. "On each side of the first segment of the abdomen," says he,
"immediately above the origin of the posterior thighs, there is a
considerable and deep aperture of rather an oval form, which is partly
closed by an irregular flat plate or operculum of a hard substance,
but covered by a wrinkled flexible membrane. The opening left by this
operculum is semi-lunar, and at the bottom of the cavity is a white
pellicle of considerable tension, and shining like a little mirror. On
that side of the aperture which is towards the head, there is a little
oval hole, into which the point of a pin may be introduced without
resistance. When the pellicle is removed, a large cavity appears. In my
opinion this aperture, cavity, and above all the membrane in tension,
contribute much to produce and augment the sound emitted by the
grasshopper[660]." This description, which was taken from the migratory
locust (_L. migratoria_), answers tolerably well to the tympanum of
our common grasshoppers, only in them the aperture seems to be rather
semicircular, and the wrinkled plate--which has no marginal hairs--is
clearly a continuation of the substance of the segment. This apparatus
so much resembles the drum of the Cicadæ, that there can be little
doubt as to its use. The vibrations caused by the friction of the
thighs and elytra striking upon this drum, are reverberated by it, and
so intenseness is given to the sound. In Spain, we are told that people
of fashion keep these animals--called there _Grillo_--in cages, which
they name _Grilleria_, for the sake of their song[661].