LETTER XXIV.

It is remarkable that the smallerTipulariæwill fly unwetted in a heavy shower of rain, as I have often observed. How keen must be their sight, and how rapid their motions, to enable them to steer between drops bigger than their own bodies, which, if they fell upon them, must dash them to the ground!

Amidst this infinite variety of motions, for purposes so numerous and diversified, and performed by such a multiplicity of instruments and organs, who does not discern and adore the GreatFirst Mover? From him all proceed, by him all are endowed, in him all move: and it is to accomplish his ends, and to go onhis errands, that these little but not insignificant beings are thus gifted; since it is by them that he maintains this terraqueous globe in order and beauty, thus rendering it fit for the residence of his creature man.

I am, &c.

That insects, though they fill the air with a variety of sounds, have novoice, may seem to you a paradox, and you may be tempted to exclaim with the Roman naturalist, What, amidst this incessant diurnal hum of bees; this evening boom of beetles; this nocturnal buz of gnats; this merry chirp of crickets and grasshoppers; this deafening drum of Cicadæ, have insects no voice! If by voice we understand sounds produced by the air expelled from the lungs, which, passing through the larynx, is modified by the tongue, and emitted from the mouth,—it is even so. For no insect, like the larger animals, uses its mouth for utterance of any kind: in this respect they are all perfectly mute; and though incessantly noisy, are everlastingly silent. Of this fact the Stagyrite was not ignorant, since, denying them a voice, he attributes the sounds emitted by insects to another cause. But if we feel disposed to give a larger extent to this word; if we are of opinion that all sounds, however produced, by means of which animals determine those of their own species to certain actions, meritthe name of voice; then I will grant that insects have a voice. But, decide this question as we will, we all know that by some means or other, at certain seasons and on various occasions, these little creatures make a great din in the world. I must therefore now bespeak your attention to this department of their history.

In discussing this subject, I shall consider the noises insects emit—during their motions—when they are feeding, or otherwise employed—when they are calling or commanding—or when they are under the influence of the passions; of fear, of anger, of sorrow, joy, or love.

The only kind oflocomotionduring which these animals produce sounds, is flying: for though the hill-ants (Formica rufa), as I formerly observed[600], make a rustling noise with their feet when walking over dry leaves, I know of no other insect the tread of which is accompanied by sound—except indeed the flea, whose steps, a lady assures me, she always hears when it paces over her night-cap, and that it clicks as if it was walking in pattens! That the flight of numbers of insects is attended by a humming or booming is known to almost every one; but that the great majority move through the air in silence, has not perhaps been so often observed. Generally speaking, those that fly with the most force and rapidity, and with wings seemingly motionless, make the most noise; while those that fly gently and leisurely, and visibly fan the air with their wings, yield little or no sound.

Amongst the beetle tribes (Coleoptera), none is more noticed, or more celebrated for "wheeling its droningflight," than the common dung-chafer (Geotrupes stercorarius) and its affinities. Linné affirms—but the prognostic sometimes fails—that when these insects fly in numbers, it indicates a subsequent fine day[601]. The truth is, they only fly in fine weather. Mr. White has remarked, that in the dusk of the evening beetles begin to buz, and that partridges begin to call exactly at the same time[602]. The common cock chafer, and that which appears at the summer solstice (Melolontha vulgarisandAmphimalla solstitialis), when they hover over the summits of trees in numbers, produce a hum somewhat resembling that of bees swarming. Perhaps some insect of this kind may occasion the humming in the air mentioned by Mr. White, and which you and I have often heard in other places. "There is," says he, "a natural occurrence to be met with in the highest part of our down on the hot summer days, which always amuses me much, without giving me any satisfaction with respect to the cause of it;—and that is a loud audible humming of bees in the air, though not one insect is to be seen.—Any person would suppose that a large swarm of bees was in motion, and playing about over his head[603]."

"Resounds the living surface of the ground—Nor undelightful is the ceaseless humTo him who muses through the woods at noon,Or drowsy shepherd as he lies reclined."

The hotter the weather, the higher insects will soar; and it is not improbable that the sound produced by numbers may be heard, when those that produce it are out of sight.—The burying-beetle (Necrophorus Vespillo),whose singular history[604]so much amused you, as well asCicindela sylvaticaof the same order, flies likewise, as I have more than once witnessed, with a considerable hum.

Whether the innumerable locust armies, to which I have so often called your attention, make any noise in their flight, I have not been able to ascertain; the mere impulse of the wings of myriads and myriads of these creatures upon the air, must, one would think, produce some sound. In the symbolical locusts mentioned in the Apocalypse[605], this is compared to the sound of chariots rushing to battle: an illustration which the inspired author of that book would scarcely have had recourse to, if the real locusts winged their way in silence.

Amongst theHemiptera, I know only a single species that is of noisy flight; though doubtless, were the attention of entomologists directed to that object, others would be found exhibiting the same peculiarity. The insect I allude to (Coreus marginatus) is one of the numerous tribe of bugs; when flying, especially when hovering together in a sunny sheltered spot, they emit a hum as loud as that of the hive-bee.

From the magnitude and strength of their wings, it might be supposed that manylepidopterousinsects would not be silent in their flight;—and indeed many of the hawk-moths (Sphinx, F.), and some of the larger moths (Bombyx, F.), are not so;Cossus ligniperda, for instance, is said to emulate the booming of beetles by means of its large stiff wings; whence in Germany it is called the humming-bird (Brumm-Vogel).—But the great body ofthese numerous tribes, even those that fan the air with "sail-broad vans," produce little or no sound by their motion. I must therefore leave them, as well as theTrichopteraandNeuroptera, which are equally barren of insects of sounding wing—and proceed to an order, theHymenoptera, in which the insects that compose it are, many of them, of more fame for this property.

The indefatigable hive-bee, as she flies from flower to flower, amuses the observer with her hum, which, though monotonous, pleases by exciting the idea of happy industry, that wiles the toils of labour with a song. When she alights upon a flower, and is engaged in collecting its sweets, her hum ceases; but it is resumed again the moment that she leaves it.—The wasp and hornet also are strenuous hummers; and when they enter our apartments, their hum often brings terror with it. But the most sonorous fliers of this order are the larger humble-bees, whosebombination,booming, orbombing, may be heard from a considerable distance, gradually increasing as the animal approaches you, and when, in its wheeling flight, it rudely passes close to your ear, almost stunning you by its sharp, shrill, and deafening sound. Many genera, however, of this order fly silently.

But the noisiest wings belong to insects of thedipterousorder, a majority of which, probably, give notice of their approach by the sound of their trumpets. Most of those, however, that have a slender body,—the gnat genus (Culex) excepted,—explore the air in silence. Of this description are theTipulariæ, theAsilidæ, the genusEmpis, and their affinities. The rest are more or less insects of a humming flight; and with respect tomany of them, their hum is a sound of terror and dismay to those who hear it. To man, the trumpet of the gnat or mosquito; and to beasts, that of the gad-fly; of various kinds of horse-flies; and of the Ethiopian zimb, as I have before related at large[606], is the signal of intolerable annoyance. Homer, in hisBatrachomyomachia, long ago celebrated the first of these as a trumpeter—

"For their sonorous trumpets far renown'd,Of battle the dire charge mosquitos sound."

Mr. Pope, in his translation, with his usual inaccuracy, thinking no doubt to improve upon his author, has turned the old bard's gnats into hornets. In Guiana these animals are distinguished by a name still more tremendous, being called the devil's trumpeters[607]. I have observed that early in the spring, before their thirst for blood seizes them, gnats when flying emit no sound. At this moment (Feb. 18) two females are flying about my windows in perfect silence.

After this short account of insects that give notice when they are upon the wing by the sounds that precede them, I must inquire by what means these sounds are produced. Ordinarily, except perhaps in the case of the gnat, they seem perfectly independent of the will of the animal; and in almost every instance, the sole instruments that cause the noise of flying insects are their wings, or some parts near to them, which, by their friction against the trunk, occasion a vibration—as the fingers upon the strings of a guitar—yielding a sound more or less acute in proportion to the rapidity of theirflight—the action of the air perhaps upon these organs giving it some modifications. Whether, in the beetles that fly with noise, the elytra contribute more or less to produce it, seems not to have been clearly ascertained: yet, since they fly with force as well as velocity, the action of the air may cause some motion in them, enough to occasion friction. With respect toDiptera, Latreille contends that the noise of flies on the wing cannot be the result of friction, because their wings are then expanded; but though to us flies seem to sail through the air without moving these organs, yet they are doubtless all the while in motion, though too rapid for the eye to perceive it. When the aphidivorous flies are hovering, the vertical play of their wings, though very rapid, is easily seen; but when they fly off it is no longer visible. Repeated experiments have been tried to ascertain the cause of sound in this tribe, but it should seem with different results. De Geer, whose observations were made upon one of the flies just mentioned, appears to have proved that, in the insect he examined, the sounds were produced by the friction of the root or base of the wings against the sides of the cavity in which they are inserted. To be convinced of this, he affirms, the observer has nothing to do but to hold each wing with the finger and thumb, and stretching them out, taking care not to hurt the animal, in opposite directions, thus to prevent their motion,—and immediately all sound will cease. For further satisfaction he made the following experiment. He first cut off the wings of one of these flies very near the base; but finding that it still continued to buz as before, he thought that the winglets and poisers, which he remarked were in a constant vibration,might occasion the sound. Upon this, cutting both off, he examined the mutilated fly with a microscope, and found that the remaining fragments of the wings were in constant motion all the time that the buzzing continued; but that upon pulling them up by the roots all sound ceased[608]. Shelver's experiments, noticed in my last letter, go to prove, with respect to the insects that he examined, that the winglets are more particularly concerned with the buzzing. Upon cutting off the wings of a fly—but he does not state that he pulled them up by the roots—he found the sound continued. He next cut off the poisers—the buzzing went on. This experiment was repeated eighteen times with the same result. Lastly, when he took off the winglets, either wholly or partially, the buzzing ceased. This, however, if correct, can only be a cause of this noise in the insects that have winglets. Numbers have them not. He next, therefore, cut off the poisers of a crane-fly (Tipula crocata), and found that it buzzed when it moved the wing. He cut off half the latter, yet still the sound continued; but when he had cut off the whole of these organs the sound entirely ceased[609].

Aristophanes in hisClouds, deriding Socrates, introduces Chærephon as asking that philosopher whether gnats made their buz with their mouth or their tail[610]. Upon which Mouffet very gravely observes, that the sound of one of these insects approaching is much more acute than that of one retiring; from whence he very sapiently concludes, that not the tail but the mouth must be their organ of sound[611]. But after all, the frictionof the base of the wings against the thorax seems to be the sole cause of the alarming buz of the gnat as well as that of otherDiptera. The warmer the weather, the greater is their thirst for blood, the more forcible their flight, the motion of their wings more rapid, and the sound produced by that motion more intense. In the night—but perhaps this may arise from the universal stillness that then reigns—their hum appears louder than in the day: whence its tones may seem to be modified by the will of the animal.

Sounds also are sometimes emitted by insects when they arefeedingor otherwiseemployed. The action of the jaws of a large number of cockchafers produces a noise resembling the sawing of timber; that of the locusts has been compared to the crackling of a flame of fire driven by the wind; indeed the collision at the same instant of myriads of millions of their powerful jaws must be attended by a considerable sound. The timber-borers also—theBuprestes; the stag-horn beetles; and particularly the capricorn-beetles—the mandibles of whose larvæ resemble a pair of mill-stones[612]—most probably do not feed in silence. A little wood-louse (Atropos pulsatoria)—which on that account has been confounded with the death-watch—is said also, when so engaged, to emit a ticking noise.—Certain two-winged flies seen in spring, distinguished by a very long proboscis (Bombylius), hum all the time that they suck the honey from the flowers; as do also many hawk-moths, particularly that called from this circumstance the humming-bird (Macroglossa Stellatarum), which, while it hovers over them, unfolding its long tongue, pilfers their sweets withoutinterrupting its song.—The giant cock-roach (Blatta gigantea), which abounds in old timber houses in the warmer parts of the world, makes a noise when the family are asleep like a pretty smart rapping with the knuckles—three or four sometimes appearing to answer each other.—On this account in the West Indies it is called theDrummer; and they sometimes beat such a reveille, that only good sleepers can rest for them[613]. As the animals of this genus generally come forth in the night for the purpose of feeding, this noise is probably connected with that subject.

Insects also, at least many of the social ones, emit peculiar noises while engaged in their variousemployments. If an ear be applied to a wasps or humble-bees nest, or a bee-hive, a hum more or less intense may always be perceived. Were I disposed to play upon your credulity, I might tell you, with Gœdart, that in every humble-bees nest there is a trumpeter, who early in the morning, ascending to its summit, vibrates his wings, and sounding his trumpet for the space of a quarter of an hour, rouses the inhabitants to work! But since Reaumur could never witness this, I shall not insist upon your believing it, though the relater declares that he had heard it with his ears, and seen it with his eyes, and had called many to witness the vibrating and strepent wings of this trumpeter humble-bee[614].—The blue sand-wasp (Ammophila? cyanea), which at all other times is silent, when engaged in building its cells emits a singular but pleasing sound, which may be heard at ten or twelve yards distance[615].

Some insects also are remarkable for a peculiar mode ofcalling,commanding, or giving analarm. I have before mentioned the noise made by the neuters or soldiers amongst the white ants, by which they keep the labourers, who answer it by a hiss, upon the alert and to their work[616]. This noise, which is produced by striking any substance with their mandibles, Smeathman describes as a small vibrating sound, rather shriller and quicker than the ticking of a watch. It could be distinguished, he says, at the distance of three or four feet, and continued for a minute at a time with very short intervals. When any one walks in a solitary grove, where the covered ways of these insects abound, they give the alarm by a loud hissing, which is heard at every step[617].—"When house-crickets are out," says Mr. White, "and running about in a room in the night, if surprised by a candle they give two or three shrill notes, as it were for a signal to their followers, that they may escape to their crannies and lurking-holes to avoid danger[618]."

Under this head I shall consider a noise before alluded to[619], which has been a cause of alarm and terror to the superstitious in all ages. You will perceive that I am speaking of the death-watch—so called, because it emits a sound resembling the ticking of a watch, supposed to predict the death of some one of the family in the house in which it is heard. Thus sings the muse of the witty Dean of St. Patrick on this subject:

"..................A wood-wormThat lies in old wood, like a hare in her form:With teeth or with claws it will bite or will scratch,And chambermaids christen this worm a death-watch;Because like a watch it always cries click;Then woe be to those in the house who are sick!For, sure as a gun, they will give up the ghost,If the maggot cries click, when it scratches the post;But a kettle of scalding hot water injected,Infallibly cures the timber affected:The omen is broken, the danger is over,The maggot will die, and the sick will recover."

To add to the effect of this noise, it is said to be made only when there is a profound silence in an apartment, and every one is still.

Authors were formerly not agreed concerning the insect from which 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 genusAnobium. 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 observedAnobium striatumproduce 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 isA. tessellatum. When spring is far advanced, theseinsects 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 permissionto 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, ashe 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].

Thepassions, 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 anyalarm. Onelarvaonly is recorded as uttering a cry of alarm, and it produces a perfect insect remarkable for the same faculty: I allude toAcherontia 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 anyquiescent pupæcould 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 toperfectinsects. 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, andCopris lunaris); with the carrion-chafer (Trox sabulosus); and others of the lamellicorn beetles. The burying-beetle (Necrophorus Vespillo),Lema melanopaandmerdigera, andHygrobia Hermanni, and manyotherColeoptera, 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 theScarabæidæ[630], and I have repeated the experiment with success uponNecrophorus 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 calledthe fiddlerin Germany[633]. Two other coleopterous genera,CychrusandClytus, make their cry ofNoli me tangereby 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 moreColeoptera, 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 hymenopterousinsect, 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. TheLepidoptera, 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 bythe 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 theirangersometimes 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 ofjoyand cries ofsorrowI 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].

Butloveis the soul of song with those that may be esteemed the most musical insects, the grasshopper tribes (GryllinaandLocustina), 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 theCicadæ, this was observed by Aristotle; and Pliny, as usual, has retailed it after him[645]. The observation also holds good with respect to theGryllina, &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 observationswill be confined to the tribes lately mentioned, theGryllina, &c. and theCicadæ.

No sound is to me more agreeable than the chirping of most of theGryllina,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 genusPneumora—whose pellucid abdomen is blown up like a bladder, on which account they are calledBlaazopsby 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 ofFiddlers, 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 theirfiddle-strings[648].

Thecrickettribe 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. Theelytra 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 tokeep 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 theLinnean Transactionshas 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 ofAcrida 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 theLocustina, 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 theAcridæ—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 theright 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 elytrastriking 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 thereGrillo—in cages, which they nameGrilleria, for the sake of their song[661].

I shall conclude this diatribe upon the noises of insects, with a tribe that have long been celebrated for their musical powers: I mean theCicadiadæ, including the generaFulgora,Cicada,Tettix, andTettigonia[662]. TheFulgoræappear to be night-singers, while theCicadæsing usually in the day. The great lantern-fly (Fulgora laternaria), from its noise in the evening—nearly resembling the sound of a cymbal, or razor-grinder when at work—is calledScare-sleepby the Dutch in Guiana. It begins regularly at sun-set[663]. Perhaps an insect mentioned by Ligon as making a great noise in the night in Barbadoes, may belong to this tribe. "There is a kind of animal in the woods," says he, "that I never saw, which lie all day in holes and hollow trees, and as soon as the sun is down begin their tunes, which are neither singing nor crying, but the shrillest voices I ever heard: nothing can be so nearly resembled to it as the mouths of a pack of small beagles at a distance; and so lively and chirping the noise is, as nothing can be more delightful to the ears, if there were not too much of it; for the music hath no intermission till morning, and then all is husht[664]."

The species of the other genus,Cicada, called by the ancient Greeks—by whom they were often kept in cages for the sake of their song—Tettix, seem to have beenthe favourites of every Grecian bard from Homer and Hesiod to Anacreon and Theocritus. Supposed to be perfectly harmless, and to live only upon the dew, they were addressed by the most endearing epithets, and were regarded as all but divine. One bard entreats the shepherds to spare the innoxious Tettix, that nightingale of the Nymphs, and to make those mischievous birds the thrush and blackbird their prey. Sweet prophet of the summer, says Anacreon, addressing this insect, the Muses love thee, Phœbus himself loves thee, and has given thee a shrill song; old age does not wear thee out; thou art wise, earth-born, musical, impassive, without blood; thou art almost like a god[665]. So attached were the Athenians to these insects, that they were accustomed to fasten golden images of them in their hair, implying at the same time a boast that they themselves, as well as the Cicadæ, wereTerræ filii. They were regarded indeed by all as the happiest as well as the most innocent of animals—not, we will suppose, for the reason given by the saucy Rhodian Xenarchus, when he says,

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