Fig. 12.—Superior wing.a, marginal cell;b, first cubital or submarginal cell;c, second ditto;d, third ditto;eandf, first and second recurrent nervures.
Fig. 12.—Superior wing.a, marginal cell;b, first cubital or submarginal cell;c, second ditto;d, third ditto;eandf, first and second recurrent nervures.
Fig. 12.—Superior wing.a, marginal cell;b, first cubital or submarginal cell;c, second ditto;d, third ditto;eandf, first and second recurrent nervures.
Attached to the mesothorax in the centre, above and behind, are the scutellum and post-scutellum, which in colouring or form often yield subsidiary generic or specific characters. On each side of the mesothorax in front, above the pectus, or breast, and just below and before the articulation of the anterior wings, there is asmall tubercle, or boss, separated from the surrounding integument by a suture, the colouring of which frequently yields a specific character, but its uses are not known.
Fig. 13.—Posterior legs:1, of abnormal bee (Andrena);2, scopuliped normal bee (Eucera);3, parasitic bee (Nomada).a, coxa;b, trochanter, with flocculus;c, femur;d, tibia;e, planta;f, spinulæ;g, tarsus, with its claws.
Fig. 13.—Posterior legs:1, of abnormal bee (Andrena);2, scopuliped normal bee (Eucera);3, parasitic bee (Nomada).a, coxa;b, trochanter, with flocculus;c, femur;d, tibia;e, planta;f, spinulæ;g, tarsus, with its claws.
Fig. 13.—Posterior legs:1, of abnormal bee (Andrena);2, scopuliped normal bee (Eucera);3, parasitic bee (Nomada).a, coxa;b, trochanter, with flocculus;c, femur;d, tibia;e, planta;f, spinulæ;g, tarsus, with its claws.
Themetathoraxcarries the posterior legs laterally beneath, and in the centre, behind, the abdomen. The posterior legs are the chief organs used by the majority of bees for the conveyance of pollen to store in their cells, or, as in the case of humble-bees or the hive bee, the bee bread for the food for the young, or the requisite materials, in the majority of other bees, for nidification. To this end they are either densely clothed with hair throughout their whole extent,—usually externally only,—or this is limited to the external surface of the posterior shank. In the social bees this shank is edged externally with stiff bristles. In these, as in most of the bees, this limb greatly and gradually expands towards its articulation with theplanta, or first joint of the tarsus; and this surface, which is perfectly smooth, serves to the social bee as a sort of basket to hold and convey the collected materials. The first joint of the tarsus, or planta, of this leg is also used in the domestic economy of the insect to assist in the same object. In the domestic bee the under side of the posterior plantæ have a very peculiar structure, consisting of a series of ten transverse broad parallel lines of minute dense but short brushes, whichare used in the manipulations within the hive. Neither the Queen-bee nor the drone have this structure, and in the humble-bee and scopuliped bees the same joint is uniformly covered with this brush without its being separated into lines.
TheAbdomenof bees has many shapes, its form being elliptical, cylindrical, subcylindrical, clavate, conical or subconical, and sometimes semicircular, or concavo-convex. It consists of six imbricated plates, called segments, in the female, and of seven in the male; in the latter sex, in several genera, it takes beneath at its base and at its apex, as well as at the extremity of the latter, remarkable forms and armature. It is very variously clothed and coloured, and sometimes extremely gaily and elegantly so; these various markings often giving the insects their specific characteristics; the clothing of the under side of this segment of the body, likewise, furnishes subsidiary generic characters, especially in the artisan bees, in whom it takes the place of the posterior legs as a polliniferous organ. This is possibly because were the supply conveyedupontheir posterior legs it would be rubbed away as they entered the narrow apertures of their nests. Nature does nothing in vain, and there is evidently a purpose in this arrangement.
If we can trace peculiarities of structure to efficient reasons, differences of form may be rationally concluded as having their cause too, even if it elude our explanatory research. Although the reason of peculiar structure is not always obvious, it must exist, though undetected; as, for instance, why in some bees, as inMegachile,Osmia,Chelostoma,Anthidium, etc., the under side of the abdomen should be furnished densely with hairs to carry their provision of pollen home to their nest, when in otherbees, as inDasypoda,Panurgus,Eucera,Anthophora, etc. etc., it is conveyed upon the posterior legs, we do not know; we can only surmise that it is either to save the insect, in the former case, the labour of constructing a larger cylinder for nidification, so to prevent the possibility of its being rubbed off from the external surface of the legs, did these carry it, in entering the burrow, it being protected from this abrasion by being placed beneath the venter. In such insects the abdomen is usually truncated at its origin, or even hollowed within its base, thus to meet the projection of the metathorax, enabling it to draw itself closely up together, making the abdomen and metathorax, as it were, cohere. A different form of abdomen occurs in those bees which carry the pollen on their posterior legs. It is then more or less elliptical or lanceolate, which form permits the legs to be drawn up towards the metathorax within the space that kind of form furnishes, which, by this different but equivalent arrangement, meets the same object. The similarity of the adjustment of the abdomen to the metathorax to that ofMegachile, etc. inApisandBombus, by which insects the provision is also carried on the posterior legs, results from the totally different economy and habitation of the social bees, to which this structure is necessary for many purposes.
If we observe this same peculiarity of structure in the cuckoo, or parasitical bees, it is because we find resemblances where there are alliances. Thus, the male artisan bees, although not assisting in the labour of constructing the apartments, have similarly dilated mandibles to those of their females. So also, in the form of the abdomen, theNomadæare like theAndrenæandHalicti, upon which they are chiefly parasitical.MelectaresemblesAnthophora;Cælioxyshas the form ofMegachile, both in the hollowed base of the abdomen and the peculiar manner the latter has of raising its extremity,—something like aStaphylinus. Many other peculiarities of resemblance might be enumerated.
Having thus completed the description of the external anatomy of the bee desirable to be known for facilitating the comprehension of what I may have subsequently to say. I shall now refer to a few peculiarities of their manners, which could not be conveniently introduced elsewhere.
In their modes of flight bees vary considerably; some dart along in a direct line, with almost the velocity of lightning, visit a flower for an instant, and then dart off again with the same fleetness and vivacity, likeSaropodaandAnthophora; others leisurely visit every blossom, even upon a crowded plant, with patient assiduity, likeBombus; and some, either from fatigue, or heat, or intoxication, repose, like luxurious Sybarites, within the corolla of the flower. The males seem to flutter about in idle vagrancy, and may be often observed enjoying themselves upon some fragrant hedge-row. But the domestic bee and the humble-bee are the most sedulous in their avocation, and both cheering their labour with their seemingly self-satisfied and monotonous hum.
Bees, too, have a voice; but this voice does not proceed from their mouth, nor is it the result of air passed from the lungs through the larynx, and modulated by the tongue, teeth, and lips; for bees breathe through spiracles placed laterally along the several segments of the body, and their interior is aerified by tracheæ, which ramify variously through it; but their voice is produced by the vibration of the wings beating the air duringflight. Even as Linnæus constructed a floral clock to indicate the succession of hours by the expansion of the blossoms of flowers, so might a Beethoven or a Mendelssohn—the latter in the spirit of his philosophical ancestor—note down the several sounds of the hum of the many kinds of bees to the construction of a scale of harmonic proportions, whose Æolian tones, heard in the fitfulness of accidental reverberation amidst the solitudes of nature, repeatedly awaken in the mind of the entomologist the soothing sensation of a soft, voluptuous, but melancholy languor, or exhilarate him with the pleasing feeling of brisk liveliness and impatient energy.
It is rarely that a bee is seen to walk, although a humble-bee or hive bee may be seen crawling sometimes from flower to flower on the same footstalk, but they are never good pedestrians. They convey themselves upon the wing from blossom to blossom, and even on proceeding home they alight close to the aperture of their excavated nidus, to which an unerring instinct seems to guide them. There occasionally they will meet with the intrusive parasite, to whom some genera (Anthophora,Colletes) give immediate battle, and usually succeed in repulsing the interloper, who patiently awaits a more favourable opportunity to effect her object.
Bees are exceedingly susceptible of atmospheric changes; even the passage of a heavy cloud over the sun will drive them home; and if an easterly wind prevail, however fine the weather may otherwise be, they have a sort of rheumatic abhorrence of its influences, and abide at home, of which I have had sometimes woful experience in long unfruitful journeys.
The cause would seem to be the deficiency of electricity in the air, for if the air be charged, and a westerlywind blow, or there be a still sultriness with even an occasionally overcast sky, they are actively on the alert, and extremely vivacious. They are made so possibly by the operation of the influence upon their own system conjunctively with the intensity of its action upon the vegetable kingdom, and the secretions of the flowers both odorous and nectarian.
Bees do not seem to be very early risers, the influence of the sun being their great prompter, and until that grows with the progress of the morning they are not numerously abroad. Early sometimes in the afternoon some species wend homewards, but during the greatest heat of the day they are most actively on the alert. The numbers of individuals that are on the wing at the same time must be astounding, for the inhabitants of a single colony, where they may, perhaps, be called semi-gregarious, from nidificating collectively within a circumscribed space, can be computed by myriads. And then the multitude of such colonies within even a limited area! When we add to this the many species with the same productiveness! Yet who, in walking abroad, sees them but the experienced entomologist? When we consider the important function they exercise in the economy of nature, and that but for them, in the majority of instances, flowers would expand their beautiful blossoms in abortive sterility, we can but wonder at the wise and exuberant provision which forecasts the necessity and provides accordingly. But that even these should not superabound, there is a counterbalance in the numerousEnemiesto which they are exposed. The insectivorous animals, birds, among which there is one especially their arch-enemy—the bee-eater; those reptiles which can reach them; many insects in a varietyof ways, as the cuckoo-bees, whose foster-young starve the legitimate offspring by consuming its sustenance; and personal parasites, whose abnormal and eccentric structure required an Order to be established for their admission. Strange creatures! more like microscopic repetitions of antediluvian enormities than anything within the visible creation, and to whose remarkable peculiarities I shall have occasion to return. Amongst theDipteraandLepidopteraalso they have their enemies.
Bees are sometimes exceedingly pleasant to capture, for many of them emit the most agreeable scents; some a pungent and refreshing fragrance of lemons; others the rich odour of the sweetest-scented rose; and some a powerful perfume of balsamic fragrance and vigorous intensity. These have their set-off in others which yield a most offensive smell, to which that of garlic is pleasant, and assafœtida a nosegay. These odours must have some purpose in their economy, but what it may be has not been ascertained.
They present very frequently remarkable disparities of structure and appearance in the sexes, so much so that its infrequency is rather the exception than the rule, and nothing in many cases but practical experience can associate together the legitimate sexes. Differences of size are the simplest conditions of these distinctions, for they occur also in individuals of the same sex. Differences of colour, consisting in increased intensity in the males, are also usually easily recognized; but the relative length and structure of the antennæ is a more marked disparity, and the development is always in favour of the male. The differences in the compound eyes are conspicuous in our native genera only in thedrone, where they converge on the vertex, and throw the stemmata down upon the face. I have before alluded to special peculiarities in the legs when treating of those limbs. In the wings there are occasional differences, but so slight as not to require, in a general survey, special notice; but wherever they occur it is always in the male that the greatest extension of those limbs is found. The differences in the termination of the abdomen I have noticed above, and these sexual peculiarities in some genera are very marked. The spines which arm it inAnthidiumandOsmia, and its peculiar structure inChelostomawe can account for; but we have not the same clue to their uses inCælioxys, in which the action of the abdomen is upward, and not downward, as in the others.
The association of the legitimate partners of our native species has been to a great extent already accomplished and recorded; therefore, in this case, with the requisite guides to further instruction at hand, the commencing entomologist will find no obstruction, but may register the observations of his own experience to verify the discoveries of his predecessors.
It would seem from the facts that have been recorded, and the close investigations made, that in some instances the next year’s bee is already disclosed and in the imago state, in the autumn of the existing year, so that it is ready, upon the first genial weather in the spring, to work its way out of its nidus, and take its part in the duties it has to perform. Whether this be for the economy of the food to the larva, or the saving of labour to the parent in gathering it, or that it would be prejudicial for it to lie dormant in the pupa state during the winter is not known, but thus in many instances it is.Sometimes a late autumnal impregnation takes place, for the males of someAndrenæ,Halicti, andBombiare found abroad only late in the autumn, and then in fine and recently disclosed condition.
It is a singular circumstance in the history of some species, that where they abound one season, nidificating on a certain spot in profusion, the following year, perhaps, and the year succeeding that, they will not be seen at all, but yet again a further year, and there they are as innumerable as ever.
What may control this intermittent appearance it is impossible to conceive, all the conditions of the spot and its surroundings being the same. This I have found to be a peculiarity incidental to many of the aculeateHymenoptera. It occurs also in the flowering of many plants which blossom irregularly from season to season. It is a fact scarcely concordant with the observed rapidity of the disclosure of the larva from the egg, and the speedy growth, development, and transformation of the latter into the pupa and imago.
The wild bees appear to be of annual, or of even more restricted duration merely. Of this, however, we have no certainty. The conclusion is derived chiefly from the circumstance that, as they progressively come forth with the growth of the year, they, when first appearing, are in fine and unsoiled condition. There are evidently in some species two broods in the year; the one in the spring and the other autumnal. In bees without pubescence we have not the same guide. But humble-bees are reputed to have a longer life than of one year, and hive bees are said to survive several years, a duration of existence inconsistent with analogy, and which has been repeatedly and strongly denied.
In speaking of theantennæandpalpi, I have called them sensiferous organs. The organ necessarily implies the perception, or whatever it may be, conveyed to the sensorium through its means, this being the receptacle of the sensation or idea, the external organ communicates. It is thus that activity is given to a power of discrimination, and consequently of election or rejection by the creature. This sensorium, in the higher animals, is the brain; and in the lower, where the nervous system is very differently constituted, a ganglion, or knot of nervous substance. That this brain, or ganglion, is the power exercising the control, may not be admitted, although it is there that our research compulsively terminates. The power itself is essentially spiritual, acting through a material agent, and may be an efflux of this nervous mass. Whether it cease with the death of the organ, we have no means of knowing. That it may be in some way analogous in nature to the human mind, but to a limited extent, there is reason to surmise. This power, in its collective capacity, is calledInstinct. This instinct is a faculty whose clear comprehension and lucid definition seem impossible to our understanding. Its attributes are very various, and its operations are always all but perfect. It is an almost unerring guide to the creature exercising it, and is as fully developed on its awakening as is, and with it, the imago upon its transformation.
Although observation has thought to have detected that experience sometimes uses a selection of means, and thus occasionally modifies the rigid exercise of the faculty, by adapting itself to the force of circumstances, it, when so, evidently assumes a higher character than has been willingly accorded to it. This instinct teaches the justdisclosed bee, without other teaching than that of the intuitive faculty, where to find its food, and how to build its abode. It directs it to the satisfying its material needs, and instructs it to provide for its offspring, and to protect them whilst in their nidus; the impulse to which follows immediately upon the satisfaction of the sexual desire, to which it is the seal.
If it bememorythat guides the bee from its wide wanderings back to its home, this then becomes an attribute to the faculty. Instinct indicates to them their enemies, and the wrongs these may intend, and shows them how they may be repulsed or evaded. In some of its operations it seems to be of a more perfect capacity than the operative faculty of human intelligence.
The senses evidently possessed by our insects are sight, feeling, taste, and smell, but whether they hear we cannot know, although the antennæ have been supposed to be its organ, for the apparent responsiveness of these to loud and sudden sounds, may equally result from the agitations of the air these produce. Their possession of touch, taste, and smell, are implied from what has been observed.
They certainly exercise a will, evinced by their power of discrimination, which decides what is salutary and what is noxious; and the passions are exemplified in their revenge, their sexual love, and their affection for their offspring, the latter being exhibited in their unremitting labour and careful provision for them, although they are never to see them. If there be any precedence in the order of the relative quality and distinction of the bees, it will be shown in the degree of superiority with which this function is accomplished. The perfection of this function we see progressively maturing as it passesonwards from the merely burrowing-bee to the more complicated processes of the masons, carpenters, and upholsterers,—all solitary insects, and working each individually and separately to the accomplishment of its object. But we may certainly inquire where we shall intercalate the sagacity of the cuckoo-bees. A vast bound is immediately made from the artisan bees to the social bees with three sexes, which, as first shown in the humble-bee, works in small and rude communities, with dwellings of irregular construction. The next and most perfect grade is the metropolitan polity, accomplished architecture, laborious parsimony, indomitable perseverance, and well-organized subordination of the involuntary friend of man, the domestic bee. This insect has furnished Scriptural figures of exquisite sweetness, poetry with pleasing metaphors, morality with aphorisms, and the most elegant of the Latin poets with the subject of the supremest of his perfect Georgics.
That bees feel pain may be assumed from the evidence we have of their feeling pleasure, although instances are on record of insects surviving for months impaled; and they lose a limb, or even an antenna, without evincing much suffering, and I have seen a humble-bee crawling along on the ground with its abdomen entirely torn away.
In speaking of the antennæ above, as possibly the organs of hearing, I would wish to add, that they evidently possess some complex function, of which, not possessing any analogy, we cannot certainly conceive any notion. They are observed to be used as instruments of touch, and that too of the nicest discrimination. They seem to be extremely sensitive to the vibrations of sound and the undulations of air, and keenly appreciative ofatmospheric influences, of heat, of cold, and of electrical agitations. That they are important media in sexual communication must be assumed from their great differences of structure and size in the sexes, probably both as organs of scent and stimulation. I have often observed bees thrust their antennæ into flowers, one at the time, before they have entered the flower themselves, and in some insects, as in the Ichneumons, they are constantly in a state of vibration,—a tribe which, although of the same order, are remote in position from the bees, yet they may be instructively referred to by way of analogy in the discussion of the uses of an organ, whose functions so clearly follow its structure and position in the organization of the entire class of insects, that the analogy might be safely assumed in application to every family of the class, if observation could only correctly ascertain its uses in any one of them.
That it is of primary signification to the bees, is sufficiently shown by nature having furnished these insects with an apparatus designed solely to keep the antennæ clean, and which I have described above, when speaking of the structure of the anterior leg.
In the social tribes the antennæ are used as means of communication. The social ants, bees, and wasps may be often seen striking each other’s antennæ, and then they will each be observed to go off in directions different from that which they were pursuing. An extraordinary instance of this mode of communication once came under my own notice, having been called to observe it. There was a dead cricket in my kitchen, another issued from its hole, and in its ramblings came across this dead one; after walking round, and examining it with its antennæ and fore legs a short time, it started off. Shortly,either attracted by sound, or meeting it by accident, it came across a fellow; they plied their antennæ together, and the result was that both returned to their dead companion, and dragged him away to their burrowing-place,—an extraordinary instance of intercommunication which I can vouch for.
It would be curious to know if the means of communication thus evidently possessed by animals, extends beyond the social and gregarious tribes, and whether the faculty undergoes any change through differences of climate and locality, as man has done in the lapse of time. For man, notwithstanding the vastly divergent differences of race, may be obscurely tracked through the dim trail of the affiliation of languages to one common origin. But the complete identity of habit throughout the world of those genera which are native with us, would seem to affirm that they are as closely allied in every other particular, were we in a condition to make the investigation, and whence we may conclusively assume that they all had one central commencement.
That this mode of communication, and this exercise of the organ in the solitary tribes is limited to the season of their amours is very probable, and I apprehend that it is not exercised between individuals of distinct species. But that, at that period, their action is intensified may be presumed from the then greater activity of the males, who seem to have been called into existence only to fulfil that great object of nature, and which she associates invariably with gratification and pleasure. Even in plants it may be observed to be attended with something very analogous to animal enjoyment in the peculiar development at that period of an excessively energetic propulsion, which is the nearestapproach the vegetable kingdom makes to the higher phase of sensiferous life.
The clothing and colouring of bees are very various, but the gayest are the parasites, red and yellow, with their various tints, and white and cream-colour decorate them. The ordinary colour is deep brown, or chestnut, or black. Where the pubescence is not dense, they are often deeply punctured, and exhibit many metallic tinges. Many are thickly clothed with long hair, and this, especially in theBombiandApathi, is sometimes of bright gay colour, yellow, red, white, of a rich brown, or an intense black, sometimes in bands of different tints upon the same insect, and sometimes of one uniform hue.