While our prolific lady is engaged in this employment, her court consists of from four to twelve attendants, which are disposed nearly in a circle, with their heads turned towards her. After laying from two to six eggs, she remains still, reposing for eight or nine minutes. During this interval the bees in her train redouble their attentions, licking her fondly with their tongues. Generally speaking, she lays only one egg in a cell; but when she is pressed, and there are not cells enough, from two to four have been found in one. In this case, as if they were aware of the consequences, the provident workers remove all but one. From an experiment of Huber's, it appears that the instinct of the queen invariably directs her to deposit worker eggs in worker cells; for when he confined one, during her course of laying worker eggs, where she could only come at male cells, she refused to oviposit in them; and trying in vain to make her escape, they at length dropped from her; upon which the workers devoured them. Retarded queens, however, lose this instinct, and often, though they lay only male eggs, oviposit in worker cells and even in royal ones. In this latter case the workers themselves act as if they suffered in their instinct from the imperfect state of their queen; for they feed these male larvæ with royal jelly, and treat them as they would a real queen. Though male eggs deposited in worker cells produce small males, their education in a royal cell with "royal dainties" adds nothing to their ordinary dimensions[186].
The swarming of bees is a very curious and interesting subject, to which, since a female is the sine quâ non on this occasion, I may very properly call your attention here. You will recollect that I said something upon the principle of emigrations, when I was amusing you with the history of ants[187]; but the object with them seems to be merely a change of station for one more convenient or less exposed to injury, and not to diminish a superabundant population. Whereas in the societies of the hive-bee, the latter is the general cause of emigrations, which invariably take place every year, if their numbers require it; if not, when the male eggs are laid, no royal cells are constructed, and no swarm is led forth. What might be the case with ants, were they confined to hives, we cannot say. Formicaries in general are capable of indefinite enlargement, therefore want of room does not cause emigration;—but bees being confined to a given space, which they possess not the means of enlarging,—to avoid the ill effects resulting from being too much crowded, when their population exceeds a certain limit, they must necessarily emigrate. Sometimes—for instance, when wasps have got into a hive—the bees will leave it, in order to fly from an inconvenience or enemy which they cannot otherwise avoid; but it does not very often happen that they wholly desert a hive.
Apiarists tell us that, in this country, the best season for swarming is from the middle of May to the middle of June; but swarms sometimes occur so early as the beginning of April, and as late as the middle of August[188]. The first swarm, as I before observed, is led by the reigning queen, and takes place when she is so much reduced in size, in consequence of the number of eggs she has laid, (for previously to oviposition her gravid body is so heavy that she can scarcely drag it along,) as to enable her to fly with ease. The most indubitable sign that a hive is preparing to swarm,—so says Reaumur,—is when on a sunny morning, the weather being favourable to their labours, few bees go out of a hive, from which on the preceding day they had issued in great numbers, and little pollen is collected. This circumstance, he observes, must be very embarrassing to one who attempts to explain all their proceedings upon principles purely mechanical. Does it not prove, he asks, that all the inhabitants of a hive, or almost all, are aware of a project that will not be put in execution before noon, or some hours later? For why should bees, who worked the day before with so much activity, cease their labours in a habitation which they are to quit at noon, were they not aware that they should soon abandon it[189]? The appearance of the males, and the clustering of the population at the mouth of the hive, (though this last is less to be relied upon, being often occasioned by extreme heat,) are also indications of the approach of this event. A good deal depends, however, on the warmth of the atmosphere and the state of the weather either to accelerate or retard it. Another sign is a general hum in the evening, which is continued even during the night,—all seems to be in a bustle, the greatest restlessness agitates the bees. Sometimes to hear this hum the ear must be placed close to the hive, when clear and sharp sounds may be distinguished, which appear to be produced by the vibration of the wings of a single bee. This hum by some has been gravely construed into an harangue of the queen to animate her subjects to the great undertaking which she now meditates—the founding of a new empire. There sometimes seem to happen suddenly amongst them, says Reaumur, events which put all the bees in motion, for which no account can be given. If you observe a hive with attention, you may often remain a long time and hear only a slight murmur, and then, all in a moment, a sonorous hum will be excited, and the workers, as if seized with a panic terror, may be seen quitting their various labours, and running off in different directions. At these moments if a young queen goes out, she will be followed by a numerous troop.
Huber has given a very lively and interesting account of the interior proceedings of the hive on this occasion. The queen, as soon as she began to exhibit signs of agitation, no longer laid her eggs with order as before, but irregularly, as if she did not know what she was about. She ran over the bees in her way; they in their turn struck her with their antennæ, and mounted upon her back; none offered her honey, but she helped herself to it from the cells in her path. The usual homage of a court attending round her was no longer paid. Those however that were excited by her motions followed her, rousing such as were still tranquil upon the combs. She soon had traversed the whole hive, when the agitation became general. The workers, now no longer attentive to the young brood, ran about in all directions; even those that returned from foraging, before the agitation was at its height, no sooner entered the hive than they participated in these tumultuous movements, and, neglecting to free themselves from the masses of pollen on their hind legs, ran wildly about. At length there was a general rush to the outlets of the hive, which the queen accompanied, and the swarm took place[190].
It is to be observed that this agitation, excited by the queen, increases the customary heat of the hive to a very high temperature, which the action of the sun augments till it becomes intolerable, and which often causes the bees accumulated near the mouth of the hive to perspire so copiously, that those near the bottom, who support the weight of the rest, appear drenched with the moisture. This intolerable heat determines the most irresolute to leave the hive. Immediately before the swarming, a louder hum than usual is heard, many bees take flight, and, if the queen be at their head, or soon follows them, in a moment the rest rise in crowds after her into the air, and the element is filled with bees as thick as the falling snow. The queen at first does not alight upon the branch on which the swarm fixes; but as soon as a group is formed and clustered, she joins it: after this it thickens more and more, all the bees that are in the air hastening to their companions and their queen, so as to form a living mass of animals supporting themselves upon each by the claws of their feet. Thus they sometimes are so concatenated, each bee suspending its legs to those of another, as to form living chaplets[191]. After this they soon become tranquil, and none are seen in the air. Before they are housed they often begin to construct a little comb on the branch on which they alight[192]. Sometimes it happens that two queens go out with the same swarm; and the result is, that the swarm at first divides into two bodies, one under each leader; but as one of these groups is generally much less numerous than the other, the smallest at last joins the largest, accompanied by the queen to whom they had attached themselves; and, when they are hived, this unfortunate candidate for empire falls sooner or later a victim to the jealousy of her rival. Till this great question is decided, the bees do not settle to their usual labours.[192] If no queen goes out with a swarm, they return to the hive from whence they came.
As in regular monarchies, so in this of the bees, the first-born is probably the fortunate candidate for the throne. She is usually the most active and vigorous; the most able to take flight; and in the best condition to lay eggs. Though the queen that is victorious, and mounts the throne, is not, as Virgil asserts, resplendent with gold and purple, and her rival hideous, slothful and unwieldy[193], yet some differences are observable; the successful candidate is usually redder and larger than the others; these last, upon dissection, appear to have no eggs ready for laying, while the former, which is a powerful recommendation, is usually full of them. Eggs are commonly found in the cells twenty-four hours after swarming, or at the latest two or three days.
You may think, perhaps, that the bees which emigrate from the parent hive are the youth of the colony; but this is not the case, for bees of all ages unite to form the swarms. The numbers of which they consist vary much. Reaumur calls 12,000 a moderate swarm; and he mentions one which amounted to more than three times that number (40,000). A swarm seldom or never takes place except when the sun shines and the air is calm. Sometimes, when every thing seems to prognosticate swarming, a cloud passing over the sun calms the agitation; and afterwards, upon his shining forth again, the tumult is renewed, keeps augmenting, and the swarm departs[194]. On this account the confinement of the queens, before related, is observed to be more protracted in bad weather.
The longest interval between the swarms is from seven to nine days, which usually is the space that intervenes between the first and the second. The next flies sooner, and the last sometimes departs the day after that which preceded it. Fifteen or eighteen days, in favourable weather, are usually sufficient for throwing the four swarms. The old queen, when she takes flight with the first swarm, leaves plenty of brood in the cells, which soon renew the population[195].
It is not without example, though it rarely happens, that a swarm conducted by the old queen increases so much in the space of three weeks as to send forth a new colony. Being already impregnated, she is in a condition to oviposit as soon as there are cells ready to receive her eggs: and an all-wise Providence has so ordered it, that at this time she lays only such as produce workers. And it is the first employment of her subjects to construct cells for this purpose[196]. The young queens that conduct the secondary swarms usually pair the day after they are settled in their new abode; when the indifference with which their subjects have hitherto treated them is exchanged for the usual respect and homage.
We may suppose that one motive with the bees for following the old queen, is their respect for her; but the reasons that induce them to follow the virgin queens, to whom they not only appear to manifest no attachment, but rather the reverse, seem less easy to be assigned. Probably the high temperature of the hive during these times of tumultuous agitation may be the principal cause that operates upon them. In a populous hive the thermometer commonly stands between 92° and 97°; but during the tumult that precedes swarming it rises above 104°, a heat intolerable to these animals[197]. This is M. Huber's opinion. Yet still, though a high temperature will well account for the departure of the swarm from the hive with a virgin queen, if there were really no attachment, (as he appears to think,) is it not extraordinary, that when this cause no longer operates upon them, they should agglomerate about her, as they always do, be unsettled and agitated without her, and quiet when she is with them? Is it not reasonable to suppose that the instinct which teaches them what is necessary for the preservation of their society,—at the same time that it shows them that without a queen that society cannot be preserved,—impells them in every case to the mode of treating her which will most effectually influence her conduct, and give it that direction which is most beneficial to the community?