The Insect World: Being a Popular Account of the Orders of Insects

The cells which compose the nest, and which are to receive the larvae of the insect, are of an oval shape, and of a pale yellow or even of a blackish colour. Fig. 334 represents these cells. The wax of which they are composed has none of the qualities of that of hive bees, but is soft, sticky, and brownish.

When the mother humble bee — which at first was alone and built her house single-handed — has made a certain number of cells, she seeks for honey and pollen, and prepares a paste, which she deposits in the future cradles. She then lays six or seven eggs in each. The larvae which come from them live in common, at the same table, under the same tent. The cell is at first only the size of a pea; it soon becomes too narrow, splits and cracks, and requires to be enlarged and repaired many times, a work of which our industrious insects acquit themselves with a good deal of care and attention. Before passing into the pupa state each larva spins for itself a shell or cocoon of very fine white silk. It ceases to eat, remains at first

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Fig. 334. — Cells from a Humble Bee's nest.

rolled up, then expands itself little by little, and changes its skin after three days. It passes fifteen days in the pupa state in a quiescent condition. After the normal time has elapsed for it to remain in its ihiding-place, it delivers itself from its mummy-like covering, with the help of the mother or the workers. The humble bee then appears robust, and its body is covered with a greyish down.

When the successive hatchings have furnished to the mother the reinforcement she is waiting for, the workers she has raised occupy themselves in building new cells, and in raising the wall of enclosure Which is to protect the nest. This wall, formed of wax, starts from :he base, and raises itself, like a vertical rampart, from every point in ;he circumference. They then surmount this by the first roof, which s flat, supported by some pillars, and in which they have left one or ;wo irregular openings. The whole is finally protected by a hemi-

36o THE INSECT WORLD.

spherical covering of moss, made into a son of felt and lined with wax. Fig. 335 represents, in its entirety, a nest of ihis humble bee.

The workers also take their part in rearing the eggs. They bring the paste, which they slip into the cells to the larvae by a small hole, which is shut immediately afterwards. Later, ihey again give their

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f^'g- 335 -Nest of the Moss Humble Bee {Bovthis musiorum).

assistance in disengaging the pupae from their envelopes. In short, they make themselves generally useful; but they hove one bad fault; they are very fond of eating the eggs laid by the mother. They try! to seize them as she deposits them, or drag them from the cells, and suck their contents. And so the mother is obliged to be incessantly defending her eggs against the voracity of the workers, and to be con-

stantly on her guard, so as to be ready to drive away these marauders from cells newly filled. We owe to an English naturalist, Newport, the knowledge of another curious fact relating to the laying of humble bees, which is the expedient the females and the males have recourse to for hastening the hatching of the eggs. They place themselves, like fowls sitting on their eggs, over the cocoons containing the pupae almost hatched. By breathing quickly, these industrious insects raise the temperature of their bodies, and consequently that of the air in the cells. Thanks to this supplementary heat, the metamorphosis of the pupae is much hastened. Newport, by slipping miniature thermometers between the cocoons of the nymphs and the sitting humble bees, ascertained that the temperature of the latter was about 34*^ C, whilst the temperature of the cocoons left to themselves was only 27 S C.; that of the air in the rest of the nest being only from 21° to 24^ C. After many hours of incubation, at the same time natural and artificial, in which Art and Nature are so closely allied, after the sitting insects have many times relieved one another, the young humble bees come out of their cells. They are at first soft, greyish, moist, and very susceptible to cold. But after a few hours they become stronger, and the yellow and black bands with which their abdomens are surrounded begin to be marked out. The spring laying produces exclusively workers. The greatest abundance of eggs is laid in August and September. The laying of the female eggs begins in July; that of the males follows soon after.

Until autumn the humble bees are incessantly enlarging their nests, and multiplying their little pots of honey. Without accumu-lating a great stock of provisions, for which they have no occasion, they always keep in reserve a quantity of pollen and honey for their daily wants. The cells in which the honey is stored differ very much in shape. Some species of humble bees give them long and narrow necks; others, less recherche in their style of construction, simply make cylindrical vases. There are among the humble bees races of artists and races of simple builders; the one construct with taste, the other only seek the useful. During the day the humble bees cull honey from the flowers. At night they enter their home; but a certain number take the liberty of sleeping out. Surprised by the arrival of night in the bottom of the calyx of a sweetly-scented flower, they philosophically determine to sleep in the open air, lying on this perfumed bed, with the heaven as their canopy. The coupling of the humble bees takes place towards the end of

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September. It costs the males their life, as it does with the hive bees. The impregnated females do not lay till the following spring; it is they who, after the winter is passed, will become the mothers of new generations. They will take the reins of the family when the mother who founded the colony, the males, as also the workers, shall, according to the laws of Nature, have passed away. There are often, on the other hand, some workers which, born in the spring, become fruitful, and lay the same year, but only the eggs of males. These become a butt for the jealousy of the reigning mother, who pursues them with fury, and devours their eggs. These, however, have themselves cruel hearts. Animated by a profound jealousy, they dispute the occupancy of the cells savagely, so as to be able to lay a few eggs in them, which are no sooner laid than they are destroyed by their savage sisters. However, they never make use of their stings in any of these attacks. The humble bee population is peaceful, even in its combats. After the first cold weather in autumn, all these insects, as we have said, perish, except the pregnant females. These privileged depositaries of the race, spes altera dofnns, look for a place of retreat, and there sleep till the following spring. Then they wake up and found new colonies, which continue the race.

For a long while were confounded with the humble bees certain insects which have the same appearance, that is to say, a hairy body, with bands of various colours, but whose hind legs are adapted neither for gathering honey nor for building. These are the genus Psithynis: it was Lepelletier de Saint- Fargeau who discovered their true position. These are parasites, and only consist of males and fertile females, without workers. They lay their eggs in the nest of the humble bee. They are, indeed, so like their hosts, that they can introduce themselves into their dwellings without raising any suspicion. The humble bees admit them freely, and receive them as if they belonged to the family; so much so, indeed, that the poor humble bees themselves bring up the larvae of these impudent guests. In the Order Hymenoptera one meets with many examples of these sorts of parasites, which instal their progeny in the nest of another insect, as the cuckoo does in the nests of other birds.

Solitary Bees.

We have up till now found the insects of the great family of bees collected together in periectly organised societies. But there are a great number of species of this family which live alone. We will briefly mention the most interesting of them.

The females of the solitary bees are impregnated like those of the humble bees, and lay in spring, after having passed the winter

Figs. 336, 337, 338.— Anthophora parietina.

Fig. 339. — Carpenter Bee, Pupae, Eggs, Galleries, and Nests.

asleep. They build a. nest divided into cells, fill it with eggs, and with a honied paste shut it up, and die, without having seen their progeny hatched.

The Anthophoras (Figs. -^2)^^ 337, 338) resemble bees, but they are more hairy, and of greyish colour. Their nest, composed of earth tempered and agglutinated with their saliva, is made in the cracks of old walls or in the ground. It has the form of a twisted tube, and is divided, by partitions, into compartments, each of which is to receive

Fig. 340. — Mason Bee and Nest.

a larva. Each insect, when hatched, pierces its own wall, and profits by the hole of exit of the brother which preceded it.

These insects do not live together in societies. Indifferent neighbours, they do not lend each other mutual assistance. They have their parasites, the Meladas^ like the humble bees. These parasites are hairy, blackish insects, spotted with white, laying their eggs in the nests of the Anthophoras^ which permit them to do so, and, at the expense of their own progeny, bring up the intruder'slittle ones.

The Carpenter Bee, or Wood-piercer {Xylocopa), hollows out t

HYMENOPTERA.I

galleries in decayed wood, and builds in them cells placed "one over the other — a work often occupying many weeks. She then furnishes the bottom of the cell with pollen mixed up with honey, lays an egg in the middle of this paste, and closes the cell by a ceiling of sawdust agglutinated with saliva. On this ceiling she establishes a new cell, and so on, right up to the orifice, which she closes in the same

Fig. 341. — Interior of the Nest of the Mason Bee,

manner. Reaumur is astonished, with reason, at the admirable instinct which makes this provident mother determine the exact quantity of nourishment which will be necessary for its larva. When this has absorbed all its provisions, it alone quite fills up its cell, and changes into a pupa. It is worthy of remark, that the head of the young is always turned downwards, in such a way that it is by the bottom of its cell that it comes out. The bottom of the first is very near the surface of the wood, so that the insect it encloses has only a thin layer of wood to pierce through in order to set itself free. Each one of those which are born next has only to pierce the floor of its