Bramble-Bees and Others

by Jean-Henri Fabre

I dig down to the full depth of the galleries and remove large lumps of earth which I take in my hands and break very carefully so as to examine all the parts that may contain cells. Halicti in the perfect state predominate, most of them still lodged in their unbroken chambers. Though they are not quite so numerous, there are also plenty of pupae. I collect them of every shade of colour, from dead-white, the sign of a recent transformation, to smoky-brown, the mark of an approaching metamorphosis. Larvae, in small quantities, complete the harvest. They are in the state of torpor that precedes the appearance of the pupa.

I prepare boxes with a bed of fresh, sifted earth to receive the larvae and the pupae, which I lodge each in a sort of half-cell formed by the imprint of my finger. I will await the transformation to decide to which sex they belong. As for the perfect insects, they are inspected, counted and at once released.

In the very unlikely supposition that the distribution of the sexes might vary in different parts of the colony, I make a second excavation, at a few yards' distance from the other. It supplies me with another collection both of perfect insects and of pupae and larvae.

When the metamorphosis of the laggards is completed, which does not take many days, I proceed to take a general census. It gives me two hundred and fifty Halicti. Well, in this number of Bees, collected in the burrow before any have emerged, I perceive none, absolutely none but females; or, to be mathematically accurate, I find just one male, one alone; and he is so small and feeble that he dies without quite succeeding in divesting himself of his nymphal bands. This solitary male is certainly accidental. A female population of two hundred and forty-nine Halicti implies other males than this abortion, or rather implies none at all. I therefore eliminate him as an accident of no value and conclude that, in the Cylindrical Halictus, the July generation consists of females only.

The building-operations start again in the second week of July. The galleries are restored and lengthened; new cells are fashioned and the old ones repaired. Follow the provisioning, the laying of the eggs, the closing of the cells; and, before July is over, there is solitude again. Let me also say that, during the building-period, not a male appears in sight, a fact which adds further proof to that already supplied by my excavations.

With the high temperature of this time of the year, the development of the larvae makes rapid progress: a month is sufficient for the various stages of the metamorphosis. On the 24th of August there are once more signs of life above the burrows of the Cylindrical Halictus, but under very different conditions. For the first time, both sexes are present. Males, so easily recognized by their black livery and their slim abdomen adorned with a red ring, hover backwards and forwards, almost level with the ground. They fuss about from burrow to burrow. A few rare females come out for a moment and then go in again.

I proceed to make an excavation with my spade; I gather indiscriminately whatever I come across. Larvae are very scarce; pupae abound, as do perfect insects. The list of my captures amounts to eighty males and fifty-eight females. The males, therefore, hitherto impossible to discover, either on the flowers around or in the neighbourhood of the burrows, could be picked up to-day by the hundred, if I wished. They outnumber the females by about four to three; they are also further developed, in accordance with the general rule, for most of the backward pupae give me only females.

Once the two sexes had appeared, I expected a third generation that would spend the winter in the larval state and recommence in May the annual cycle which I have just described. My anticipation proved to be at fault. Throughout September, when the sun beats upon the burrows, I see the males flitting in great numbers from one shaft to the other. Sometimes a female appears, returning from the fields, but with no pollen on her legs. She seeks her gallery, finds it, dives down and disappears.

The males, as though indifferent to her arrival, offer her no welcome, do not harass her with their amorous pursuits; they continue to visit the doors of the burrows with a winding and oscillating flight. For two months, I follow their evolutions. If they set foot on earth, it is to descend forthwith into some gallery that suits them.

It is not uncommon to see several of them on the threshold of the same burrow. Then each awaits his turn to enter; they are as peaceable in their relations as the females who are joint owners of a burrow. At other times, one wants to go in as a second is coming out. This sudden encounter produces no strife. The one leaving the hole withdraws a little to one side to make enough room for two; the other slips past as best he can. These peaceful meetings are all the more striking when we consider the usual rivalry between males of the same species.