Social Life in the Insect World

by Jean-Henri Fabre

We have to wander for ages in the night of absurdity before we reach the radiant light of the truth. All our sciences witness to this fact; even the science of numbers. Try to add a column of Roman figures; you will abandon the task, stupefied by the confusion of symbols; and will recognise what a revolution was made in arithmetic by the discovery of the zero. Like the egg of Columbus, it was a very little thing, but it had to be thought of.

While hoping that the future will sink the unfortunate "fuller" in oblivion, we will use the term "pine chafer" between ourselves. Under that name no one can possibly mistake the insect in question, which frequents the pine-tree only.

It has a handsome and dignified appearance, rivalling that of Oryctes nasicornis. Its costume, if it has not the metallic splendour dear to the Scarabæi, the Buprestes and the rose-beetles, is at least unusually elegant. A black or chestnut background is thickly sown with capriciously shaped spots of white velvet; a fashion both modest and handsome.

The male bears at the end of his short antennæ a kind of plume consisting of seven large superimposed plates or leaves, which, opening and closing like the sticks of a fan, betray the emotions that possess him. At first sight it seems that this magnificent foliage must form a sense-organ of great perfection, capable of perceiving subtle odours, or almost inaudible vibrations of the air, or other phenomena to which our senses fail to respond; but the female warns us that we must not place too much reliance on such ideas; for although her maternal duties demand a degree of impressionability at least as great as that of the male, yet the plumes of her antennæ are extremely meagre, containing only six narrow leaves.

What then is the use of the enormous fan-like structure of the male antennæ? The seven-leaved apparatus is for the Pine-chafer what his long vibrating horns are to the Cerambyx and the panoply of the head to the Onthophagus and the forked antlers of the mandibles to the Stag-beetle. Each decks himself after his manner in these nuptial extravagances.

This handsome chafer appears towards the summer solstice, almost simultaneously with the first Cigales. The punctuality of its appearance gives it a place in the entomological calendar, which is no less punctual than that of the seasons. When the longest days come, those days which seem endless and gild the harvests, it never fails to hasten to its tree. The fires of St. John, reminiscences of the festivals of the Sun, which the children light in the village streets, are not more punctual in their date.

At this season, in the hours of twilight, the Pine-chafer comes every evening if the weather is fine, to visit the pine-trees in the garden. I follow its evolutions with my eyes. With a silent flight, not without spirit, the males especially wheel and wheel about, extending their great antennary plumes; they go to and fro, to and fro, a procession of flying shadows upon the pale blue of the sky in which the last light of day is dying. They settle, take flight again, and once more resume their busy rounds. What are they doing up there during the fortnight of their festival?

The answer is evident: they are courting their mates, and they continue to render their homage until the fall of night. In the morning both males and females commonly occupy the lower branches. They lie there isolated, motionless, indifferent to passing events. They do not avoid the hand about to seize them. Most of them are hanging by their hind legs and nibbling the pine-needles; they seem to be gently drowsing with the needles at their mouths. When twilight returns they resume their frolics.

To watch these frolics in the tops of the trees is hardly possible; let us try to observe them in captivity. Four pairs are collected in the morning and placed, with some twigs off the pine-tree, in a spacious; cage. The sight is hardly worth my attention; deprived of the possibility of flight, the insects cannot behave as in the open. At most I see a male from time to time approaching his beloved; he spreads out the leaves of his antennæ, and agitates them so that they shiver slightly; he is perhaps informing himself if he is welcome. Thereupon he puts on his finest airs and exhibits his attainments. It is a useless display; the female is motionless, as though insensible to these demonstrations. Captivity has sorrows that are hard to overcome. This was all that I was able to see. Mating, it appears, must take place during the later hours of the night, so that I missed the propitious moment.

One detail in particular interested me. The Pine-chafer emits a musical note. The female is as gifted as the male. Does the lover make use of his faculty as a means of seduction and appeal? Does the female answer the chirp of her innamorata by a similar chirp? That this may be so under normal conditions, amidst the foliage of the pines, is extremely probable; but I can make no assertion, as I have never heard anything of the kind either among the pines or in my laboratory.