The Hunting Wasps

by Jean-Henri Fabre

We wonder if the Ammophilæ whom we find occupied with their burrows in the first days of April are really insects of that year, that is to say, if these spring workers completed their metamorphosis and left their cocoons during the previous three months. The general rule is for the Digger to become a perfect insect, to quit her subterranean dwelling and to busy herself with her larvæ all in one season. Most of the Predatory Wasps leave the galleries where they [[218]]lived as larvæ in the months of June and July and display their talents as miners and hunters in the following months of August, September and October.

Does a similar law apply to the Hairy Ammophila? Does the same season witness the insect’s final transformation and its labours? It is very doubtful, for the Wasp occupied on the work of the burrow at the end of March would in that case have to complete her metamorphosis and to break out of her cocoon during the winter, or at latest in February. The severity of the climate at this period does not allow us to accept such a conclusion. It is not at a time when the bleak mistral howls for a fortnight without intermission and freezes the ground hard, it is not at a time when snowstorms follow close upon that icy blast, that the delicate transformations of the nymphosis are able to take place or the insect to dream of abandoning the shelter of its cocoon. It needs the warm moisture of the earth under the summer sun before it can leave its cell.

If I knew the exact period at which the Hairy Ammophila emerges from her native burrow, this would help me greatly; but, to my intense regret, I do not know it. My notes, collected day by day, with the lack of order inevitable in a type of research that is constantly [[219]]subject to the hazards of the unforeseen, are silent on this point, of which I clearly perceive the importance now that I am trying to arrange my materials in order to write these lines. I find the Sandy Ammophila mentioned as hatching on the 5th of June and the Silvery Ammophila on the 20th of that month; but my records contain not a word that relates to the hatching of the Hairy Ammophila. It is a detail which, by an oversight, has never been cleared up. The dates given for the other two species come under the general law, which lays down that the perfect insect shall appear during the hot season. I fix the same period, by analogy, as that for the Hairy Ammophila’s emergence from the cocoon.

Then whence come the Ammophilæ whom we see working at their burrows at the end of March and in April? We are driven to the conclusion that these Wasps belong not to the present but to the previous year; that they left their cells at the usual time, in June and July, got through the winter and began to make their nests as soon as the spring came. In a word, they are hibernating insects. And this conclusion is fully borne out by experiment.

If we will but search patiently in the perpendicular banks of earth or sand facing due south, especially those in which generations of [[220]]different honey-gathering Bees have succeeded one another year after year and riddled the wall with a labyrinth of tunnels until it looks like an enormous sponge, we are almost sure, in midwinter, to find the Hairy Ammophila snugly ensconced in the shelters provided by the sunny bank, alone or in groups of three or four, idly awaiting the arrival of the fine weather. I have been able to give myself as often as I wished this little treat of renewing my acquaintance, amid the gloom and cold of winter, with the pretty Wasp who enlivens the greensward beside the paths at the first notes of the Bunting and the Cricket. When there is no wind and the sun is shining brightly, the warmth-loving insect comes to its threshold to bask luxuriously in the hottest rays, or it will even timidly venture outside and, step by step, stroll over the surface of the spongy bank, polishing its wings as it goes. Even so does the little Grey Lizard behave, when the sun once more begins to warm the old wall that represents his native land.

But vain would be our search in winter, even in the most sheltered refuges, for a Cerceris, Sphex, Philanthus, Bembex or other Wasp with carnivorous grubs. All died after their autumnal labours and their race is not represented, in the cold season, save by the [[221]]larvæ slumbering in their cells. It is, then, by a most rare exception that the Hairy Ammophila, hatched in the hot season, spends the following winter in some warm shelter; and this is the reason why she appears so very early in the spring.

With these data to go upon, let us try to explain the cluster of Ammophilæ which I observed on the ridges of Mont Ventoux. What could these numerous Wasps have been doing, heaped up under their stone? Were they preparing to take up their winter quarters there and, slumbering under cover, to await the season favourable to their work? Everything tends to show that this is improbable. It is not in August, at the hottest time of year, that an animal is overcome with its winter drowsiness. Nor is it any use to suggest the want of food, of honeyed juices sucked from the flowers. The September showers are at hand; and vegetation, suspended for a moment by the heat of the dog-days, will gather fresh vigour and cover the fields with blossoms almost as diverse as those of spring. This season of revelry for the majority of Wasps and Bees could never be a period of torpor for the Hairy Ammophila.

And then have we any right to imagine that the heights of Ventoux, swept by the gusts of [[222]]the mistral, which sometimes uproots both beech and pine; that crests where the north wind sends the snow-flakes whirling for six months in succession; that peaks wrapped for the best part of the year in cold cloud-fogs, can be adopted as a winter refuge by an insect enamoured of the sun? One might as well suggest that it should hibernate among the ice-floes of the North Cape. No, it is not here that the Hairy Ammophila can spend the cold season. The group which I observed was only passing through. At the first hint of rain, a hint that escaped us but could not escape the insect, which is so highly sensitive to the atmospheric variations, the band of travellers had taken shelter under a stone, waiting for the rain to stop before resuming their flight. Whence did they come? Whither were they bent?

In this same month of August, and still more in September, we are visited, in our warm, olive-clad regions, by caravans of little birds of passage descending by easy stages from the countries where they have wooed and loved, countries cooler, more thickly wooded, less wild than ours, where they have reared their broods. They arrive almost on a fixed day, in an unvarying order, as though guided by the dates of a calendar known only to themselves. They [[223]]sojourn for some time in our plains, a halting-place rich in insects, which form the exclusive fare of most of them; they ransack every clod in our fields, where the ploughshare by now has laid bare in the furrows a multitude of grubs, their special delight; thanks to this diet, they soon put on a fine cushion of fat, a storehouse of reserve provisions for the coming exertions; and at last, supplied with this viaticum, they continue their southward flight, making for the winterless lands where insects are never lacking: Spain, Southern Italy, the Mediterranean islands and Africa. This is the season for brave sport with the gun and for dainty roasts of small birds.

The first to arrive is the Shore-lark, or, as he is called in these parts, the Crèou. August is hardly here before we see him exploring the pebbly fields, in search of the little seeds of setaria, an ill weed that overruns our tilled soil. At the least alarm he flies away with a harsh clattering in his throat which is not badly represented by his Provençal name. He is soon followed by the Whin-chat, who preys placidly on small Weevils, Locusts, and Ants in the old lucern-fields. With him begins the long line of small winged things, the glory of the spit. It is continued, when September comes, by the most famous of them, the Common [[224]]Wheat-ear, or White-tail, extolled by all who are able to appreciate his exalted qualities. No Beccafico of the Roman epicures, immortalized in Martial’s epigrams, ever equalled the exquisite, scented ball of fat that is the Wheat-ear, grown shamefully stout on gluttonous living. He is an unbridled devourer of every kind of insect. The notes which I have taken as a sportsman and naturalist bear witness to the contents of his gizzard. It includes the whole little world of the fallow fields: grubs and Weevils of every species, Locusts, Tortoise-beetles, Golden Apple-beetles, Crickets, Earwigs, Ants, Spiders, Wood-lice, Snails, Millipedes, and ever so many others. And, as a change from this full-flavoured diet, there are grapes, blackberries and dogberries. Such is the bill of fare for which the Wheat-ear is ever in search, as he flies from clod to clod, with the white feathers of his outspread tail giving him that fictitious look of a Butterfly on the wing. And Heaven knows what prodigies of plumpness he is able to achieve.