This exclusiveness of the carnivorous larva seems all the more probable inasmuch as the larva reared on vegetable food refuses in any way to lend itself to a change of diet. However pressed by hunger, the caterpillar of the Spurge Hawk-moth, which browses on the tithymals, will allow itself to starve in front of a cabbage leaf which makes a peerless meal for the Pieris. Its stomach, burned by pungent spices, will find the Crucifera insipid and uneatable, though its piquancy is enhanced by essence of sulphur. The Pieris, on its part, takes good care not to touch the tithymals: they would endanger its life. The caterpillar of the Death's-head Hawk-moth requires the solanaceous narcotics, principally the potato, and will have nothing else. All that is not seasoned with solanin it abhors. And it is not only larvae whose food is strongly spiced with alkaloids and other poisonous substances that refuse any innovation in their food; the others, even those whose diet is least juicy, are invincibly uncompromising. Each has its plant or its group of plants, beyond which nothing is acceptable.
I remember a late frost which had nipped the buds of the mulberry-trees during the night, just when the first leaves were out. Next day there was great excitement among my neighbours: the Silk-worms had hatched and the food had suddenly failed. The farmers had to wait for the sun to repair the disaster; but how were they to keep the famishing new-born grubs alive for a few days? They knew me for an expert in plants; by collecting them as Iwalked through the fields I had earned the name of a medical herbalist.
With poppy-flowers I prepared an elixir which cleared the sight; with borage I obtained a syrup which was a sovran remedy for whooping-cough; Idistilled camomile; I extracted the essential oil from the wintergreen. In short, botany had won for me the reputation of a quack doctor. After all, that was something.
The housewives came in search of me from every point of the compass and with tears in their eyes explained the situation. What could they give their Silk-worms while waiting for the mulberry to sprout afresh? It was a serious matter, well worthy of commiseration. One was counting on her batch to buy a length of cloth for her daughter, who was on the point of getting married; another told me of her plans for a Pig to be fattened against the coming winter; all deplored the handful of crown-pieces which, hoarded in the hiding-place in the cupboard, would have afforded help in difficult times. And, full of their troubles, they unfolded, before my eyes, a scrap of flannel on which the vermin were swarming:
"Regardas, moussu! Venoun d'espeli; et ren per lour douna! Ah, pecaire!""Look, sir! The frost has come and we've nothing to give them! Oh, what a misfortune!"Poor people! What a harsh trade is yours: respectable above all others, but of all the most uncertain! You work yourselves to death; and, when you have almost reached your goal, a few hours of a cold night, which comes upon you suddenly, destroys your harvest. To help these afflicted ones seemed to me a very difficult thing. I tried, however, taking botany as my guide; it suggested to me, as substitutes for the mulberry, the members of closely-related families: the elm, the nettle-tree, the nettle, the pellitory.
Their nascent leaves, chopped small, were offered to the Silk-worms. Other and far less logical attempts were made, in accordance with the inspiration of the individuals. Nothing came of them. To the last specimen, the new-born Silk-worms died of hunger. My renown as a quack must have suffered somewhat from this check. Was it really my fault? No, it was the fault of the Silk-worm, which remained faithful to its mulberry leaf.
It was therefore in nearly the certainty of non-fulfilment that I made my first attempts at rearing carnivorous larvae with a quarry which did not conform with the customary regimen. For conscience' sake, more or less perfunctorily, I endeavoured to achieve something that seemed to me bound to end in pitiful failure. Only the Bembex-wasps, which are plentiful in the sand of the neighbouring hills, might still afford me, without too prolonged a search, a few subjects on which to experiment. The Tarsal Bembex furnished me with what I wanted: larvae young enough to have still before them a long period of feeding and yet sufficiently developed to endure the trials of a removal.
These larva are exhumed with all the consideration which their delicate skin demands; a number of head of game are likewise unearthed intact, having been recently brought by the mother. They consist of various Diptera, including some Anthrax-flies. (Cf. "The Life of the Fly": chapters 2 and 4.--Translator's Note.) An old sardine-box, containing a layer of sifted sand and divided into compartments by paper partitions, receives my charges, who are isolated one from another. These Fly-eaters I propose to turn into Grasshopper-eaters; for their Bembex-diet I intend to substitute the diet of a Sphex or a Tachytes. To save myself tedious errands devoted to provisioning the refectory, I accept what good fortune offers me at the very threshold of my door. A green Locustid, with a short sabre bent into a reaping-hook, Phaneroptera falcata, is ravaging the corollae of my petunias. Now is the time to indemnify myself for the damage which she has caused me. I pick her young, half to three-quarters of an inch in length;and I deprive her of movement, without more ado, by crushing her head. In this condition she is served up to the Bembex-larvae in place of their Flies.
If the reader has shared my convictions of failure, convictions based on very logical motives, he will now share my profound surprise. The impossible becomes possible, the senseless becomes reasonable and the expected becomes the opposite of the real. The dish served on the Bembeces'
