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Why, for example, does the Philanthus, that slender wasp, which captures the honey-bee upon the blossoms in order to feed her larvae; why, before she carries her prey to her offspring, does she "outrage the dying insect," by squeezing its crop in order to empty it of honey, in which she appears to delight, and does indeed actually delight?
Presently a wild excitement ensues; the foster- mothers, "frightened, fierce, and restless," as though suddenly attacked by an incomprehensible insanity, conceive an aversion for the young; "the neuters extirpate the larvae and drag them out of the nest," and the drama of destruction draws to a close with "the final catastrophe; the infirm and the dying are dismembered, eviscerated, dissected in a heap in the catacombs by maggots, woodlice, and centipedes."
Thus I should explain a case which I heard of lately of Anthocera trifolii, abundant for years in one corner of a certain field, and only there; while there was just as much trefoil all round for its larvae as there was in the selected spot. I can, I say, only give hints: but they will suffice, I hope, to show the path of thought into which I want young naturalists to turn their minds.
Fabre has proved this: let the temperature suddenly fall twenty degrees: the eggs of Geotrupes and the larvae of the cockchafer or the rose-beetle endure such vicissitudes of temperature with impunity; contracted and stiffened into little masses of ice, but not destroyed, they revive in spring no less than the eel fry, the rotifers, or the tardigrades.
It is well known that the labors of the husbandman cause an excessive multiplication of all those species of insects whose larvae are cherished in the soil, and of all that infest the orchard and garden. The farm is capable of supporting insects just in proportion to its capacity for producing corn and fruit.
Finally the moth comes upon the scene, its larvae "attacking the dwelling itself; gnawing and destroying the joists and rafters, until all is reduced to a few pinches of dust and shreds of grey paper." What picturesque expressions he employs to depict, by means of some significant feature, the striking peculiarities of the insect physiognomy!
To paralyse without killing, "to deliver the prey to the larvae inert but living": that is the end to be attained; only the method varies according to the species of the hunter and the structure of the prey; thus the Cerceris, which attacks the coleoptera, and the Scolia, which preys upon the larvae of the rose-beetle, sting them only once and in a single place, because there is concentrated the mass of the motor ganglions.
Whether I had made a mistake or not previously to this I do not exactly know; but from this moment the larvae behaved in a most exemplary manner, especially when they became larger. They crawled over each other's backs without the least sign of spite or animosity, even when they were in sleep, in which case larvae are generally very sensitive and irritable, all were of a most pacific nature.
The larvae of this new hybrid, Roylei-Pernyi, contrary to what might have been expected, were much easier to rear than those of Roylei, and the cocoons obtained are far superior to those of Roylei, in size, weight, and richness of silk. The cocoon of my new hybrid has, like Roylei, an envelope, but there is no space between this envelope and the true cocoon inside.
From the twenty-five eggs he had twenty-three larvae hatched, which produced twenty-three fine cocoons. The same correspondent, with thirty-five eggs of Samia gloveri, obtained twenty cocoons. My other correspondents did not obtain any success in rearing these two species, as far as I know. Hybrid Roylei-Pernyi.
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