The Sacred Beetle, and Others

by Jean-Henri Fabre

A minute’s digging with my pocket-trowel and the humble cabin is laid bare. The mother is often present, occupied in some trifling household duties before quitting the cell for good. In the middle of the room lies her work, the cradle of the germ and the ration of the coming larva. Its shape and size are those of a Sparrow’s egg; and I am here speaking of both Gymnopleuri, whose habits and labours are so much alike that I need not distinguish between them. Unless we found the mother beside it, we should be unable to tell whether the ovoid which we have dug up is the work of the smooth or of the pock-marked insect. At most, a slight advantage in size might point to the former; and even so this characteristic is far from trustworthy.

The egg-shape, with its two unequal ends, one large and round, the other more pointed, shaped like an elliptical nipple, or even drawn out into the neck of a pear, confirms [[121]]the conclusions with which we are already acquainted. An outline of this kind is not obtained by rolling, which is only reconcilable with a sphere. To get it, the mother must knead her lump of stuff. This may be already more or less round, as the result of the work done in the yard whence it came and of the subsequent carting, or it may still be shapeless, if the heap was near enough to allow of immediate storing. In short, once at home, she acts like the Sacred Beetle, and does modelling-work.

The material lends itself well to this. Taken from the most plastic stuff supplied by the Sheep, it is shaped as easily as clay. In this way the graceful, firm, polished ovoid is obtained, a work of art like the pear and as exquisite in its soft curve as a bird’s egg.

Where, inside it, is the insect’s germ? If we argued rightly when discussing the Sacred Beetle, if really the questions of ventilation and warmth demand that the egg be as near as possible to the surrounding atmosphere, while remaining protected by a rampart, it is evident that the egg must be installed at the small end of the ovoid, behind a thin defensive wall.

And this in fact is where it lies, lodged in a tiny hatching-chamber and wrapped on every side in a blanket of air, which is easily renewed through a slender partition and a matted plug. This position did not surprise me; from what the Sacred Beetle had already taught me I expected it. The point of my knife, this time no novice, went straight to the ovoid’s pointed teat and scratched. The egg appeared, magnificently confirming the argument which had at first been merely suspected, then dimly seen and finally changed into certainty by the recurrence of the fundamental facts under varying conditions. [[122]]

Scarabs and Gymnopleuri are modellers who were not educated in the same school; they differ in the outline of their masterpiece. With the same materials, the first manufacture pears, the second for the most part ovoids; and yet, despite this divergence, they both conform to the essential conditions demanded by the egg and by the grub. The grub wants provisions that are not liable to become prematurely dry. This condition is fulfilled, so far as may be, by giving the mass a round shape, which evaporates less quickly because of its smaller surface. The egg requires unrestricted air and the heat of the sun’s rays, conditions which are fulfilled in the one case by the pear with its neck and in the other by the ovoid with its pointed end.

Laid in June, the egg of either species of Gymnopleuri hatches in less than a week. The average is five or six days. Any one who has seen the larva of the Sacred Beetle knows, so far as essentials go, the larva of the two small pill-rollers. In each case it is a big-bellied grub, curved into a hook and carrying a hump or knapsack which contains a portion of the mighty digestive apparatus. The body is cut off slantwise at the back and forms a stercoral trowel, denoting habits similar to those of the Sacred Beetle’s larva.

We see repeated, in fact, the peculiarities described in the story of the big pill-roller. In the larval state, the Gymnopleuri also are great excreters, ever ready with mortar to make good the imperilled dwelling. They instantly repair the breaches which I make, either to observe them in the privacy of their home or to provoke their plastering-industry. They fill up the chinks with putty, solder the parts that become disjointed, mend the broken cell. When the nymphosis approaches, the mortar that [[123]]remains is expended in a layer of stucco, which reinforces and polishes the inner walls.

The same dangers give rise to the same defensive methods. Like the Sacred Beetles’, the shell of the Gymnopleuri is liable to crack. The free admission of air to the interior would have disastrous consequences, by drying the food, which must keep soft until the grub has attained its full growth. An intestine which is never empty and which displays unparalleled docility gets the threatened grub out of its trouble. There is no need to enlarge upon this point; the Sacred Beetle has told us all about it.

The insects reared in captivity tell me that, in the Gymnopleuri, the larva lasts seventeen to twenty-five days and the nymph fifteen to twenty. These figures are bound to vary, but within narrow limits. I shall therefore fix each period at approximately three weeks.