The largest of the Acridians in our part of the country, the Grey Locust (Pachytylus cinerescens, Fabr.), rivals the African Locusts in size, without possessing their calamitous habits. He is peace-loving and temperate and above reproach where the fruits of the earth are concerned. From him we obtain a little information which is easily verified by observing the insect in captivity.
The eggs are laid about the end of April, a few days after the pairing, which lasts [[384]]some little while. The female is armed at the tip of the abdomen—as, in varying degrees, are the other Locust mothers—with four short excavators, arranged in pairs and shaped like a hooked finger-nail. In the upper pair, which are larger, these hooks are turned upwards; in the lower and smaller pair, they are turned downwards. They form a sort of claw and are hard and black at the point; also they are scooped out slightly, like a spoon, on their concave surface. These are the pick-axes, the trepans, the boring-tools.
The mother bends her long abdomen perpendicularly to the line of the body. With her four trepans she bites into the soil, lifting the dry earth a little; then, with a very slow movement, she pushes down her abdomen, making no apparent effort, displaying no excitement that would reveal the difficulty of the task.
The insect is motionless and contemplative. The boring-implement could not work more quietly if it were sinking into soft mould. It might all be happening in butter; and yet what the bore traverses is caked, unyielding earth.
It would be interesting, if it were only possible, [[385]]to see the perforating-tool, the four gimlets, at work. Unfortunately, things happen in the mysteries of the earth. No rubbish rises to the surface; nothing denotes the underground labour. Little by little the abdomen sinks softly in, as our finger would sink into a lump of soft clay. The four trepans must open the passage, crumbling the earth into dust which is thrust back sideways by the abdomen and packed as with a gardener’s dibble.
The best site for laying the eggs is not always found at the first endeavour. I have seen the mother drive her abdomen right in and make five wells one after the other before finding a suitable place. The pits recognized as defective are abandoned as soon as bored. They are vertical, cylindrical holes, of the diameter of a thick lead-pencil and astonishingly neat. No wimble would produce cleaner work. Their length is that of the insect’s abdomen, distended as far as the extension of the segments allows.
At the sixth attempt, the spot is recognized as propitious. The laying thereupon takes place, but nothing outside betrays the fact, so motionless does the mother seem, with her abdomen immersed up to the hilt, which [[386]]causes the long wings lying on the ground to rumple and open out. The operation lasts for a good hour.
At last the abdomen rises, little by little. It is now near the surface, in a favourable position for observation. The valves are in continual movement, whipping a mucus which sets in milk-white foam. It is very similar to the work done by the Mantis when enveloping her eggs in froth.
The foamy matter forms a nipple at the entrance to the well, a knob which stands well up and attracts the eye by the whiteness of its colour against the grey background of the soil. It is soft and sticky, but hardens pretty soon. When this closing button is finished, the mother moves away and troubles no more about her eggs, of which she lays a fresh batch elsewhere after a few days have intervened.
At other times, the terminal foamy paste does not reach the surface; it stops some way down and, before long, is covered with the sand that slips from the margin. There is then nothing outside to mark the place where the eggs were laid.