THE WHITE-FACED DECTICUS
The Greek word dectikos means biting, fond of biting. The Decticus is well named. It is eminently an insect given to biting
I find, when the Decticus is imprisoned in my menagerie, that any fresh meat tasting of Locust or Grasshopper suits his needs. The blue-winged Locust is the most frequent victim. As soon as the food is introduced into the cage there is an uproar, especially if the Dectici are hungry. They stamp about, and dart forward clumsily, being hampered by their long shanks. Some of the Locusts are caught at once, but others with desperate bounds rush to the top of the cage, and there hang on out of the reach of the Grasshopper, who is too stout to climb so high. But they have only postponed their fate. Either because they are tired, or because they are tempted by the green stuff below, they will come down, and the Dectici will be after them immediately.
This Grasshopper, though his intellect is dull, possesses the art of scientific killing of which we have seen instances elsewhere. He always spears his prey in the neck, and, to make it helpless as quickly as possible, begins by biting the nerves that enable it to move. It is a very wise method, for the Locust is hard to kill. Even when beheaded he goes on hopping. I have seen some who, though half-eaten, kicked out so desperately that they succeeded in escaping. [[131]]
With his weakness for Locusts, and also for certain seeds that are harmful to unripe corn, these Grasshoppers might be of some service to agriculture if only there were more of them. But nowadays his assistance in preserving the fruits of the earth is very feeble. His chief interest in our eyes is the fact that he is a memorial of the remotest times. He gives us a vague glimpse of habits now out of use.
It was thanks to the Decticus that I first learnt one or two things about young Grasshoppers.
Instead of packing their eggs in casks of hardened foam, like the Locust and the Mantis, or laying them in a twig like the Cicada, Grasshoppers plant them like seeds in the earth.
The mother Decticus has a tool at the end of her body with which she scrapes out a little hole in the soil. In this hole she lays a certain number of eggs, then loosens the dust round the side of the hole and rams it down with her tool, very much as we should pack the earth in a hole with a stick. In this way she covers up the well, and then sweeps and smooths the ground above it.
She then goes for a little walk in the neighbourhood, by way of recreation. Soon she comes back to the place where she has already laid her eggs, and, very near the original spot, which she recognises quite well, begins the [[132]]work afresh. If I watch her for an hour I see her go through this whole performance, including the short stroll in the neighbourhood, no less than five times. The points where she lays the eggs are always very close together.
When everything is finished I examine the little pits. The eggs lie singly, without any cell or sheath to protect them. There are about sixty of them altogether, pale lilac-grey in colour, and shaped like a shuttle.