It is principally in hot countries that the cockroaches do the greatest damage. In the Antilles, of which they are the pest, it is affirmed that in one single night they can bore holes through trunks, through cases, and through bags, and destroy objects which were supposed to be in perfect safety. Sometimes the walls, the floors, the beds, the tables, everything, in short, is infested by them, and it is impossible to find a way of preserving the food from their repulsive touch. One can, however, partially succeed in destroying them by the aid of insect powders. They have, however, natural enemies. Poultry and owls are very fond of them. A species of wasp, Chlorion compressum, lays up a stock of cockroaches, which it previously renders insensible, for its larvæ. Many species of Chalcidiæ, a family of Hymenoptera, also live on the eggs of these Orthoptera. There are also among the cockroaches certain brightly-coloured exotic species. These colours show that they do not avoid the light. We will mention as examples the Brachycola robusta and the species of Corydia.
The Mantidæ are pretty insects, of very different habits from the preceding. They alone of the Orthoptera are carnivorous. They eat live insects, seizing their prey as it passes by them. They rest generally on shrubs, remaining for hours together perfectly motionless, the better to deceive other insects which are to become their victims.
It is this fixed and as it were meditative attitude which has gained for them the name of Mantis, derived from the Greek word μαντις, or "diviner," as it was imagined that in this attitude they interrogated the future. The manner in which they hold their long front legs, raised like arms to Heaven, has also contributed to make this superstitious notion believed, and sufficiently explains the names given to divers species of Mantidæ; such as Nun, Saint, Preacher, Suppliant, Mendicant, &c. Caillaud, a traveller, tells us that in Central Africa a Mantis is an object of worship. According to Sparmann, another species is worshipped by the Hottentots. If by chance a Mantis should settle on a person, this person is considered by them to have received a particular favour from heaven, and from that moment takes rank among the saints!
In France the country people believe that these insects point out the way to travellers. Mouffet, a naturalist of the seventeenth century, says on this subject, in a description of the Mantis:—"This little creature is considered of so divine a nature, that to a child who asks it its way, it points it out by stretching out one of its legs, and rarely or never makes a mistake."
In the eyes of the Languedoc peasants the Mantis religiosa is almost sacred. They call it Prega-Diou (Prie-Dieu), and believe firmly that it performs its devotions—its attitude, when it is on the watch for its prey, resembling that of prayer. Settled on the ground, it raises its head and thorax, clasps together the joints of its front legs, and remains thus motionless for hours together. But only let an imprudent fly come within reach of our devotee, and you will see it stealthily approach it, like a cat who is watching a mouse, and with so much precaution that you can scarcely see that it is moving. Then, all of a sudden, as quick as lightning, it seizes its victim between its legs, provided with sharp spines, which cross each other, conveys it to its mouth, and devours it. Our make-believe Nun, Preacher, our Prega-Diou, is nothing better than a patient watcher and pitiless destroyer. The Mantis religiosa ([Fig. 302]), common enough in the south of France, comes as far north as the environs of Fontainebleau. The Mantis oratoria, rather smaller, is less commonly met with.
These elegant insects are remarkable for their long slim bodies, their large wings, and their colours, which are generally very bright. In some species their green or yellowish elytra look so exactly like the leaves of trees that one can hardly help taking them for such.
The Mantis lays its eggs at the end of summer, in rounded, very fragile shells, attached to the branches of trees; they do not hatch till the following summer. The larvæ undergo several successive moultings. Nothing equals the ferocity of these Orthoptera. If two of them are shut up together, they engage in a desperate combat; they deal each other blows with their front legs, and do not leave off fencing until the stronger of the two has succeeded in eating off the other's head. From their very birth, the larvæ attack each other. The male being smaller than the female, is often its victim.
Kirby tells us that in China the children procure them as in France they do cockchafers, and shut them up in bamboo cages, to enjoy the exciting spectacle of their combats.
