The Reduvius personatus, called also Fly Bug, by Geoffroy, the old historian of the insects of the environs of Paris, is common enough in France. It keeps to the houses, and is found especially near ovens and chimney-pieces. It is about three-quarters of an inch in length, oblong, flat on its upper side, brownish, has horizontal hemelytra crossed over each other, and very fully developed wings, which serve for flight. Its head, narrow, supported by a well-defined neck, is provided with two composite and two simple eyes. It requires, no doubt, to see very clearly, as it flies by night. It should not be caught without great caution. If you desire to examine it closely, when, in the hottest part of the summer, it comes in the evening and flutters round the lights, you must be careful how you seize it, for it wounds. The wounds inflicted by it are very painful—more painful than those of the bee—and they immediately cause a numbness.
As the Reduvius kills different insects very rapidly, by piercing them with its long beak, it is probable that it secretes some kind of venom. But as yet the organ that produces this poison has not been discovered. However that may be, its beak is curved, and about the tenth of an inch long, the surface bristling with hairs. It is composed of three joints, and contains four stiff, lanceolate, and very pointed squamose hairs.
This insect often seeks its prey in places where spiders spin their webs. When they walk on, or are caught in, the spiders' webs, the spiders take care not to seize them, for they fear their beak. They prudently allow them to struggle about the nets, where they very soon die of hunger. The Reduvius is often seen, either a prisoner or dead, in the midst of a spider's web.
"This bug," says Charles de Geer, "has, in the pupal condition, or before its wings are developed, an appearance altogether hideous and revolting. One would take it, at the first glance, for one of the ugliest of spiders. That which above all renders it so disagreeable to the sight is that it is entirely covered, and, as it were, enveloped with a greyish matter, which is nothing else but the dust which one sees in the corners of badly-swept rooms, and which is generally mixed with sand and particles of wool, or silk, or other similar matters which come from furniture and clothes, rendering the legs of this insect thick and deformed, and giving to its whole body a very singular appearance."
What instincts! what habits! Under this borrowed costume, under this cloak, which is no part of itself, the insect, as it were, masked, has become twice its real size. What becomes of its disguise, and how does it manage to walk? Of what use to it is this dirty and grotesque fancy dress?
Let us listen to De Geer. "It walks as fast, when it likes, as other bugs; but generally its walk is slow, and it moves with measured steps. After having taken one step forward, it stops a while, and then takes another, leaving, at each movement, the opposite leg in repose; it goes on thus continually, step after step in succession, which gives it the appearance of walking as if by jerks, and in measure. It makes almost the same sort of movement with its antennæ, which it moves also at intervals and by jerks. All these movements have a more singular appearance than it is possible for us to describe."[23]
By means of this disguise, it can approach little animals, which become its prey, such as flies, spiders, bed bugs.
| Fig. 72.—Pupa of Reduvius personatus, covered with its cloak of dust (magnified). | Fig. 73.—Pupa of Reduvius personatus, denuded of its cloak of dust (magnified). |
To see what a curious appearance the Reduvius presents, one should take off its borrowed costume. Then you will observe an entirely different animal, and one which has nothing repulsive about it. With the exception of the hemelytra and wings, which it has not yet got, all its parts have the form which they are to have later, after the wings are developed.