CHAPTER XVIII. THE INSECTS. A CAREFUL study and close observation of the various forms of insect life found either in, or on, or about the water is of the greatest interest to those who frequent the river-side for the purpose of fly-fishing, as it is chiefly by the successful imitation of many of those beautiful and minute denizens of the air and water that they are enabled to capture their prey. The difficulty of making an identical imitation of many of these is extremely great- it even may be doubted if an exact copy of the prototype could ever be produced. In almost all imitations of the natural insect the number of legs, and sometimes of the wings, are not in accordance with nature, and it must be borne in mind that trout are daily becoming more educated in their perceptive faculties. There is still, however, some chance for the angler. All fly-fishers know that trout and grayling will at times not only refuse the natural fly floating over them, and its artificial similar, but will at once greedily take some fancy fly. Do they take it for some juicy morsel, or do they at times follow the example of their cousins, the salmon and sea-trout, and take flies which have none of the characters and colours of those usually found on the river? That trout do take all kinds of things into their mouths as they float over them there is no question. We were watching some big trout at the tail of a mill-stream, and whilst doing so we lighted our pipe and threw the fusee into the water; as it sank, a great trout (at least 3 lbs. in weight) at once took it into his mouth. He soon rejected it, but had there been a hook attached to the fusee the trout would have had a bad time of it. We were one day fishing on the Kennet; there was a great rise of the paleblue dun, which the trout were taking eagerly. They would not look at the artificial similar, but at once, and greedily, took a small imitation of the March brown (which was not on the water); and, without moving ten yards, we landed five brace of fish, most of which we had seen rising at the blue dun. Insects pass through four metamorphoses during their life First, the Egg state, which is a non-active state. Second, the Larva state. This term of larva, from the Latin word signifying a mask, was given by Linnæus, because he considered that the real insect when in this form was masked; this name is also given to caterpillars, grubs, and maggots, which latter are generally called "gentils" or "gentles," a very ancient name. says: "Rewerd not thy sheep when ye take off his cote Tusser During this second state the larvæ are very voracious, cast their skins several times, and live for a long or short period- some only for a few days, others for weeks, months, or even years. When they cease eating they generally fix themselves in a secure place, their skin separates once more and discloses an oblong body, and they now enter the third (Pupa or Chrysalis) state, which may be divided into— (a.) That which differs but slightly from the larva state, but which has a kind of rudimentary wing. These are not only extremely active, but very voracious, as the dragon-flies, &c. (b.) That which is motionless and quite inactive, often surrounded with a hard case, as the cocoon or chrysalis of butterflies, moths, &c. This state may continue, as said above, for long or short periods, and then the fourth or last state is entered-viz., the Imago or perfect state-when the rudimentary wings become perfect, and the insect is able to take flight, and carry out the process of reproduction, &c. The Ephemerida appear to be an exception, having a state (Sub-Imago) between the third and fourth. The different orders of insects which will come under our notice are— We all know those little black, metallic, shiny fellows which are constantly gyrating in pools where the water is somewhat quiescent, and which are known commonly by the name of Whirligigs; the French call them Tourniquets, the scientific name being GYRINUS NATATOR. They appear GYRINUS NATATOR. to be always arranging a kind of skating quadrille, in and out and round about, and again joining in the centre. Just make your presence known by disturbing their pastime with the top of your rod. Ho, presto! Where are they? disappeared, for they are wonderful divers. Be careful, if you wish to examine them with your pocket-glass-and they are worth examining-to have your hand gloved, and even then you will not like it, for they emit a most un pleasant odour not easily forgotten. You will find that they have the antennæ very short; the two forelegs long and stretching forwards, other legs short and broad; the eyes are divided by horny processes, making one into two, as it were. They live in the mud in winter, deposit their eggs on the leaves of aquatic plants, and feed on small aquatic insects. The GREAT WATER-BEETLE (Dytiscus marginalis; from the Greek word dytes, a diver) is another familiar object coming at times to the surface of the water to breathe. He is a regular cannibal, with an enormous appetite, and will devour anything that comes in his way. It is generally supposed that the fish will not touch these beetles, but we are not so sure. At night they often leave the water and fly about, and perhaps as they return to their usual element, when their aerial flight is over, as they touch the surface of the water they may be gobbled up by the great trout, who are lurking about in those hours of darkness. They are about 1 inch in length, of a dark olive-colour. The throat and outer edge of the wing-case has a yellow margin. There are numerous species, varying in size. Another very common object is the WATER-BOATMAN OF BOAT-FLY (Noctonecta glaucus; order, Hemiptera; suborder, Heteroptera). It, too, is a voracious eater, and is extremely partial to tadpoles, and also its own species. It has the peculiarity of always swimming on its back, using as oars its hinder legs, which have a very powerful propelling power. It is about half an inch in length, generally of a greenish tinge, but varies much in colour, some being quite black. It very seldom flies, but it can do so, and very well. When diving it carries down a globule of air, for the purpose of respiration, in a hollow between the folded wings. One of this family (Corixa) is, however, often found in the stomachs of trout and grayling; but this differs somewhat in its mode of progression, as it does not swim on its back. THE WATER-BOATMAN. In the still eddies of streams, as well as on quiet pools and slow-running rivers and mill-heads, we constantly see that long-legged, brownish-looking, stick-like insect, the WATER-BUG (Ranatra linearis; order, Hemiptera). It seems to glide or skate, as it were, along the surface, and after three or four long slides comes to a full stop. It has two pairs of wings and three pairs of long legs. In Gilbert White's time it was supposed that this species was viviparous, and he gives a curious account of the mode of propagation; but the eggs have long been known to entymologists, and are deposited, or rather inserted, into the stems of aquatic plants, usually the club-rush, in which it is so deeply embedded by the long ovipositor of the insect as to be entirely hidden, the bristles alone projecting. These bristles, by preventing the edges of the plant stem from uniting, secure an exit for the larva when hatched. The females of this insect are much larger than the males. THE WATER-BUG. Many of us, no doubt, have come across that curious, black-looking insect, the DEVIL'S COACH-HORSE OF COCK |