TIPULA, the CRANE-FLY; a genus of insects belonging to the order of diptera. The mouth is a prolongation of the head; the upper-jaw is arched. They have two palpi, which are curved, and longer than the head. The proboscis is short, and bends inwards. Gmelin enumerates 123 species, of which 14 are British. They are divided into two families. 1. Those with wings displayed. 2. Those with wings incumbent, and which in form resemble a gnat.
This two-winged insect is often taken for the gnat, which it resembles, but has not its mischievous instinct, nor its murderous proboscis. The larger tipulæ go by the name of semipressæ, the small ones by that of caliciform; the latter, in fine summer evenings, flutter about the water-side in legions, through which a person may pass on his way unhurt. The shrill noise they make with their wings is not very discernible. Tipulæ, before they become inhabitants of the air, creep under the form of grubs. Those which turn to larger tipulæ dwell in holes of decayed willows, in the dampest places, where they change into chrysalids, and in that state have the faculty of breathing thro' two small curve horns; besides which they are endowed with progressive motion, but not retrogressive, being impeded by little spines placed on every ring of the abdomen. When the shroud is torn, the insect, prettily apparelled, escapes from his gloomy habitation by means of his wings, which often are variegated, and takes his pastime in the fields. Its long legs, and its wings, mutually assist each other when it either walks or flies. The larvæ and chrysalids of the little tipulæ are found in water. They are various in colour, form, and carriage; some being grey, others brown, and others red; some, like the polypus, furnished with a pair of arms; several with cylindrical tubes that perform the office of vent-holes. These swim with nimbleness; those never leave the holes they have dug for themselves in the banks of rivulets. Lastly, others make a filken cord that receives part of their body; but all of them, after a period, renounce their reptile and aquatic life, and receive wings from the hands of nature. Their frame is then so weak, that a touch is enough to crush them.
They are sometimes of a beautiful green, sometimes coal-black; and the most remarkable are those whose fore-legs, extraordinarily long, do not touch the ground, and are moveable like antennæ. In this state of perfection, the tipulæ being provided with proper organs, apply themselves to the propagation of the species. Those same poor insects, who in the state of larvæ have escaped the voraciousness of fishes, often become, in their progress through the air, a prey to equally merciless birds.