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So from deep lakes the dread musquito springs,THE gnat, or musquito, culex pipiens. The larva of this insect lives chiefly in water, and the pupa moves with great agility. It is fished for by ducks; and, when it becomes a fly, is the food of the young of partridges, quails, sparrows, swallows, and other small birds. The females wound us, and leave a red point; and in India their bite is more venomous. The male has its antennæ and feelers feathered, and seldom bites or sucks blood; Lin. Syst. Nat.
Drinks the soft breeze, and dries his tender wings. CANTO I. l. 327.
It may be driven away by smoke, especially by that from inula helenium, elecampane; and by that of cannabis, hemp. Kalm. It is said that a light in a chamber will prevent their attack on sleeping persons.
The gnats of this country are produced in greater numbers in some years than others, and are then seen in swarms for many evenings near the lakes or rivers whence they arise; and, I suppose, emigrate to upland situations, where fewer of them are produced. About thirty years ago such a swarm was observed by Mr. Whitehurst for a day or two about the lofty tower of Derby church, as to give a suspicion of the fabric being on fire.
Many other kinds of flies have their origin in the water, as perhaps the whole class of neuroptera. Thus the libellula, dragon fly: the larva of which hurries amid the water, and is the cruel crocodile of aquatic insects. After they become flies, they prey principally on the class of insects termed lepidoptera, and diptera of Linneus. The ephemera is another of this order, which rises from the lakes in such quantities in some countries, that the rustics have carried cart-loads of them to manure their corn lands; the larva swims in the water: in its fly-state the pleasures of life are of short duration, as its marriage, {17} production of its progeny, and funeral, are often celebrated in one day. The phryganea is another fly of this order; the larva lies concealed under the water in moveable cylindrical tubes of their own making. In the fly-state they institute evening dances in the air in swarms, and are fished for by the swallows.
Many other flies, who do not leave their eggs in water, contrive to lay them in moist places, as the oestros bovis; the larvæ of which exist in the bodies of cattle, where they are nourished during the winter, and are occasionally extracted by a bird of the crow-kind called buphaga. These larvæ are also found in the stomachs of horses, whom they sometimes destroy; another species of them adhere to the anus of horses, and creep into the lowest bowel, and are called botts; and another species enters the frontal sinus of sheep, occasioning a vertigo called the turn. The musca pendula lives in stagnant water; the larva is suspended by a thread-form respiratory tube; of the musca chamæleon, the larva lives in fountains, and the fly occasionally walks upon the water. The musca vomitoria is produced in carcases; three of these flies consume the dead body of a horse as soon as a lion. Lin. Syst. Nat.