fourteen to seventeen days, the pupa works its way upward till the front part of its body sticks out of the soil. The fly then escapes. _Enemies_: Mole, shrews, wagtails, grasshopper warbler, rook, gulls. _Remedies_: When the maggots are very destructive in gardens they may be collected, preferably in wet weather, since they then leave the soil during the day. If they appear to an injurious extent on summer corn, the fields should be rolled in April (either with the ordinary or the spiked roller). At the time (June) when the crane flies swarm about the fields and meadows in flocks, thousands of individuals can easily be caught with a net. Family: =Muscæformes= (_Gnat Flies_). Gnats with relatively short legs, and antennæ which are in any case shorter than the body, and are usually quite short and cylindrical, possessing, however, six or more joints, while the antennæ of true flies usually have only three joints. The gnat flies form, as it were, the transition between the slender gnats with their long legs and antennæ, and the more thick-set flies, the legs and antennæ of which are short. Here belong the genera of =Shade Gnats= (_Sciara_, e.g. _Sciara Thomæ_, the larvæ of which often wander about in companies, as the so-called =Army Worm=), the =Sand Flies= (_Simulia_), and the =Hair Gnats= (_Bibio_, _e.g._ the =Garden Hair Gnat=, _Bibio hortulanus_, the larva of which gnaws the roots of plants, especially in humous garden soil). The =Sand Flies=, or =Mosquitoes= (_Simulia_), have thick-set bodies, short legs, and short nine or ten-jointed antennæ; they are from ¹⁄₂₅ to ⅕ of an inch long, and have a short but sharp proboscis, with which they suck up the flower juices which constitute their chief food. But the female also sucks the blood of human beings and animals, making herself exceedingly annoying in this way. Its larval state is passed through in stagnant water; its appearance is therefore local, and is especially favoured by damp summers. The mature sand flies are found from early spring or through the whole summer; several generations succeed one another in the same year. Sand flies often appear in swarms, containing thousands of individuals. Since the female eagerly creeps into the ears, noses, and corners of the eyes in horses and oxen, she is extremely annoying and even dangerous. Her bite produces a smarting sensation, and may cause actual boils to form in the skin. When a large swarm of sand flies settles on a herd of cattle or on some horses, these animals become maddened and furious; they often rush wildly round for so long that they fall down dead. _Simulia reptans_ is a common British form. _Remedies_: Compare what is said on p. 165, about gnats. Sand flies can usually be kept from horses’ ears by means of ear-caps. Family: =Tabanidæ= (_Gad Flies_). [Illustration: FIG. 114.—The Rain Breeze Fly (_Hæmatopota pluvialis_). ]