FLY 295 larger than the blow fly, is ovo-viviparous ; it drops the living larvae on dead and decaying animal matter, and these active little scaven- gers commence at once their work of purifi- cation. A single female will produce about 20,000 young, which have been ascertained by Redi to increase in weight nearly 200-fold in 24 hours; Reaumur found the assemblage of embryo flies in this insect to be coiled like a watch spring, about 2 in. long when un- rolled ; the larvae arrive at maturity in succes- sion, and the mother as usual dies soon after the brood is hatched. This European species is black, with lighter stripes on the shoulders, and grayish black abdomen checkered with lighter squares. Another species of Europe is the S. mortuorum (Linn.), five or six lines long, with a golden head, grayish black thorax, steel-blue abdomen, and white wing scales. Both of these sometimes deposit their young on wounds and ill-conditioned ulcers of the living human body. The largest American species is the 8. Georgina (Wiedemann), the females of which are about half an inch long ; the face is silvery white, with a black spot between the copper-colored eyes ; the thorax light gray, with seven black stripes ; the hind body, conical and satiny, is checkered -with black and white ; they appear about the end of June, and continue till after the middle of August. In this genus the bristles on the an- tennaa are plumose. The dung fly (scatophaga stercoraria, Meig.), of a yellowish olive color, deposits its eggs in soft dung; at the upper end they have two divergent processes which prevent their sinking too far into the nidus. The S. furcata (Harris) of the United States has the same habits, and has been erroneously charged with producing the potato rot, simply because the larvae are found upon the stalks of this plant, developed from eggs laid in the sur- rounding manure. The males are yellow, with hairy body and legs, and long narrow wings, and are about half as large as a honey bee ; the females are smaller, less hairy, and olive-col- ored ; both young and adult insects live upon dung, and do not injure plants. The stable fly (stomoxys calcitram, Meig.) is a well known tormentor of animals and man, whose skin it perforates by a painful bite in sultry weather and just before rains ; it resembles very closely the house fly, except that the antennae are feathered, the proboscis very long and slender, and the size smaller ; it attacks the legs, pierc- ing through thick stockings and the thickest hair, returning to the attack as soon as driven away ; it is solitary, not social like the house fly, and seldom enters houses unless driven in by bad weather ; it is most abundant in August and September, when it is a great pest to horses and cattle ; it is about one third of an inch long, and lays its eggs in dung, in which the young are hatched and undergo their transfor- mations. The cheese fly (piophila casei, Fal- len.) is only /$ of an inch long, shining black, with transparent wings and yellowish hind By its long ovipositor it penetrates the cracks of cheese, and deposits about 250 eggs, which are developed in a few days into mag- gots or skippers ; these larvae have two horny Cheese Fly (Piophila casei). hooked mandibles, which they use for digging into the cheese, and for locomotion instead of feet. This larva leaps 20 or 30 times its own Larva of Piophila casei. length, first erecting itself on the tail, then bending into a circle and seizing the skin near the tail with its hooked jaws, and finally pro- jecting itself forward by suddenly throwing itself into a straight line. The droppings and decay caused by these larvae give a flavor to old cheese which is much relished by epicures. The wine fly, living in old casks and bottles, is also a piophila. There are several species of flower flies, of the genus anthomyia, of small size and feeble flight, which sport in the air in swarms like gnats, and which in the larva state are very injurious to vegetation ; some of these maggots are like those of common flies, others are fringed on the sides with hair. The A. ceparum (Meig.), of an ash-gray color, with Onion Fly (Anthomyia ceparum). 1. Fly. 2. Larva. 8. Pupa. black dorsal stripes, and about half the size of the house fly, lays its eggs on the leaves of the onion close to the earth ; its smooth white lar- vae bore into the bulb, and entirely destroy it. The A. IrassicoB and A. lactucarum are equally destructive to the cabbage and lettuce ; the A.
