« السابقةمتابعة »
From oak to oak they run with eager haste,
The autumnal equinox happens on the 22d of September, and, at this time, the days and nights are equal all over the earth. About this period, heavy storms of wind and rain are experienced, as well as at the vernal equinox.
To the HARVEST MOON.
But in unclouded majesty thou walkest on thy way.
How many a female eye will roam
To see the load,
The last dear load of harvest home.
Storms and tempests, floods and rains,
Hence away, the season flee,
But may all nature smile with aspect boon,
When in the heavens thou show'st thy face, oh Harvest Moon!
'Neath yon lowly
The husbandman, with sleep-sealed eyes;
God of the winds! oh hear his humble pray'r,
And while the Moon of Harvest shines, thy blust'ring whirlwind
Flies (musca) in this, as in the preceding month, abound in our windows. Of the common house-fly we have already spoken'; we shall now pursue this subject, by describing some other species of this curious genus. The blue flesh-flies feed wholly on the flesh of dead animals, and other decayed substances; as every one knows how difficult it is, in the summer, to preserve meat from their attacks. When they deposit their eggs upon it, the meat is called fly-blown; soon after, maggots are hatched from them, and these are the larvae of the musca vomitoria, or blue flesh-fly. Larvæ of this kind, though with trouble and difficulty kept from the larder, may on the whole be considered as useful to mankind, inasmuch as they destroy and carry away putrid substances. The larvæ of some of these flies, especially that of the musca cæsar, a shining green fly, very common in hedges and gardens, are not content, however, with the flesh of dead animals, but attack living ones that harmless and useful animal the sheep is particularly obnoxious to their attacks, and not unfrequently.
See our last volume, pp. 240, 241..
The sheep knows its enemy, and tries all in its power to avoid it, but in vain: the fly usually settles on its rump, where it is least liable to be molested, and there among the wool lays its eggs; these, when hatched, quickly find their way to the skin of the animal, which having destroyed, they penetrate into the flesh; and, when they happen to be deposited near the abdomen, frequently enter the bowels of the animal and destroy it. Sometimes the sheep is attacked in several parts at the same time; thus diseased, it has motions peculiar to itself, and will frequently wander from the rest, hide itself in some hedge or ditch, and die unobserved. The skilful and attentive shepherd seldom loses any of his flock from this cause; he quickly discovers the malady, and without loss of time applies a remedy, cuts off the wool, clears away the larvæ, and pours train oil into the wound, to which he should add some oil of turpentine.
Cheese in a decayed state, and bacon not thoroughly cured, are the favourite food of the larvæ of another species of fly, much smaller than the preceding: the dealers in these articles give to these larvæ the name of hoppers. If attentively observed, they may be seen to form themselves into a kind of ring, and with great elasticity throw themselves to the height of five or six inches. Swammerdam was the first that noticed this manœuvre, and has described it with that accuracy for which he is distinguished.
A few species of flies live in their larva state after the manner of ichneumons; in the bodies of living caterpillars we have frequently observed them produced from the larvae of the phalana potatoria, or drinker moth, as well as the phalana salicis, satin moth but whether they lay their eggs on the outside, or whether they pierce the skin of the caterpillar, has not yet been ascertained. Most kind of fungi, or mushrooms, as they decay, are full of the maggots of various flies. Linnæus relates that, in Sweden, the larva
of a small fly, which he calls musca frit, lives in the ears of barley, and destroys at least every tenth grain, to the great loss of the husbandman.
The larvæ of some flies live in the heads of the compound flowers, others on the parenchymatous or fleshy part of the leaves of trees and plants, between the two skins; some in the stalks of thistles, where they produce extraordinary tubercles: in short, the habitations of the several species are so numerous, that it would be taking up too much time to mention all of them. We have enumerated those of the most consequence, and by them we see that the maggots of flies are by no means an inactive set of beings, but of great consequence in the economy of nature.
When these larvæ are full grown, the skin hardens, and they change into a chrysalis, most commonly of an oval shape.
Fond as these insects are, in their larva state, of filth and putridity, in their perfect state they are more delicate in the choice of their food, supporting themselves generally by the nectar which they suck from flowers; there are, however, a few instances to the contrary though, in general, a very harmless genus, we are acquainted with two species that are of a sanguinary nature, and which feed on the juices of other flies, which they previously kill. The musca stercoraria, or dung-fly, which we generally observe on cowdung, is one of this sort; there is another species somewhat similar to it, but less hairy, found occasionally in the shop-windows in London, and doubtless elsewhere; first observed by Mr. Benjamin White, sen., of Fleet-street, bookseller, in his shopwindows, feeding on the musca domestica, or common house-fly. One would think that the trunk of this insect was ill adapted for an instrument of death, but certain it is that it makes use of it to pierce the body, as well as to suck the juices of the fly; we have many times been an eye-witness to it. On placing this fly, which we call necatrix, under a wine-glass
with the musca domestica, we have seen it presently seize, kill, and suck its blood: the chief difference that we discern in the proboscis of this and other flies is, that it is stronger, and apparently much stiffer.
Various are the means used to get rid of these troublesome guests, who not only pester us with their numbers, but contaminate our furniture: the most successful antidote is arsenic dissolved in water, with the addition of a little sugar; this they readily sip, and it quickly proves fatal. The composition has been, and is still, held as a secret by some; but, where there are children or servants, it will perhaps be better to bear the annoyance of the flies, than run the risk of poisoning some part of the family',
To a FLY.
Leave this pale, this bloodless cheek,
On yon verdant bank reclining,
But, content with perching on them,
Never fear, I won't complain.
But if still thou buzzest round me,
The chimney or common swallow (hirundo rustica) disappears about the end of the month. The con
See an interesting paper on the Genus Musca, by the late W. Curtis, in the Monthly Magazine for 1814, vol, xxxviii, p. 402.