A warm spring day is the time in which the Humble-bee Fly may generally be seen. I have taken many of them in Bagley ’ Wood, and found no great difficulty in catching them when | their ways were learnt. It is useless to run after one of these insects, as the least movement will terrify it, and send it off far I beyond the reach of the net. Whenever I wanted to catch a Bombylius, I used to look out for a patch of primroses on which the sun was shining, and to wait there with the net ; placed close to the flowers in readiness for a stroke. After > waiting some little time, and taking care not to make the ■j slightest movement, a Bombyliiis was nearly sure to come to [

flowers, and hover first over one and then over another as if i the to ascertain which blossom contained the most honey. Having at last fixed upon a flower, it would plunge its proboscis into it, j and then a quick stroke of the net would secure it before it had time to dart away.

by a considerable number of Flies, we come to the

Passing Asilidse. In this family, the body is long and the family thorax narrowed in front. The wings have some perfect celL,

and tlie proboscis is stretched forward and about as long as the liead. There are many of these insects, and as their habits are very similar we will take the present species as an example.

The Gtreat Hornet Fly {^Asilus crahroniformis) is shown on Woodcut LXXI. Fig. 1. Its colouring is simple, but exceedingly bold. The thorax is chrome-yellow, rather darker behind, and two blackish stripes run parallel to each other on the back. The basal half of the abdomen is velvet-black, and the rest bright chrome-yellow. The wings are yellow and so are the legs.

At a little distance this insect really looks very much like a hornet, and it has all the predacious habits of that insect. It is seldom seen without a fly or other insect in its grasp, the fore-legs clasping it firmly and the beak driven into the body of its victim. It is spread over the whole of England, but jnefeis sea-side downs and similar places. My own specimens were all taken on the great rolling chalk-downs of Wiltshire.

It has rather a peculiar mode of flight. It keeps near the ground, and there waits until it feels that it is in danger, when it rises and, with a sort of uncertain drifting movement, flies some ten or twelve yards, and then settles again. If followed up it is easily taken, as it soon appears to tire of these repeated flushings, and allows the pursuer to come quite close before it will move. This is by far the handsomest and most conspicuous of its family, all the others being comparatively dull. At big. a is shown the tarsus of this insect.

The next family which comes before us is the large and important family of the Syrphidse, popularly known as Hoverers, Hawk-flies, and Drone-Flies. In this family the head is hemisplierical, and in the males the greater portion of it is occupied by the eyes.^ The antennae are three-jointed, and bear a bristle, as seen at b ig. c on Woodcut LXXI. There are several perfect cells in the wings.

We shall take several examples of this large family, on account of the peculiar habits of their larvae.

On Woodcut LXXI. Fig. 4 is shown the common Drone-Fly {Eristalis tenax), which is so plentiful in the summer time, and is so often taken for a bee on account of its form, colour’

large wings, and humming flight. Moreover, it has a hee-like habit of moving its abdomen up and down as if threatening to use a sting, and in consequence of this resemblance it is very needlessly dreaded by the generality of those who see it. Its colour is variable, but is generally some shades of brown, grey, and black. It is very swift on the wing, and has a quick darting flight much resembling that of the Humble-Bee Fly, which has just been described.

Tire larva is a most curious being. It is a worm-shaped grub, the tail of which is prolonged into a wonderfully long telescopic tube, by means of which the creature breathes, the air-tubes passing through it exactly as was related of the gnat larva. When this telescopic tail is prolonged to its greatest extent, it is about as thick as an ordinary pin. Owing to the transparency of its walls, the double air-tube within it can be easily seen, and when the tail is elongated so are the air-tubes. But when the larva is frightened and contracts its tail, the airtubes may be seen doubled up in an apparently complicated but really simple manner, just below the base of the tail. As may be supposed, when a telescopic tail of more than two inches in length is suddenly shut up and reduced to a nullity, the elastic air-tubes within it must undergo a process of folding. This is done with such precision tliat the tail can be gradually extended or smartly closed over and over again, and yet not one single fold of the enclosed air-tubes ever hitches over another so as to impede the play of the all-important tubes.

This may appear a very simple matter, but it is in fact a very complicated one, as may be seen from the following parallel. Suppose that an ordinary telescope were drawn out to its fullest extent, and that two india-rubber tubes were stretched inside it, parallel to each otlier. Now if the telescope be closed, the tubes fall of necessity into coils in the lowest and largest joint of the telescope. Open the telescope again, and the two tubes will again be straight and parallel, provided that they have not interfered with each other while they were coiled up together at the bottom of the telescope. Let but one single coil envelope another, and either the telescopic joints cannot be opened, or one of the tubes is snapped.

I have dissected numbers of tliese larvic, and have always

been impressed with the wonderful power and foresight dis- ])layed in this one point. Suppose that an Eristalis larva, or Eat-tailed Maggot as it is popularly called, be put into spirits of wine for the purpose of killing it, the tail at once contracts, so that no one who was not acquainted with the creature could recognise it. If, however, the tip of the tail be seized between the points of the forceps, and the organ be drawn out to its full extent, the air-tubes can be seen to unfold themselves with the most perfect accuracy. A hitch never occurs, but the coils, or rather the folds, open out one after the other, and the two convoluted tubes become straight and parallel.

This remarkable tail is rendered necessary on account of the habits of the larva which owns it. The creature lives in a manner which to us would be about as miserable as can be imagined. It passes the whole of its life immersed in thick and semi-putrid mud, witli its head downwards. The mud cannot be too thick, too black, or too noisome for this larva. There was one place where I could procure as many Eat-tailed larvae as I liked. Just under the eaves of a church roof a large tub had been sunk in the ground, for the purpose of catching the rain-water. Year after year it liad been neglected, and it had become two-thirds full of a horribly fetid mud, composed of dead leaves, worms that had crawled over the edge of the tub and fallen into the water, frogs and toads that had foolishly jumped into the tub, forgetting that they could not jump out again, quantities of moths, beetles, and other insects that had inadvertently fallen into the water and been drowned, fieldmice that had overbalanced themselves in trying to drink, and other substances too numerous to mention.

The state of such a mud can easily be imagined, and yet this horrible compound was in its way a Paradise to vast numbers of Eat-tailed Maggots, Avhich were busily employed in their beneficent task of transmuting death into life, and of devouring this poisonous and mephitic mud, so that it might be changed into bright and active flies. Such is indeed the task of these and many other insects, and it is absolutely impossible to exaggerate the debt of gratitude which we owe them. Every Drone-Fly which we see is a living proof that a certain amount of pestilential matter has been consumed and rendered harmless, and it is evident that such insects ought to be encouraged

and protected in every mode that lies in the power of civilised | * man. | *

To return for a moment to our larva. It is impossible that any creature could obtain air while buried in the thick mud * ' which has just been described. There are many creatures, especially Crustacea, which do live buried in mud, but then ( they always form a slight tunnel, so that they are really immersed, not in mud, but in water. The Rat-tailed Maggot, however, is really buried in the mud, and needs some apparatus for communicating with the air. This apparatus is supplied by the telescopic tail of the larva, which can be projected out of the mud, and by means of the double air-tubes which it contains conveys the necessary amount of oxygen to the system.

The ‘ tail ’ can be retracted with great rapidity. I had a great number of the larvae in a bottle, on the bottom of which was placed a layer of mud in which the creatures could bury themselves, and the rest of the bottle nearly filled with water. When all was quiet, all the tails remained quite upright, and looked like a number of young aquatic plants. But if the slightest jar were given to the bottle, all the tails were j retracted, and the water was left clear and empty as if by a ; conjuring trick. ;

When the larva is full-fed on the disgusting substances which form its dainties, it extricates itself from the mud by means of seven pairs of tiny hooked feet, crawls ashore, buries itself in the earth, and there awaits its change. The larval skin then shortens and hardens, and the pupa separates itself from its former skin, which then acts the part of a cocoon. In process of time the transformation is complete, and the dull motionless grub that had passed its whole life sunk in the dark ? « and obscene mud is transformed into a creature of light, gifted with enormous eyes and glittering powerful wings, and darting « through the air with a rapidity so great that the eye cannot ^ follow its track. The specific name of tenax is given to the insect on account of the tenacity with which it holds to any object that it may grasp with its feet.

On Woodcut LXXII. Fig. 3 is represented an insect called Merodon clavipes.

In this genus the body is blunt and hairy, the third joint oi j

the antennae is oval, and the thighs of the hind legs have a strong tooth at their tips. The generic name Merodon refers to this structure, signifying literally ‘ thigh-toothed,’ and the specific name of clavipes, or club-footed, alludes to the thickened and club-like form of the hind leg.

This is rather a pretty insect. The thorax ig shining black, with grey hair at the sides, and the abdomen is black, adorned

Volncella pellucens. 2. Voluoella plumata. 3. Merodon clavipes. 4. Syrphns Incornm. a. Volncellapellncens, olypens. i. Do., antenna. c. Do., ocelli. d. Do., front of head! e. Syrphus lucoriim, antenna.

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