several pieces, which in many instances is modified into a

poison-bearing sting. The pupa is quiescent, and the larva

is both quiescent and without feet, except in one group, that of

the Saw-flies.

In all books that treat scientifically of the Hymenoptera, a

vast amount of technical language will be found. Many of the

words, such as those which express the general divisions of the

body, the parts of the mouth, the anatomy of the limbs, &c., are the same as those which we have already learned when treating of Beetles. But, in this order of insects, very great stress is laid upon sundry portions of organisation which are but little considered in the Coleoptera, and therefore I have given a chart-drawing of a hornet, similar to that of the Stagbeetle on page 9. I strongly advise the young entomologist to take a hornet, or even a wasp, and make out all the parts by means of this diagram, and he will find that if he colours the diagram he will fix it more firmly in his memory. The colouring should be taken from the insect itself.

According to Mr. Westwood’s system, the Hymenoptera are divided into two great sections, namely, the Terebrantia, or Borers, and the Aculeata, or Sting-bearers. We will proceed with these sections in order. The first subsection is called Serrifera, or Saw-bearers, in which the abdomen is attached to the thorax by the whole of its diameteii and the larvae feed upon vegetable substances, and have a well-developed mouth furmshed with mandibles. This subsection includes the whole of the Saw-flies and Gall-flies.

We will begin with the insects which are so well known as Saw-flies, and are scientifically termed Tenthredinidse. This word is a very old one, being used by Aristotle in his ‘ History of Animals to signify some kind of bee or wasp. It is formed from a Greek word signifying to gnaw or nibble. The names Andrena, Pemphredon, &c., are derived from the same source. In these insects, the wings are large, with many ‘ complete ’ cells, i.e. cells closed on every side by nervui-es, and having a large stigma or spot. The abdomen has no footstalk, and is fmnished in the females with the extraordinary apparatus which has gained for the group of and Hymenoptera the popular

appropriate name of Saw flies.

At the extremity of the abdomen and on its under surface are placed two flat horny plates set side by side. These are the saws, and, like the well-known ‘ tenon-saw ’ of carpenters, have one edge toothed, and the other strengthened by a flat thick plate. On examination with a tolerably powerful lens, the teeth are seen to be most elaborately constructed. Instead of being mere simple teeth, like those of a saw, each tooth is formed of a cone set in a footstalk, the cone being deeply cut into eight or ten deep grooves, having a sharp edge between each. This structure is wonderfully adapted to prevent the saw from clogging with the green wood in which it has to work, and might with advantage be copied by our tool-makers. The toothing of the saw differs in the various species of Saw-fly, but the form which has been described is found in some of the insects with which our list commences.

The strengthened backs of these saws are received into grooves or sheaths in which they slide backwards and forwards, and they are so contrived that while one saw is being thrust forward, the other is being drawn back. There is not the least difficulty in getting these beautiful instruments under the microscope. They are of course best seen in the recent specimen, but even after the insect has been long dead and dry, the saw can be detached with a little careful manipulation. The object of the saw, which is indeed a modification of the ovipositor, is to prepare a resting-place for - the. eggs. By alternately working the saws, a groove. is rapidly, cut in a twig, or a leaf rib, and an egg is then passed between the saws and deposited in the groove, where it is fixed by a small drop of liquid secreted by the insect. The ' number of grooves and of the eggs deposited in them varies according to the different species of Saw-fly. Even if the observer should fail to see a Saw-fly in the act of depositing her eggs, he can always see the grooves and the eggs in them, by carefully examining the leaves and yoimg twigs of various trees. The common currant is often much damaged by Sawflies, and on a single bush there will be scarcely a leaf in which the grooves cut by the Saw-fly cannot be foimd. These grooves are made on the under side of the leaf, partly because the nervures are thicker, and partly because the eggs are sheltered from the rain.

In process of time the eggs are hatched, and from them are

produced larvse which very much resemble those of moths. They can, however, be at once distinguished from them by the fact that they have more legs and ‘ pro-legs,’ or false feet, than the true caterpillars. No caterpillar has more than sixteen of these members, whereas the larva of the Saw-fly has from eighteen to twenty-two. One of these larvae, that

1 Hylotoma roS£B. 2. Crcesus 3. Athnlia spinarum. 4. Allantns septentrionalis. Bcrophularia. a. Croesus larva. 6. Athalia larva, c. Allantns larva. d. Hylotoma, antenna. «. CrcESUS, antenna. /. AthaUa, g. Allantns, antenna. antenna. of Cimhex lutea, is shown on Plate IX. Fig. 3, and others are seen on Woodcut XXIX. Figs, a b and c.

Having thus rapidly gone through the chief characteristics of the Saw-flies, we will examine them detail. somewhat more in

The first insect on our list is Cimhex hdea, which is shown on Plate IX. Fig. 1, of its natural size, and a more detailed

drawing is given on Woodcut XXX. Fig, 1, in order to show the characteristic details of the genus. In this genus the club of the antennse consist of two joints soldered together, and the rest of the organ is formed of five joints. The spurs are rather short and blunt, and in the male insect the tarsi of the fore-legs are spined beneath. There are about eight British species of Cimbex. The colour of the present species is, as may be inferred from its name, yellow, and all inexperienced observers might easily mistake the insect for a wasp, especially when flying.

The larva is shown both in Plate IX. Fig. 3, and in Woodcut XXX. Fig. a, the latter figure being given in order to show its structure. It has in all twenty-two feet and four legs, and the body is covered with very small tubercles. Just over the spiracles, or breathing holes, there are some apertures, through which the larva can spirt a greenish fluid to some little distance. It ejects the fluid when it is alarmed, but the supply is limited, and each successive discharge is weaker than its predecessor. Like most Saw-fly larvae its colour is greenish grey. Contrary to the usual practice among insects, this larva prefers the upper side of the leaf, where it may be found partly coiled up, with its tail in the centre. It feeds on various trees, such as the elder, the birch, and the beech, but Mr. F. Smith tells me that he has generally found it on the willow.

In process of time, the larva attains its full growth, and then sets to work at spinning a cocoon in which it can imdergo its transformations. The cocoon is wonderfully tough and leathery in texture, brown in colour, and is rather fluffy on the outside. It is affixed to sonae twig of the tree on which the larva fed, and in winter time is very conspicuous owing to the absence of leaves. One of these dwellings is shown on Plate IX. Fig. 2. If one of these cocoons be carefully opened before the insect has made its final change, the pupa can be seen lying quietly in its cell like a child in a cradle, and apparently as helpless. It remains for a considerable time in the cocoon, and finally makes its escape at one end of its dwelling.

On Plate IX. Fig. 5, is seen a very fine insect, known as Tvichiosoinui Iucot^th. The name of this scientifically genus is formed from two Grreek words, signifying Hairy-body,

Plate Ix. Saw-Flies, Gall-Flies, And Sirex.

Cimbex lutea. 2. Cimbex, cocoon, 3. Cimbex, larva. 4. Lyda hortensia. 6. Trichiosoma lucorum. 6, Cynips Kollari. 7. Sirex juvencua (Male). Plants : — Oak, Fir, and Hawthorn.

S':.

and is given to the insects because their bodies are thickly

covered with hair, instead of being nearly naked like those of

the preceding genus. The whole appearance of the body is so

bee-like that most persons who see the insect imagine that it

belongs to the bees and not to the Saw-flies. It can, however.

Cimbex lutea. 2. Tenthredo zonatus. 3. Cryptus pallipes. 4. Lophyrus pini. a. Cimbex larva. b. Lophyrus larva. c. Lophyrus, cocoon, d. Do.- antenna, male. e. Do. antenna, female.

be distinguished by the shape of the antennae, which are terminated by round knobs composed of three joints fused together. The rest of the organ is composed of five joints, -the colour of the insect is dark brown, and the wings are darkish, with a smoky streak along their lower edges.

The insect is common upon whitethorn, and may be seen in all these stages. The larva, like that of the last-mentioned Sawfly, prefers the upper surface of leaves, and coils itself up in a

similar fashion. Tlie cocoons are not easily seen as long as the leaves are on the trees, hut if a whitethorn hedge he carefully examined in the winter, the cocoons of the Trichiosoma will probably he found in tolerable plenty. The twig on which they are fixed should he cut oflf, and the cocoons placed in a box with a cover of wire gauze in order to await the appearance of the perfect insect, which takes place in the spring. At that time of year, the fly is not at all uncommon, and may he captured with the net as it flits about the hedges, seeking for convenient spots wherein to deposit its eggs.

I well remember taking some of these Saw-flies when beginning my entomological career, and, not having access to hooks, being entirely puzzled by them. At first, I naturally took them for bees, but could not understand how the knobbed antennse could belong to a bee. Then, the creatures, though they were females, had no sting, and as I was not then aware that Saw-flies of such magnitude existed in this country, I was naturally puzzled. Yet, the very fact of this bewilderment served to fix the creatures so firmly in my mind that, even at this distance of time, I could draw from memory the first Trichiosoma that I ever caught. The saws of this insect are well worthy of examination, as they possess the cone-tipped teeth which have been described on page 298.

The larvae can he taken at the end of summer, when they are nearly full-fed, and as they are very large and conspicuous, there is little difficulty in obtaining them.

Page 53 of 117