The Living Animals of the World, Volume II: Birds, Reptiles and Amphibians, Fishes, Jointed Animals, Molluscs, etc.

The CADDIS-FLIES, of which there are many British representatives, belong to the Hairy-winged group. The larvae of these insects are entirely aquatic, and remind one of hermit-crabs, the front part of the body being clothed with horny armour, while the hinder part is entirely unprotected. In order to escape the attacks of predaceous insects these grubs construct cases round their bodies, which they drag about wherever they go. In one or two instances, however, the case is attached to the lower surface of a stone.

The materials of which these cases are made vary in accordance with the species. In one group, for instance, they consist of pieces of twigs and leaves, cut into short lengths, and arranged side by side in such a manner as to form a spiral band. The larva of another kind uses entire third species employs grains ofleaves, gluing them firmly together and living between them. A sand and tiny stones, which it arranges in the form of a cow's horn. Most curious of all, however, is the case of a caddis-fly which is made entirely of the shells of water-snails. As these shells are, as a rule, still tenanted by their owners, the snails may sometimes be seen attempting to crawl simultaneously in half a dozen different directions, while the grub is dragging them in a seventh.

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All the grubs retain tight hold of their cases by means of a pincer-like organ at the end of the body. When fully fed, they close the aperture at each end of the tube, and assume the chrysalis state, the perfect insects emerging a few weeks later. Although the wings are large and broad, they fly very slowly, and never seem to take more than a short journey through the air. They may often be seen in numbers resting upon the herbage on the banks of streams and ponds, or crawling down into the water in order to deposit their eggs.

STINGING FOUR-WINGED INSECTS, OR ANTS, BEES AND WASPS, AND THEIR ALLIES

BY W. F. KIRBY, F.L.S.

THE order of insects to which the Ants, Bees, and Wasps belong includes a very large number of species. All these are provided with four membranous wings, alike in consistency, and provided with comparatively few nervures. The wings are usually of small size, as compared with the dimensions of the insects, but are very powerful, owing to the fore and hind pair being connected together during flight by a series of little links; and the flight of the insects is usually very rapid. These insects pass through a perfect metamorphosis, the pupa being always inactive; the jaws are provided with mandibles, is also present, and the Photo ly W. P. Dando, F.Z.S., Regent's Park: though a proboscis, or sucking -tube, SAW-FLY. abdomen of the female is armed with an ovipositor, or boring British of of the commonest the larger One instrument, which is frequently modified into a powerful sting, is blackish a insect, measuring hairy species rather more than an inch in expanse, with used to deposit the eggs in their proper position. One pecu-transparent wings bordered with brown. liarity is that several species of ants, bees, and wasps live in large communities, in which the bulk of the inhabitants, on whom most of the work of the nest falls, are imperfectly developed and usually sterile females, called neuters, or workers. This arrangement is also met with in the White Ants, which belong to the order of Lace-winged Insects. Among both the Ants and White Ants the neuters are unprovided with wings; but these organs are present in the fully developed males and females, though soon cast. A great variety of other insects also belong to this order, such as Saw-flies, Grail-flies, and an immense number of parasitic species, generally called Ichneumon-flies, among which are some of the smallest insects known. This extensive order of insects is divided into two principal sections those in which the ovipositor is used as a saw or an auger, and those in which it is modified into a sting. One of the most interesting sections of the Borers includes the SAW-FLIES, in which the boring instrument is modified into a pair of toothed saws, which are used for cutting incisions in leaves, or in the tender bark of twigs, in which to deposit the eggs. These flies have four transparent wings, sometimes stained with yellow or purple, and their bodies are moderately stout and obtuse, and generally black, red, or yellow. The antennae are very Photoby W. P. Vando, F.Z.S., Regent's Park. variable in form, and are sometimes knobbed at the MARBLE GALL-FLY AND GALL. end like those of a butterfly; sometimes they are Found on oak, and not unlike the foreign gall used for formed of a number of long, slender joints; some- making ink.

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times of only three a moderately long basal one, a short middle one, and a long terminal one, composed of a number of joints united into one; and rarely, as in the case of the males of some small species about half an inch long which feed on fir and pine, the antennae are feathered. The grubs are very like caterpillars, and are sometimes called " false " caterpillars; but a true caterpillar (except in one or two very rare exceptions among foreign species) has never more than Photc by W. P. Dando, F.Z.S., Regent's Park. sixteen legs, while these " false caterpillars " have more, often TREE-WASP. as many as twenty-two. They also resemble caterpillars in to similar the but commonVery wasp, builds another way, for the pupae are enclosed in cocoons. One its trees nest in of in instead the ground. interesting Australian species, which feeds on gum-trees, proceeds from a black caterpillar with only six legs. The perfect insect has a blackish head and thorax, with three large yellow spots on the latter, yellowish antennae and wings, and a green abdomen; it measures about an inch and a half across the wings, and has knobbed antennae. larvae an unusual habit, exceptAn allied species, found in Tasmania, is said to tend its young among social insects like bees, wasps, and ants. Among the commonest and the most destructive saw-flies in England are those feeding upon the currant, gooseberry, and pear, of which there are flies which layseveral species, measuring about half an inch across the wings. The commonest their eggs on the gooseberry and currant are yellow, with the head, antennae, and three long spots on the back black, and the wings transparent, with black veins. The grubs are bluish green, with leaf. The best-knowntwenty legs, and numerous black dots; and several may often be seen on one of the PEAR SAW-FLIES is black, with the wings transparent, except the veins; the grub is very like a slug, and is green or yellow, very slimy, with the front of the body much thickened.

The WOOD-WASPS include only a few species, the grubs of which live in the stems of fir- or pine-trees, and theplants, or in the solid wood of trees. One of the largest feeds on fly measures from half an inch to an inch and a half in length, and varies much in size, though is yellow, with two blackthe male is generally much smaller than the female. The female bands, and a stout ovipositor half as long as the abdomen. In the male the tip of the abdomen is black, and ends in a rectangular point. The wings are transparent, with yellow nervures. Next to these insects come the GALL- FLIES, most of which produce round galls on oaks; and in some species we meet with a wingless brood, living alternately with the winged broods, but at the roots of the trees instead of in the open air. The veining of the wings is reduced to one or two veins; the antennae are rather Photo by Scholastic Photo. Co.] [Parson's Green. long, and not angulated; TREE-WASP'S NEST. and the abdomen is Generally built in a thick bush.

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short, and constricted at the base. The flies seldom measure more than half an inch across the wings. Some galls are hard, like the one found on the Turkey oak, from which ink is made; is thewhile others are large and juicy, resembling cherries, or small apples, among which so-called apple of Sodom. Others, like the Bedeguar, which is found on roses, have a mossy appearance. The latter are produced by a small black saw-fly, with part of the legs, and, in the female, the base of the abdomen, red beneath. Some of the smaller gall-flies do not pro-

; duce galls, but are parasitic on other insects but galls are very liable to the parasitic attacks of other insects, especially to those of small brilliant metallic green four-winged flies, belonging to an allied family, with very few nervures, but with a black membranous spot on the front edge of the fore wings, and angulated antennae. Many galls do not begin to grow until the larva is hatched and begins to eat. We now come to five or six families of parasitic species, popularly called ICHNEUMON- FLIES, and immensely numerous and varied. There are probably considerably over 2,000 Photo by W. P. Dando, F.Z.S.] [Regent's Park. ; but they are com- PINE-BOUING WASP (FEMALE). species in England alone known or studied. Some of Formidable in appearance, but quite harmless. paratively little these have beautifully delicate wings, fringed with long bristles, and are among the smallest insects known, being of quite microscopic dimensions. These are parasitic on the eggs of various insects, and some are aquatic. But the more typical ichneumon-flies are of larger size, often measuring more than an, inch across the wings. Their bodies are usually black or yellow, and there is often an irregularly shaped space in the middle of the fore wing, where the veins of the wing converge. In these flies the ovipositor is very short; but in others it is of great length, especially in the case of the largest British insect of this group, which is parasitic on the larvae of the great black-and-yellow wood-wasp, of which we have already spoken. This parasite is as large as the wood-wasp, but much more slender; it is black, with red legs, and two white dots on each segment of the abdomen. The ovipositor, which looks like three black threads, is as long as the whole body. The numerous parasites of which we have spoken usually deposit their eggs in punctures in the bodies of caterpillars or other immature insects, which the grubs devour from within during the life of their victim, leaving it to die when they themselves have reached their full growth. Photo by W. P. Dando, F.Z.S., Regent's Park.