7649. The duration of insects is extremely variable: the greatest proportion appear to be annual emerging from the egg and passing through the three stages of their existence within the space of a year. But there are a great number of species, particularly among the beetles, which pass three, and even four, years in the caterpillar state; and instances are on record of beetles remaining in timber from ten to fifteen years. The greatest proportion of moths are biennial, passing the winter in the chrysalis state and closing their existence in the succeeding summer. The transitory life of the Ephemera is proverbial; the perfect insect indeed exists but for a day, and seems born only to continue its species; yet in the larva state it enjoys a life of one, two, or even three years.

7650. All insects, as Macleay observes, may be divided into two groups: 1. Apterous insects, having either no metamorphosis, or only that kind of it the tendency of which is confined to the increase of the number of feet: these, as their name implies, are destitute of wings. 2. True insects, or those whose metamorphosis has a tendency to give wings to the perfect or image state, but never more than six feet.

7651. True insects are again divisible into two primary groups; the first of these are organised for mastication in their perfect state, and the second are organised for suction alone. Each of these divisions, according to the system of Macleay, contains five separate orders, the principal characters of which we shall endeavour to make intelligible in common language.

7652. The Mandibulata, or masticating insects, are furnished with jaws of a horny or membranaceous substance, infinitely diversified in their form and structure. They are divided into the following orders:

2. Hymenoptera. The wings are four, clear and transparent. The tarsus (or outer division of the foot) is composed of fire Joints, and the body is armed with a sting. The bee, the ant, and the wasp, are familiar examples.

3. Coleoptera. This well defined and most extensive arder comprehends all insects known by the name of beetles. They have two wings, concealed beneath a pair of hard wing-cases, which meet close together in a straight line down the back. There are many tribes of these insects, which, both in their larva and perfect state, are extensively injurious to man.

4. Orthoptera. The true wings are but two, very large when expanded, and folded lengthways when at rest. They are covered, either partially or wholly, by two wing-cases of a thin, tough, and rather opaque substance, somewhat resembling parchment, and reticulated with small nerves. The leading characters of this order are exemplified in the Blátta, or cock

roach; the pest of tropical countries, and frequently troublesome in our kitchens and larders.

5. Neuroptera. The wings, with very few exceptions, are four in number, clear, transparent, and reticulated with numerous areolets, or irregularly square divisions; the tail of the female is not armed with a sting. Few, if any, of these insects may be considered as injurious: some are, indeed, beneficial; as, from their predatory habits, they attack and devour a vast number of smaller insects. This is more particularly the habit of the green dragon-fly (A'grion virgo, fig. 967. a, which every one may see, during summer, hovering over ponds, and flying about like a hawk in search of its prey. The Ephemera, or day-fly (E. vulgata, fig. 967. b), likewise belongs to this order; and, although not very numerous in this country, is so abundant on the Continent, that they are collected annually in barrows, and afford to the agriculturist a rich and valuable manure.

7653. The Haustellàta, or suctorial insects, likewise contain five orders. Although apparently destitute of jaws, there is every reason to believe, from the observations of the celebrated Savigny, that the rudi. ments of the masticating organs exist in these insects, but that they are so slightly developed as to be totally useless, and only discoverable under a very strong magnifier. The suctorial insects in their larva state are mostly furnished with strong and well defined jaws, and feed voraciously upon animal and vegetable bodies; yet, from the perfect insect being supported by suction alone, it is obvious that in this state they can do no injury to the agriculturist. The orders into which they have been divided are these:

drop of froth of its own making, and is then commonly known as the cuckoo-spit insect; by feeding upon the sap it causes the leaves to curl up, and the growth of young plants is thus materially checked.

convex and thick; the wings also, instead of being foided over each other, are deflexed, and embra e the sides of the body. There are, comparatively, few homopterous insects in England; but the frog-hopper (Cicada spumària L.) is a good example when in its perfect or winged state. The larva resides in a 7654. The different orders of insects we have now enumerated are connected by others of an inferior extent, and which are called osculent orders. But as a description of these is not essential to our present purpose, and as they do not contain any decidedly injurious insects, we shall merely refer the reader to the Hora Entomológica of Macleay, and the Entomology of Messrs. Kirby and Spence.

SUBSECT. 3. Insects injurious to live Stock.

7655. All organised beings, whether animal or vegetable, are subject to be attacked and destroyed by insects. Even man himself is not exempt from the dominion of these small but formidable creatures. For some wise but unknown purpose, there are peculiar species appropriated to receive their nourishment from man alone, and which cannot exist in any other situation. The remedies for these must be prescribed by the physician; but it is the business of the intelligent agriculturist to make himself acquainted with such as are injurious or hurtful to the animals and plants, upon which, the success of his operations mainly depends: for there are as yet no agricultural physicians, to whom the farmer can apply for advice or information when his labours are counteracted by insect devastators. We shall therefore briefly notice the domesticated animals and cultivated plants most subject to these injuries, pointing out the most efficient modes by which they may be checked.

7656. The horse. The principal foes to this noble animal are the horse-bee (E'strus èqui) and gad-fly (CE. hæmorrhoidalis). The first deposits its eggs on such parts of the body as are liable to be licked by the tongue; and the animal, unconscious of what it is doing, thus conveys its enemy into its stomach; the young larvae are there nourished, and become whitish rough maggots (fig. 969. c), which are known by

the name of bots. They attain their full size about the latter end of May, and are voided by the anus from that time until the end of June. On dropping to the ground, they find out some convenient retreat, where they change into a chrysalis; and in six or seven weeks the fly appears. The female (b) is distin guished from the male (a) by the lengthened shape of her body. The inside of the knee is chiefly selected for depositing her eggs, which will frequently amount to four or five hundred on one horse. The other species (E. hæmorrhoidalis L.) is still more troublesome; it deposits its eggs upon the lips, and causes excessive and distressing uneasiness to the animal. Mr. Bracy Clark, who has investigated the history of these insects with great ability, observes that in ordinary cases it is not improbable that they are beneficial to our cattle, by acting as perpetual stimuli or blisters; yet, when they exceed certain limits, they produce disease, and sometimes death. (Clark in Linn. Trans. vol. iii.) The prevention of bots belongs to the farmer, the cure to the veterinary surgeon. The first may be effected by watching the animal at the season when the female deposits her eggs (usually in August and September), and should the horse ap. pear much agitated in its pasture, there will be good reason to suspect it has been attacked by the fly; the eggs may then be removed by the brush and currycomb, or by a pair of scissors. When the disease is certain, one of the best methods to destroy the insect is to fasten a bag net on the horse, for the purpose of catching the excrement, as well as the full-fed larvae. By throwing the dung every morning into a deep pit, any larvæ that may be enclosed in it will thus be prevented from working their way to the surface when their last transformation is about to take place, and their death will cut off a numerous progeny. There are other dipterous insects which feed upon the blood both of horses and cattle; the most formi. dable of these are the horse-flies (Tabani, k, l); others, much smaller (Stomóxys calcitrans), assail him in every situation during summer, and dart their long probosces into his legs and belly. But none are more trying to him than the forest fly (Hippobósca equina L.), which runs sideways or backwards like a crab, and shelters itself in those parts least covered by hair: it may, however, be caught by the hand, when the animal is in his stall; but its substance is so hard, that it can only be destroyed by rolling it between the finger and thumb.

7657. Horned cattle are likewise subject to the attacks of a peculiar species of gad-fly (E. bovis, d, e, f which causes them great terror and distress. The larva (e) is smooth and fat: and the chrysalis opens by a lid (m) when the insect (d) emerges from it. The herdsman may know when this insect appears among his flocks, by the agitation they exhibit; the whole herd, with their tails erect, or carried in some grotesque attitude, gallop about and utter loud lowings. When oxen are employed in agricul ture, the attack of this fly is often attended with danger, as they become quite unmanageable, and, whe ther in harness or yoked to the plough, will run directly forward. Their harness at this season should therefore be so constructed as to be easily loosened. The eggs are deposited within the skin of the animal, and in a wound made by a tube resembling an auger, with which the female is provided. These flies only attack young and healthy subjects; but, independently of the terror they create, do not appear to occasion any material injury. The cattle of Hungary and the neighbouring countries, as also those of Abyssinia, are subject to more deadly enemies, which fortunately are unknown in England. 7658. Sheep are also infested by another species of gad-fly (E. òvis L., g, h, i), which deposits its eggs in the inner margin of their nostrils. The moment the fly touches this part of the sheep, they shake their heads, and strike the ground violently with their fore feet; at the same time, holding their noses close to the earth, they run away looking about them on every side, to see if the fly pursues: they will sometimes crowd together in a rut or dusty road with their noses close to the ground. The larvæ ( are white, flat on one side and convex on the other; they inhabit the cavities of the maxillary sinuses, and crawl, when the animal is dead, into those of the horns and frontal sinuses; when full grown, they

fall through the nostrils, and change to the chrysalis (A), which produces the fly (g) in about two months. Swine, pigeons, and all kinds of poultry are subject to fleas, and lice of various kinds, but never to such a degree as to occasion death.

7659. Fish, in their young or fry state, are the food of the larvæ of water beetles (Dytísci). These insects are frequently seen in great numbers in ponds: they may be caught by a hand net (made of very small meshes), inserted beneath the insect, as he reposes (with his head downwards) on the surface, and then suddenly drawn upwards.

SUBSECT. 4. Insects injurious to Vegetables.

7660. The ravages of insects upon plants commence from the time that the seed is committed to the ground, and continue until the produce is gathered into the barn. These various injuries, in one shape or other, are annually experienced; and many of them, beyond all doubt, will hereafter increase to an alarming extent, if the great body of agriculturists persevere in their mistaken prejudice against crows, rooks, and other useful birds, which Providence has kindly given us, to keep the insect tribes within due limits. We have already noticed the destructive insects which are in a great degree peculiar to certain plants, as wheat, barley, &c. in a general way (Part 111. Book VI.): we shall now enumerate those that infest the grains, clover, pastures, cabbages, and fruits, plantations, as well as those universal destroyers of all vegetables, the wire-worm, the plant lice, and the different species of crane-fly.

7661. Wheat, in every state, is subject to many insect depredators. Mr. Marsham describes a small grub (by some mistaken for the wire-worm), which eats into the young plant about an inch below its surface, devours the central part, and thus causes its immediate death. Out of fifty acres sown with wheat in 1802, ten had been destroyed in this way so early as October. At a later period this grain is attacked by a fly nearly related (according to Mr. Kirby) to the Mosillus arcuatus of Latreille. It makes a lodgement in the heart of the principal stem just above the root, which stem it invariably destroys, giving the crop at first a most unpromising appearance; but it proved ultimately that the plant, instead of being injured, derived great benefit from this circumstance. for, the main stem perishing, the root (which was not hurt) threw out fresh shoots on every side, so as to yield a more abundant crop than in other fields where the insect had not been. When first observed in England, this insect caused great alarm among agriculturists, who thought it might prove the Hessian fly. When the wheat blossoms, it becomes exposed to the attack of a small orange-coloured gnat, which deposits its eggs in the centre of the flower; the larva or grub devours the pollen, and thus prevents the impregnation of the grain. The weevil, a small coleopterous insect (Calandra granària F), is extremely destructive to wheat when in the granary, where it feeds both in the larva and perfect state: against the first, we are acquainted with no remedy, as it lives in the grain; but as this is larger than the perfect beetle, the latter may be in a great measure collected by means of a sieve, large enough for the insect (but not the grain) to pass through it is often found in such numbers, that they have been collected and destroyed by bushels. The same insect, or one very near it, often infests sea biscuit; and can only be killed by baking or heating the biscuits over again in an oven.

7662. Rye is subject to the attacks of a small fly (Músca pumilionis), which introduces its eggs into the heart of the shoots, and occasions a loss of from eight to fourteen plants in a square of two feet. No remedy has yet been proposed for this pest, which, if not extensive, may be checked by plucking the injured ears, and burning them.

7663. Barley, besides other insect foes, has one peculiar to itself, in the shape of a small moth (Tinea hordei K). This fly deposits from twenty to thirty eggs on a single grain; when hatched, each of the larva disperses, and selecting a grain for itself, enters from without, and lies totally concealed: should these moths be observed in a granary, the injury may be stopped by carefully covering the grain, leaving a few handfuls exposed; upon these the moths will deposit their eggs, and by roasting or destroying this small quantity, the rest may be saved from infection.

7664. Oats are subject to few diseases; but, like all other grain, the plants are liable to be destroyed by that universal devastator the wire-worm, of which a more particular account will be found in treating of insects universally injurious to vegetables.

7665. The diseases of peas are mildew and blight, but these are only occasional; its insect enemies, however, are formidable. The principal of these is the plant louse (A`phis), one species of which is peculiar to this plant. In the year 1810, the crops of peas throughout the whole kingdom was so much destroyed by it, that the produce was not more than the quantity sown; and many farmers turned their swine into their pea-fields, not thinking them worth gathering. (Kirby and Spence, i. p. 177.) Beans are exposed to the same injury from another species of A`phis of a black colour, which begins at the top of the plant, and multiplies downwards. In both cases the most effectual remedy is to top the plants at an early period of the infection, and burn the parts so gathered; this plan is likewise advantageous, as it improves both the quality and quantity of the crop. The earlier peas are sown, the better chance they stand of escaping this pest; or if a small quantity of quick-lime is sprinkled upon them when they are a few inches high, experience has shown that the plants remain uninjured, while the Aphis is totally de stroyed.

7666. The diseases of beans are the rust, honey-dew, and mildew. The insects which infest it, and their eradication, have already been noticed. (5256.)

7667. Turnips are subject to several peculiar diseases, and are the food of many noxious insects. On the first appearance of the cotyledon leaves, a whole host of little jumping beetles (Háltica némorum), called by farmers the fly and blackjack, attack and devour them, so that the land is often obliged to be resown. An eminent agriculturist has calculated, that from this cause alone the loss sustained in the turnip crops of Devonshire in 1786 was not less than 100,0007. (Young's Annals, vii. p. 102) Nearly as much damage is sometimes caused by a little weevil (Curculio contractus Marsham), which in the same manner pierces a hole in the cuticle; watering with lime water, &c. may serve to check both these evils.

7668. The caterpillar of a saw-fly (Tenthrèdo L.), entirely of a black colour, appears on the plants so soon as they have produced three or four rough leaves: these have somictimes occasioned considerable mischief, particularly in 1783, when many thousand acres were, on this account, ploughed up. These caterpillars are sought after with so much avidity by crows, rooks, and magpies, that those farmers, whose good sense have led them not to destroy, but rather to encourage, these useful birds, need not fear any great damage from this insect. To destroy it in the most effectual way, watering or sprinkling with lime has been strongly recommended.

7669. The caterpillar of the turnip butterfly (Pier's napa F.) is also sometimes found on the turnip in great numbers: nearly fifty of the grub, which so much resembles the wire-worm, and which we have before alluded to (766.), have been found just below the leaves of a single bulb. These may, in a great mea.

sure, he enticed and destroyed, like the true wire-worm, which also does extensive injury to turnips. The small knob or tubercle, often observed on the roots, is inhabited by another kind of grub, probably the larva either of Curculio contrác tus M., or Rynchanus assimilis F., two small weevils. These, however, do not seem to affect the growth of the plant.

7670. The vegetable diseases of the turmp are the mildew (by some considered the effect of insects), distortion of the root (known principally by the name of fingers and toes), the anbury, the canker, and gangrene, or wasting from water and frost. None of these injurious diseases, as far as is known, admit either of prevention or cure: under favourable circumstances of soil, culture, climate, and weather, they seldom occur; and therefore all that the cultivator can do is to prepare and manure his land properly, and in the sowing season supply water when the weather is dry.

7671. The hop is liable to many external and internal diseases: by the first term we must be understood as alluding to injuries caused by insects, while those which belong to the vegetable are certainly internal. When the plants first emerge above the ground, they are infested by a small beetle, vulgarly called the flea.

In a more advanced state the tops and branches are devoured by the hop A`phis, known to some by the name of the green fly, while at the same period the rects are subject to the attack of the caterpillar

of a singular species of moth, named by collectors the ghost. The vegetable diseases incident to the hop are, the honey.dew, the mould, the blight, and the fire-blast, all of which take place at different times, though mostly when the plant is full grown.

7672. The hop insect, improperly called the flea, has no other resemblance to that animal, than that it is small, and jumps. It is, on the contrary, a beetle (Háltica concinna), of a species closely allied to that which infects young turnips. In its perfect state it commits great havoc, by eating the tender shoots of the young plants. It has been said, that this insect abounds most in seasons when the nights are cold, and the days hot and dry. Others assert, that it is most frequent on plants in grounds that have been dunged the same year, on which account it has been recommended, that the manure used for Covering the hills should be previously well mixed as before directed (6019.), and applied either over all the land, or only on the hills; but this and various other plans do not appear to have originated in a due knowledge of the subject. Nothing as yet appears known regarding the nature or habitation of this insect in its larva or grub state; and unless it is ascertained to live, during that period, in manure, the above plan will inevitably prove abortive. The deadly effects of lime upon insects, however small, has been extensively proved, and should be resorted to in all cases where the expected value of the crop will bear the expense of its application. Mr. Samuel Curtis has stated in the Horticultural Transactions (vol. 6. part 2. p. 124.) the very great advantages he has derived by applying pulverised quick-lime to fruit-trees; and there is no doubt that the same remedy would be equally successful if extended to the turnip and hop plants, so soon as the young leaves begin to appear, or on the first symptom of their being attacked by this Insect.

7673. The hop louse, called by some the green or long-winged fly, is a species of Aphis peculiar to the plant; it makes its

appearance towards the end of May, and during the two next months. These insects propagate so prodigiously, that whenever they have once made a settlement upon a hop plantation, they seem to have baffled every art of man, either to extirpate them, or even to check their increase. It is a vulgar error to suppose that they come or are carried away by any particular wind; or that mildly warm weather will affect their removal. It is true, that on such days the perfect insects are seen on the wing; but it is only to extend their destructive race to other plantations, and to establish new colonies. Sudden and viclent showers of rain, or gusts of wind, causes the death of millions; and vast quantities are devoured by sparrows and other small birds; yet these are accidental and insufficient palliatives. It is, therefore, strongly recommended, that the process described by Curtis, of throwing pulverised lime by the instrument he used, be tried on hops infected by the Aphis; and we venture to predict that it would be attended with considerable

success.

7674. The ghost moth (Hepialus hùmuli F.) deposits its eggs near the roots of the hop plant, upon which the larva or caterpillar feeds, sometimes doing them considerable injury. The best preventive is to destroy the moth, and this may be done by attracting it at dusk to a candle and lantern, carried by a boy over the grounds, who could knock down very many with his hat. The moth is of a tolerable size; and one sex is entirely white, so that it may be seen, even at night, with ease. It hovers over a small spot of ground, so that a good catcher of insects might clear the plantation in a few evenings. In 1826 the ghost moth appeared in many parts of Warwickshire, in very considerable numbers.

7675. Clover is very subject to be injured by a very small weevil (A`pion flavifemoràtum K.), which at all seasons feeds upon the seed of the purple clover, while another species of the same tribe (A. flavipes) devours that of the white or Dutch clover; the injury, unfortunately, cannot be known while the plants are growing, as they have then every appearance of being perfectly healthy. The young shoots of the purple clover are often devoured by the same little jumping beetles (Háltica F.) which attack both turnips and hops.

7676. Pastures in general are often destroyed to a very great extent by the larva or grub of the cock. chafer (970. a), known in different parts of England by the following provincial names:-Brown tree-beetle, blind beetle, chafer, Jack horner, Jeffry cock, May. bug, brown-clock, dor, and miller.

7677. The ravages of the larva are even exceeded by those of the perfect insect, which sometimes appears in this country in prodigious multitudes, and, like a flight of locusts, devour every green thing on the face of the earth. The eggs of this terrible devastator are white, and are deposited in the ground, where they soon change into a soft whitish grub with a red head, and about an inch and a half long (b). In this state it continues four years, during which time it commits most destructive ravages on the roots, not only of grass, but of all other plants and young trees. Whole acres of the richest pastures are thus rendered unproductive; all verdure is lost, and the turf will roll up almost with as much case as if it had been cut with a spade. The whole of this injury being carried on under ground, admits neither of preventive nor palliative measures; but the destruction to be expected from the perfect insect may yet be prevented. If the dried and withered turf is now removed, the soil underneath will appear turned into a soft mould for about an inch in depth, like the bed of a garden; in this will be found the grubs, lying on their backs in a curved position, and vast quantities may be gathered and given to pigs and poultry. When full grown, the larvae dig in the earth to the almost incredible depth of five or six feet, spin a smooth case, and then change into a chrysalis. In this inactive form they remain until the following spring.

7678. The perfect insect or beetle then comes from the ground, and commences an immediate attack upon the leaves of all trees. Their numbers are sometimes so immense, that, was not the following account fully authenticated, we should almost doubt its correctness:-In 1688, the cockchafers appeared on the hedges and trees in the county of Galway in clusters of thousands, clinging to each others' backs in the manner of bees when they swarm. During the day they remained quiet, but towards sunset the whole were in motion, and the humming noise of their wings sounded like distant drums. Their numbers were so prodigious, that for the space of three miles they darkened the air; and the noise they made in devouring the leaves was so loud, as to have been compared to the distant sawing of timber. In a very short time the leaves of all the trees for some miles were destroyed, leaving the whole country, in the middle of summer, as naked and desolate as it would have been in winter. Swine and poultry devoured them in vast quantities; they waited under the trees for the clusters

dropping, and became fat upon this unusual food: even the lower orders of the people, from these insects having eaten up the produce of the earth, adopted a mode of dressing them, and used them also as food. Towards the end of summer they are said to have suddenly disappeared; and we have no account of their having been seen in any considerable numbers the following year. (Phil. Trans. xix. p. 743. &c.) These grubs did so much injury about seventy years ago to a poor farmer near Norwich, that the court of that city, out of compassion, allowed him 251.; the man and his servant declaring that they had gathered eighty bushels of these beetles. The best, and indeed the only effectual remedy for the destruction of the perfect insect, is to shake the trees or bushes at noon, when they are either asleep, or in a state of stupor, and then to sweep or gather them up. One person in this way has been known to capture a thousand in a day, which, on a moderate calculation, prevented no less than one hundred thousand eggs from being laid. Some judicious farmers plough the ground when they have reason to think it is infested by the grub, and this is generally indicated by the rooks attempting to reach them. They are also greedily devoured by crows, magpies, and jays, whose sole employment, for nearly three months in the spring of the year, is to search for insects of this sort; and the destruction they cause among them is above all calculation.

7679. Cabbages and other esculent vegetables are well known to be greatly injured by the caterpillars of two different kinds of white butterflies (fig. 971.), one of these (Pleris brássica, c) is much larger than the other: the caterpillar is pale yellow, with black spots (a): when full fed, it shelters itself on walls, pales, or trunks of trees, and changes into the chrysalis state (b), in which it still preserves the same cast of colouring: the perfect insect (c) appears early in spring, and continues until the end of summer. The other species of caterpillar is green (d); the chrysalis (e) is of the same colour; and the butterfly (f) is produced about the same time as the preceding. Various methods have been recommended to prevent the winged insect from depositing its eggs upon those plants which nature has given them the instinct to select; these are, however, ineffectual, and in many cases sufficiently ridiculous: handpicking the larva, and searching for the chrysalis, are the only plans we can recommend, either for these or the gooseberry and currant caterpillars.

7680. Fruit trees of all kinds, and their produce, are attached and devoured by a great variety of insects, an enumeration of which will be found in our Encyclopedia of Gardening. We shall, however, advert to those curious minute insects (Thrips Physapus, fig. 972. f, h) so often seen in flowers and blossoms during the spring, and which, in their natural size (f), appear like short black lines. Nearly all fruit trees are liable to considerable injury from different species of Cóccus or cochineal insects. They are mostly so small

971

(fig. 972. a, d), that their form cannot be well distinguished without the aid of a magnifying glass; many of them resemble small scales or scabs fixed on the bark and shoots. One is entirely of a brown colour (Cóccus persicòrum a): when magnified (b) it somewhat resembles the tortoise beetle (Cassida L.), the legs and head being only discernible when the insect is turned on its back (e). Another (C. fol. quercus, 972

d, e, e) does much injury to the oak; while the C. fagi attacks the twigs of the beech (g), and causes small round excrescences to appear; these are, however, very different from the gall apples of the oak (j), which are often found of a considerable size, and are produced by the Cynips quercus folii L. (k), or oak gall-fly, and always contain either the larva or imperfect insect. The weevils (Curculionidae) form an exceedingly numerous family, subsisting principally upon fruit, seed, and grain. One of the largest found in this country is the nut-weevil (C. nùcum, fig. 970.e, e), the larvae of which (c, d) are the maggots so frequently found in this fruit.

7681. The insects injurious to plantations are less numerous in this country than on the Continent, yet

973

we have two species whose devastations of late years have caused much alarm and extensive injury. The pine plantations in various parts of Britain have suffered from the great saw-fly (Urócerus gigas Lat), the larva of which, feeding upon the heart of the tree, and boring it in all directions, soon destroys it. Another small insect of the beetle kind (Scolytus destructor F., fig. 973. d magnified) is equally deadly to the elm; and from being more common, and propagating very rapidly, is more to be dreaded. The sudden destruction of a large proportion of the elms in St. James's and Hyde Parks has recently called the attention of government to this beetle; and at the request of the noble rangers, Mr. Macleay undertook to investigate the evil: the result of his observations have been since published (Edinb. Phil. Journal, No. 21.). It ap. pears that the female (a) may be found upon the trunk of the elm from March to September: she first penetrates through the bark, and then proceeds to form a passage between that and the wood, depositing her eggs during her progress on each side; when these are exhausted, the parent dies, and is often found dead at the extremity of the passage (b) thus formed. When the eggs are hatched, the young larvæ immediately begin to feed by working nearly at right angles (cc) from the path of the parent, each proceeding in a parallel direction and close to his neighbour: in this state they may be found in January. To stop this mischief as much as possible, Mr. Macleay recommends that the trees should be inspected twice a year: in summer, when the perfect insect is on the wing; and again in winter, when infected trees should be cut down and burned, or subjected by fumigation to such a degree of heat as may destroy the larva; or the bark may be covered with a mixture of tar and train oil, in March, to a certain height from the ground, applying this composition only to such