List of Insects that Damage Crops | Zoology

Here is a list of insects that damage crops: 1. The Rust 2. Millipedes and Centipedes 3. Tephritis Solstitialis.

1. The Rust:

The disease, which so materially affects the carrot crops and deteriorates their value, is occasioned in the first instance by the larvae of a small fly. These maggots eat passages in the tap-root, and the carrots gradually die off, changing to an ochreous or ferruginous colour where they have been eaten where they are termed “Rusty” by cultivators, and they become of little value; for the fibrous roots perishing, or being arrested in their growth, from a want of free and healthy circulation, the plants sicken if they do not immediately die.

They lose their saccharine qualities, are consequently no longer sweet to the taste, and eventually they become black and rotten, especially when stored. The flies and their maggots are found through the summer, and the latter even in the winter, but they leave the toots to become pupae in the earth, in which state they remain until the spring, but the summer broods hatch in three of four weeks.

On digging up some carrots in a clay soil the end of December, 1844, which was small and crowded from having been neglected. It was found a considerable number of them maggot-eaten or rusty. On the tops were small black slugs; white Podurae were also running out and in to the cavities, and towards the apex of the roots large excavations were made, whether by slugs, worms, or millipedes.

The most remarkable appearance, however, was occasioned by whitish, shining, conical objects sticking out of the sides horizontally, sometimes projecting nearly a quarter of an inch: which on being exposed to the light often withdrew themselves into the holes they had made in the carrot, and on diving these longitudinally, various labyrinths were exposed, some of which entered the very heart of the root these cavities were dirty and brown, which coloured was suffused to a considerable extent.

The maggots are ochreous and shining, cylindrical, pointed at the head and obtuse at the tail they resemble cheese hoppers, but they cannot leap: they are exceedingly transparent, so that every internal part is visible.

The head is a black horny substance, which contains the moth; this is alternately thrust out and contracted with great activity, the tip forming a hook, the base being forked like two spreading black horse hairs; the body is composed of eleven rings besides the head and tail, this being rounded and producing two little black horny tubercles; from these extend two somewhat parallel pale lines which may be traced to the head; the intestines are also pale, but beneath the antepenultimate segment is a bag of reddish excrement, more of a purple tint than the carrot which it had been feeding upon.

The pupa is cylindrical, horny, shining, and coppery-ochreous finely striated in rings, and of a pale rusty colour at the extremities; the head is sloped off very much, forming an oval concave lid, with a thickened margin, which lifts up to allow the fly to crawl out when it hatches, and in front are two minute black tubercles; the tail is rounded and furnished with two little black points the fly which it produces belongs to the order Diptera, the family Muscide, the genus Psila, and was named Rose by Fabricius.

Psila Rose-The Carrot-Fly:

It is shining, of a pitchy black, with a greenish tinge, and clothed with pale hairs the head, is globose and rusty ochre, with a few bristles; eyes lateral, orbicular, and black after death; on the crown is a black spot with little simple eyes in triangle; the face slopes inward, and the two drooping horns are inserted under the projecting forehead; the third joint is oval and black at the tip, and on the back is inserted a pubescent ochreous bristle; the trunk is oblong; the scutellum is small, trigonate, and rusty; the six-jointed abdomen is rather small, oval, and conical at the apex in the female, and furnished with a telescope form contractile ovipositor the wings lie horizontally on the back when at rest, and extend beyond the tail, being ample, iridescent, with a yellowish tinge, and all the nervures are bright ochreous; the poises are small and whitish; the legs are bright ochreous, and pubescent; the feet are five-jointed, the basal joint very long, the fifth small, with two little black claws and two small cushions or pulvilli.

Psila nigricomis of Meigen is very like P. Rosoe, but rather smaller and the third oval joint of the horns is entirely black. It is not always the mature crops which suffer from these maggots, for some young carrot roots were drilled through by them, and few years back young crops were similarly affected, but the maggots were not discovered where the spots existed, owing probably at that time to the minuteness of the recently produced larvae.

With a view of rescuing the carrot crops from this pest, it has been recommended that as soon as the outer leaves become yellow and wither, which are indications that the root has been infested, such plants should be taken up without delay, and the grubs destroyed by immersing the roots in hot water.

If land be left, as allotments often are, to remain through the winter just as the crops have been drawn, not only that plot of ground, but the whole neighborhood, may be deluged with noxious and troublesome insects; whereas, by trenching in the autumn, the pupae of these and other flies are not only subjected to frost, snow, and rain, as well as extreme transitions of temperature, but the inhabitants of the soil are exposed to the prying eye of the robin and various birds, which subsist to a great extent upon insects and seeds during the winter.

Before sowing carrots, it is a great security against the Rust to give a dressing of spirits of tar and sand. It is even reported that pigeons’ dung or cow-dung, pointed in at the time of sowing, will secure the crop from these maggots. Old turf well incorporated with quicklime, at the rate of eighty, loads per acre, on a light soil, produced a fine crop entirely free from insects.

If quicklime alone be sown over the surface, let it lie two or three days and repeat the operation, after which it is to be ploughed in: this well free the soil from insects and slugs which prey upon the carrot crops, but of course the drier the weather is the better the lime will take effect. The spirit of tar, however, has been so often successfully tried, and it is so applicable to field culture.

Take a barrowful of sand and pour a gallon of spirits of tar upon it by degrees, so as thoroughly to incorporate the whole mass, with the hands, and then sow it over the surface of the field intended for carrots. The above quantity will be enough for sixty or seventy square yards.

The object of uniting the spirits of tar with the sand is to divide it so minutely that a small quantity may be scattered over a large space; for it is believed that the scent is so offensive to insects, they cannot endure the soil where it is thus employed: under these circumstances the female flies would avoid such localities, and in all probability the spirits of tar would kill the young larvae if even they hatched.

Some cultivators have applied this dressing in the autumn, digging it in and letting it remain until the carrots were sown, whilst others have tried it after the sowing. When it is dug or ploughed in during the autumn, it is supposed to drive the vermin to the surface, where they perish; and if repeated in the spring, after sowing, it no doubt renders the surface disagreeable to the flies.

2. Millipedes and Centipedes:

The Polydesmus complanatus is attracted to the roots which have been previously perforated by the maggots of the Psila, and sometimes congregated in such vast numbers. It may, however, be added, that these Millipedes are said to crawl about the surface before sunrise, when then have been collected into cans by myriads and destroyed. A Centipede, named Scolopendra electrica, often accompanies the Polydesmus, and assists in such depredations.

Papilo Machanon-The Swallow-Tailed Butterfly:

This is the first to be noticed; but it is an insect so far from common, being entirely condoned to certain localities in this country, that it is rather with a view of completing the history of the carrot insects, than from any necessity of guarding the agriculturist against its inroads, that it is introduced. It is, however, abundant in France, where the grace full evolutions of the Swallow-tailed butterflies may sometimes be seen even in the gardens of towns.

As England is being better drained, many native insects are expelled from their ancient haunts, and are becoming extinct in some districts: this is the case with Papilio Machaon, whose geographical range has been greatly circumscribed by cultivation short period. Some fifty years back, this conspicuous butterfly appeared annually in neighborhoods where now it is never seen.

The female butterfly will lay her eggs indiscriminately upon the leaves and flowers of carrots, the marsh mild-parsley (Selinumpalustre), rue or fennel, in the end of May and in June. The caterpillars of various sizes and colours may be found feeding in June and July; and the butterfly is sometimes seen until the middle of August.

The caterpillars are black when first hatched, which colour they retain until they are half grown, being then ornamented with spots and rings of green, with warts producing minute brushes of bristle when arrived at maturity they are nearly 2 inches long, and as thick as a swan’s quill; they are then beautiful objects, being quite smooth, of a charming green colour, with black velvety rings, upon which are orange warts, excepting the alternate rings, which from a junction with the segments, and are often concealed when at rest.

They have six black pectoral legs like horny claws, eight fleshy abdominal feet, and two similar anal ones for holding firmly; but the most curious distinction in the structure is a forked apparatus, like Y, of an orange colour, inserted behind the horny head, which the animal can thrust out or withdraw at pleasure; and this organ, which secretes an acrid fluid of an offensive scent, is believed to drive away the Ichneumons and other parasitic enemies, which would otherwise annihilate such a conspicuous species.

It is generally in July that the transformation to the chrysalis takes place, when the caterpillar fastens its tail, spins a tread across its back shoots off its skin, and assumes a yellow or green tint, with an interrupted black stripe on each side. The butterfly is the largest and finest species produced in this country, belonging to the Order Lepidoptera, the Family Papilionide, and the Genus Papilio.

Papilio Machaon, and is called the Swallow-tailed. Butterfly from the two appendages which emanate from the hinder wings. It is yellow, with black horns the head, turned, and body are black, the sides striped with yellow the upper wings have a large black space at the base freckled with yellow, the hinder margin is black with a line of yellow crescents; the nervures from black stripes, and there are three largish black patches above the disk; the lower wings have a broad black border with yellow crescents along the margin, and there are six freckled blue patches upon the back, with a brick-red eyelike spot at the anal angle, and a blue crescent above, the whole in-closed in a black ring; the tails are black with a yellow edge inside the wings expand from 3 to 3½ inches.

Carrot and parsnip crops when left for seed are dreadfully injured by multitudes of rather small caterpillars, which roll up the leaves, spinning webs amongst the flowers and capsules, to enable them to feed in security, leaving nothing but the stalks and fragments of the fructification to reward the owner. This is so great a loss that it is well worth attending to; and by becoming acquainted with the habits of these insects, no doubt their ravages may be arrested.

Depressaria Cicutella-The Common Flat-Body Moth:

A vulgar name which it has received from its depressed abdomen, to which also the Latin generic name alludes; and the scientific specific one is no doubt applied from its inhabiting a cow-bane named Cicuta, one species (C. virosa) being a very abundant plant in our ditches: the caterpillars are also found upon the wild chervil (Cherophyllum sylvestre) and gout-weed (Aegopodiumpodagraria), weeds equally abundant in our hedges.

These are all Umbellifere as well as the carrot (Daucus carota), about which the moths are usually seen flying to extract honey from the flowers, The common flat-body moths seem to be domestic species, for they enter our houses and are often mistaken for clothes-moths, from their frequenting rooms which are seldom used, and are seen upon the curtains, walls, and windows of our sleeping-rooms in the evening.

They endeavor to avoid the light, running about with much activity, and gliding over the surface until they can find a quiet corner to conceal themselves in. They also fly well and rapidly; and the females, which live through the winter, lay their eggs upon the flower- heads, or umbels as they are called, or in the axilla of the leaves, for in June the caterpillars are large enough to be discovered, and immediately cut the leaves of the chervil or carrot to band and from them into little tunnels, which are held together by threads; in these they reside, feeding as it were upon the walls of their habitation, and when these are consumed they remove to another leaf, which is rolled up in the same way.

Each end is left open to allow the caterpillars, when they are alarmed or disturbed, to fall to the ground by a thread proceeding from the mouth. This is necessary to enable them to escape from their natural enemies, amongst which are the Solitary-wasps (Odynen), which fill their cells with this kind of caterpillar to support their young.

They are exceedingly active, wriggling backward and forward, and jumping from one side to another, when touched, as if in convulsions they are 182 inch long, of a grass-green colour, with a darker green line down either side and one along the back; on each segment are ten warty black points, four disposed in quadrangle on the back, and tree obliquely on each side: the head is brown with two brighter spots of the same colour; the thoracic scale is brown with a broad black margin, and they have sixteen green legs.

When they are ready to change to pupae they become rosy beneath, very restless and continually wander about as if sending for food. Sometimes it appears the entire earth to change to pupae, where they form little oval cocoons of grains of sand, loosely attached by silken threads, the inside being lined with silk, or they undergo their transformations in the habitation formed in the leaf. The chrysalides are of a deep yellow brown, and shining. There are two broods annually; the June one hatches in August and the caterpillars found the first week in September become moths in the end of October, and they hybemate.

D. cicutella is supposed also to be the Pyralis applana of Fabricius. It is of a dull pale reddish ochre colour, and shines like satin: the eyes are small, black, and orbicular; the horns are long and slender, and the palpi or feelers are curved upward like short scaly horns, but the apex appears naked and pointed: the trunk is orbicular, the body depressed, the tail tufted with ochreous hairs in the male, lanceolate in the female: the wings rest flat upon the back in repose, one lying over the other, (a. the natural length); the upper wings are long and narrow, freckled with brown and black, forming indistinct spots upon the pinion edge, along which is a light streak; on the disk are three white dots with dark edges, and two brown dots nearer the base: the under wings are yellowish gray, very satiny, with a longish fringe.

Depressaria Depressella-The Purple Carrot and Parsnip Seed Flat-Body Moth:

Variety was figured under that name by Hubner, in which the pale marks on the upper wings were entirely wanting, and this led me to publish it under another appellation this species is less generally distributed than D. cicutella, yet it is abundant enough in some districts. It is confined to the more northern latitudes.

It is astonishing that this species, so injurious to kitchen garden plants, should be so little known and in so few collections, finds it by thousands. It also inhabits the wild parsnip (Pastinaca sativa), along the shores of the Thames, especially around South end, where it was found and bred from the caterpillar by the late Mr. E. Blunt and Mr. C. Parsons. There they also change to pupae in a light gray web.

In the autumn the habits of the caterpillars are somewhat altered, for they eat into the stalks, to winter there and undergo their transformations. Early in the spring, or even at the end of winter, if mild weather prevails, the moths hatch, come out of the hole in the stalk, previously made by the entrance of the larva, and fly about; but on the return of cold or bad weather they shelter themselves in holes, thatch, out-houses, under loose bark, in chinks of trees and paling, under stones.

Depressaria depressellavaries in the size of the sexes: the male only expands 6 inches, it is of yellowish mouse-colour and silky; the horns are not long; the round eyes and tips of the recurved palpi are black, die latter are ochreous at the base; the head and thorax are also ochreous; the tail is blunt; the upper wings are of a chestnut colour with pale ochreous scales on the disk, more or less visible, sometimes wanting, at others forming patches.

The wings of the female expand 8 or 9 inches, and are similar in colour to the male, but the upper ones are generally brighter chestnut, and the whitish scales unite and form a somewhat irregular oval mark, open at the top; the tail is pointed.

Although the caterpillars of this species are very abundant on carrot- seeds, they prefer the parsnip, which has induced gardeners to set parsnips amongst carrots left for seed, in order to attract the moths to them, so that the caterpillars may be more readily collected and destroyed. Bouche has never observed this species upon the common cow-parsnip (Heracleum sphondylium), which is a favorite resort of some species.

It may be advisable to add his description of the caterpillar, which resembles that of D. daucella, but it is much smaller: the ground ­colour is pale brownish grey; it is rough with black spines producing single hairs; the hairs have large white basal warts, which are arranged like those of D. daucella- sides of the body with inflated edges spiracles black head, thoracic plate, and pectoral feet deep black: abdominal feet having the soles furnished with a ring of hooks: length, 3½ inches.

Depressaria Daucella – The Grey Carrot-Blossom Flat-Body Moth:

This is a third species of the same genus of Moths whose caterpillars consume the flowers and seeds of the carrots and parsnips in July and August, causing great damage and sometimes destroying the entire crop; each caterpillar taking possession of an umbel of flowers, which it draws together in the center by the fine threads that are spurn from the mouth; in the midst of this resides the active wriggling caterpillar; which is at least ½ inch long when full grown of a greenish grey colour, inclining to yellow, with minute black warts, emitting short hairs scattered over the segments there are also indistinct longitudinal streaks down the back; the horny head and back of the first thoracic segment are brown or black. Some change to pupae amongst the web and stalks of the umbel, whilst others bore into the stems to undergo their metamorphoses. The pupa is dull brown with pitchy limb-sheaths, very finely punctured.

The Moth, named D. daucella, after the carrot, is ashy grey: the horns are like slender threads; the palpi or feelers are curved upward the head and thorax are reddish brown, freckled with black: the upper wings are also reddish brown with white atoms scattered over them, and black interrupted lines forming streaks and dots along the nervures, especially towards the hinder margin; the underside of the upper wings is dark; the under wings are light grey: it expand 10 to 11 inches.

There are several modes of arresting the mischief which all the caterpillars of these moths occasion, we have stated that the larvae are very sensitive, and fall down by a thread when disturbed: if therefore the flower and seed heads were shaken over a sieve, with a piece of paper at the bottom to prevent their escaping through the apertures, garden crops at least might be freed from them.

The best process, however, for banishing the D. daucella, which is perhaps the most mischievous species, has been suggested to M. Bouche from a knowledge of its economy. He has ascertained that the moths prefer laying their eggs upon the parsnip; he therefore plants in his carrot fields parsnips at 6, 8, or 10 feet asunder, which attract the moths; the eggs are consequently deposited upon them, and the caterpillars will not abandon the umbels on which they were hatched for those of the carrot.

By this simple measure he finds, at the time for gathering he carrot-seed that it is not only preserved from the attacks of the caterpillars, but also, being all attached to the parsnip-heads, by collecting and burning them, these troublesome little pests may be nearly eradicated.

He justly observes, that this operation must be cautiously performed, otherwise the lively caterpillars will fall out and escape; to prevent this, on approaching the; parsnip plant, the infested heads should be instantly bent over a sieve or tub, and cut off, so that the contents may be burned without loss of time; or he proposes that the parsnips might be left until the caterpillars were changed to chrysalides; but this would be dangerous delay, if any of them descend and enter the earth to undergo their transformations.

If they all become pupa in the umbels or stalks the proportion is a good one, but such, is not invariable the case. These caterpillars are not free from parasitic enemies; indeed two have been bred from those of Depressaria daucella by Bouch. They both belong to the Order Hymenoptera, and Family Ichneumonide the first is comprised in the Genus Cryptus or Phygadeuon.

Cryptus (Phygadeuon) Profligator:

It is black; the abdomen oval, red; petiole narrow and black; legs stout, shanks and thighs red, apex of the hinder thighs black in the male horns of female with a white ring four wings, transparent or slightly smoked, stigma rusty; areolet five-sided: abdomen dilated towards the apex in the female; ovipositor one-third or one-fourth as long as the body; length from 2 to 3½ inches. This Ichneumon is found on umbelliferous flowers, and the female deposits her eggs in a great number of the caterpillars of Depressaria daucella.

Ophion (Pristomerus) Vulnerator:

It is black, with the middle of the body red: anterior legs red, black at the base, hinder red and black alternately; the thighs with a tooth beneath, ovipositor black, oviduct chestnut colour; scarcely as long as the body: length 2 to 3½ inches.

This parasite is also often concealed in its maggot state in the caterpillars of D. daucella and. other kindred species; both sexes frequent the parsnip when in flower, in the beginning of July.

The vast percentage of our vegetable produce which is consumed, not by man, but by insects, those almost unobserved visitors, is really incredible. In a wild state of nature their services are most important in reducing the super-abundance of rank vegetation; they are not only the scavengers, but the labourers, whose unceasing industry thin the crops and keep both trees, shrubs, and flowers from something on another with their luxuriance; at the same time they are manuring the soil and rendering it more productive and more speedily applicable to the wants of the human species but when the soil is subjected to the skill and industry of man, and the produce is to be the reward of this anxiety and labour, the farmer and gardener consider, naturally enough, that the services of a great many insects might be dispensed with, advantageously to themselves and no doubt with benefit to the public.

Before attempting to wrestle with such insidious enemies, three things are most essential – knowledge, industry, and perseverance. Wanting the first, we may do more harm than good by destroying our friends instead of our enemies: without industry the economy of insects can never be attained: and if we have not a great share of perseverance, the best conceived remedies may prove futile. “Practice with Science” in every department of agriculture must lead to useful results.

Callimome Dauci- The Carrot Gall-Fly:

When the carrots are in full flower, the umbels often appear distorted, and on examination on finds a number of small vegetable galls that are produced, it may be presumed, by the punctures of some Cynips or Cecidomyia when the eggs are laid. It is a very singular fact, but there are a few groups of files, which have the power of causing a derangement in the sap-vessels, and an extravasation of the fluids, giving rise to excrescences assuming the most remarkable figures.

The greatest numbers are formed upon the oak, one of them being the gall of commerce; other are the oak apples, and the bedeguar, or moss like Balls upon the stems of dog-roses, which must be known to everybody. These are all the creations of different species of cynipes, but a beautiful little fly of the same genus as the carrot gall-fly is also produced from them, which is no doubt a parasite.

The female Callimome is furnished with a slender oviduct as long or longer than the body, this she insinuates through the cuticle of the plant, to deposit her eggs in the maggots of the cynips, which reside in the centre of the galls, where they undergo their transformation to pupa, and subsequently the flies are hatched and emerge from a hole in the gall, excepting those which are inoculated by the Callimome.

These beautiful flies belong to the Order Hymenopetra, the Family Chalcididae, and the Genus Callimome.

C. dauci, from its being bred form the carrot. The male is of a brilliant metallic green; the horns are thirteen-jointed and black, basal joint green; the head is short and broad, thickly punctured; the compound eyes are lateral and orbicular, the simple ones form a broad triangle on the crown; the thorax is oval and punctured the sections deeply marked: the abdomen is smaller than the thorax, somewhat spindle-shaped, very glossy, scooped out at the base, the apex with a short horny process: the four wings are as transparent as glass, but iridescent; the superior have an ochreous nervure along the costa, which terminates beyond the middle in a little dot: the legs are straw colour, the coxac and thighs are metallic green, the apex of the latter ocherious: hinder shanks pitchy, excepting the base and apex; feet five-jointed hips black, terminated by minute claws and cushions: length, 1¼ inches; expanse, 2½.

Female larger; 1½ inches long, ovipositor ¾ inch long: magnified bright green like the male the horns are also black, but the long basal joint is straw colour with a dark streak on the back the abdomen is not concave at the base, and it is terminated any a ling ovipositor composed of an oviduct in closed between two black hairy sheath: the legs are coloured like those of the male.

It would scarcely be possible to eradicate these insects without destroy in the seed-crop, and as it is almost certain that they are the destined check upon some cynips or, Cecidomyia which first creates the galls, by burning the infected umbels our friends would fall victims to such a measure, as well as the actual offenders.

3. Tephritis Solstitialis:

This beautiful fly is abundant on thistle blossom during the summer, and being named by Fabricius T. dauci, which implies that he had reasons for believing that it was connected with the carrot crops.

T. Solstitialis:

Its head and horns are reddish ochre; eyes green; thorax olive green; scutellum yellow; abdomen black, with a long black horny oviduct in the female; wings with two or three smoky bars, and the apex is margined with the same; legs ochreous: length of male 1-3/4 inches; of female, 3 inches, Parsnip roots do not seem to suffer any very material injury from the insects which attack them and their allied neighbor the carrot, and they may be grown successfully upon a heavier soil.

The inroads of the larval do not destroy the flavour of the parsnip, as they do of the carrot: neither do parsnips falls a sacrifice to the Aphides, nor are the young plants carried off by wireworms, caterpillars, or the maggots of the crane-fly (Tipulaoleracea). The leaves are frequently blistered by the same insect which infests celery lives.

Tephritis Onopordinis-The Parsnip and Celery Miner:

Tephritis is a group of lively flies, which delight in the sunshine, when they run fluttering over bright leaves, vibrating their beautiful spotted wings, which are carried erect, somewhat like those of the butterflies. About fifty species inhabit this country, but with the exception of T. onopordinis another named T. artemisie, whose maggots mine the leaves of the garden chyrsanthemims, and possibly T.solstitialis, alluded, there are none that are guilty of any injury to cultivated plants.

T. Onopordinis may be seen in sunny days in gardens, hedges, at the skirts of woods, or wherever such flowers grow as are an agreeable resort for the males. The female runs over the leaves of the celery and parsnip, and with her telescopiform oviduct she no doubt pierces the cuticle and deposits her eggs, apparently singly; these hatch and produce little transparent maggots, which feed upon the parenchyma, or pulp of the leaf, causing large blisters upon them; and when two or three larvae are feeding on the same leaf, the blisters unite and form large discoloured patches, for the inflated skin, which at first is pale or whitish, as it dries becomes yellow or tawny, and the maggot may be distinctly seen when the leaf is held up to the light.

Thus the leaves are disfigured from midsummer to near Christmas and as the maggots arrive at maturity, they either change to pupae in the blisters amongst the excrement of the larvae, or pierce the skin.

Falling upon the earth, undergo their transformations in the soil, and form these the flies are again produced. These two-winged flies belong to the Order Diptera, the family Muscidae, and the Genus Tephritis.

T. onopordinis, from its frequenting the cotton-thistle (Onopordum acanthium). It varies in the spots of the wings which has led the same author to describe a variety under the name T. centaurea, from its resorting to another genus of composite flowers. The larvae, are nearly 4 inches long, shining pale green; they look fat and somewhat transparent, so that the alimentary canal is visible along the back, forming a darker line magnified it is attenuated to the head, which is pointed, and the tail is blunt and tubercle; the body is divided into segments, and the sides are wrinkled.

The chrysalis, is horny, pale yellow, glossy, and oval; the segments deeply impressed from the contracting of the maggot, of which this is only the indurated skin, for maggots do not cast their skins as caterpillars do. When one of the pupae was opened in February, a delicate nymph of a beautiful green colour was seen inside; and when the fly is perfectly matured, it elongates its body, which is filled with a thick cream -like fluid, or meconium; the pupa-case cracks at the head, and through the opening the fly walks forth.

T. Onopordinis:

The male is about 2 lines long, and the wings expand 5 or 6 lines; it is shining, tawny, white a few black bristles scattered over the head and thorax; the lower part of the face and the two little dropping horns are yellowish; the latter -jointed, with a black bristle ochreios at the base, attached to the back of the third joint, which is oval; at the lower part of the face is a large cavity to receive the mouth, which is composed of a fleshy hairy bilobed lip, two long hairy fleshy feelers, and a short strong horny pointed tongue; the lateral compound eyes are remote, ovate, and deep green; and there are three little simple eyes forming a triangle on the crown upon a dark spot trunk ovate the scutel semi-ovate; abdomen somewhat oval; wings ample, iridescent, transparent, varie-gated with brown, forming spots of various sizes; poises small, clavate, and ochreous legs six, ochreous with short black hairs: feet five-jointed, terminated by two small claws and two lobes or pulvilli between them.

Female larger, abdomen broader, with a longish retractile ovipositor. In some varieties the trunk and abodomen are pitchy. Securely as the maggots of these flies mine beneath the surface of the leaves, there are two little parasites which fly and run about to detect them in their habitations, and by depositing their eggs in them they arrest the multiplication of the Tephrites to a considerable amount. They both belong to order Hymenoptera, but one is o the Family Ichneumones adscii; It is included in an extensive Genus called Alysva; and from its having been produced in the first instance from blistered celery leaves (Apium graveloens).

A. Apu:

It is pitchy black and shining; 1½ inches long; the wings expand 4 inches; the horns are like slender pilose threads, longer than the whole body, and composed of a multitude of little joints; the first joint rust-coloured beneath, the little second joint entirely ferruginous: head large and broad, with two small lateral eyes, and three simple ones forming a triangle on the crown; mouth with an upper and under lip, the latter with two four-jointed hairy feelers; there is also a pair of tridentate spreading jaws, and two hairy lobed maxille, furnished with very long slender six-jointed hairy feelers: the trunk is elongated and oval; the body is broader, oval, pitchy, seven or eight jointed, and rough at the base, where it is very much narrowed, the second segment is sometimes rusty at the base: it is depressed in the males, but slightly compressed in the females, with a short, scarcely visible ovipositor; four wings very iridescent and pubescent; superior very ample, with one large marginal, three sub marginal, and two small discoidal cells; stigma very long and slender smoky, and terminated by minute claws. These little Ichneumon-flies were bred in June from the pupa, and were abundant about thirty years since, but I never meet with them now.

The other parasite is included in the Family Chalicididae, and Genus Pachylarthrus: it is named by Mr. Haliday, from its brilliant emerald colour.

P. Smaragdinus:

It is only 1¼ inches long, and scarcely expands 3 inches: it is of a charming green colour, thickly punctured: the male has bright ochreous horns, composed of thirteen joints, the basal one very long, the third and fourth exceedingly minute: the maxillary feelers are terminated by a large oval orange joint the head is broad, the compound eyes are black, with three little simple eyes in triangle on the crown; the trunk is obovate and not so broad the body is still narrower, small, oval, and of a metallic luster; the base is contracted, and at the extremity is a curved horny sexual organ; the four wings are transparent; superior ample nerveless, excepting a costal nervure, which forms a short capitate branch beyond the middle six legs clear ochreous, coxae green; feet give -jointed, tipped with brown. Female larger, blue green; horns black; feelers not incrassated; abdomen larger, with an oviduct concealed beneath; legs ochreous white; thighs green, excepting their tips; middle of shanks brown: tips of feet black.