Pests that Damage Vegetables | Zoology

Here is a list of pests that damage vegetables: 1. Tipulae or Crane-Flies 2. Wireworms 3. Centipedes or Sclopendre 4. Tyroglyphus Farinae 5. Lithobius Forficatus, the Thirty-Foot 6. Geophilus Lingicomis 7. Oxytelus Nitidulus 8. Potato Files 9. False Scorpions 10. Worms.

1. Tipulae or Crane-Flies:

Any one may readily imagine what an amount of vegetation must be consumed by the maggots or larvae of these gnats seeing that during the summer and autumn it is not possible to step on a field or meadow without disturbing a family of the winged parents. Indeed, turnips, potatoes, beet, carrots, and cabbages often suffer as severely from the attack of Surface-caterpillars, the larvae of Crane-flies, and the Wireworms, as from any other insects.

From the beaked head and attitude of the body and legs in flight, the Tipulae have been termed Crane-flies, but in some counties they are better known by the name of Daddy of old Father Long legs. As it is mostly in undisturbed ground that the larvae are propagated to any extent, it is most desirable to keep land clean.

Of course weedy banks and hedge-rows will naturally be a harbor for them, as they delight to live amongst the roots under tufts of grass, but their head-quarters are damp meadows and marshes. Wet, consequently, encourages them, and to drown them is impossible; therefore, the opposite course, of draining land effectually, would do doubt annoy them more than any other process, and go far towards freeing arable lands, at least, form these universal pests.

The eggs are laid by the females, as they fly, or when they rest, amongst the herbage, and are propelled as from a pop-gun. Those of Tipula oleracea are little oval conical grains, shining and as black as ebony; they form a mass occupying nearly the whole abdomen. The little maggots hatched from these grow until they are as thick as a small goose-quill, cylindrical, and about an inch ling: they are then of an earthy colour and incased in such tough skins that they are called “Leather-jackets.”

The intestines shining through the back create two pale wavy lines, in which a pulse is very evident. When walking or wriggling along, for they have no feet, they protrude their little black horny heads, stretching out the neck, which then tapers, and exposing two minute rust-coloured horns and two strong black jaws; when in motion their tails are thicket and cut off abruptly, the edges above being furnished with four fleshy tubercles more or less pointed, with two below, and near the center are two spiracles or breathing pores; they are composed of thirteen rings, and when drawn up and at rest look like small boats.

From the beginning of May to the first week in August these larvae have been observed at the roots of scarlet beans, lettuces, beet, and potatoes; and during the same period they are most unwelcome visitors in the flower-garden, where they commit dreadful ravages amongst the roots of dahlias, carnations, &c., and even the grass-plots in the metropolis do not escape, for in Golden Square a few years since the grass was laid bare by them.

It is said they come out at night in multitudes to feed, and probably to remove from one locality to another when food becomes short, or it may be in search of convenient places to change into pupae; at all events they are then secure from the rooks and smaller birds, which would speedily thin their ranks, and the dews of night suit their purpose in every way better than the light and heat of day.

Some of the forwarders change to pupae early in August, perhaps in July, and certainly in September, this takes place under the turf, and even by the sides of gravel walks, if the weeds be left to grow: they are as long and thick as the larvae, of a similar dirty colour, with two slender horns, one on each side of the head.

The segments under the belly produce transverse rows of stout spines, and smaller ones on the back; the tail is pointed and spiny; on each side of the trunk are the cases containing the wings, and between those which enclose the legs, after remaining in this state a short time, the pupa by means of these spiny rings, works its way through the surface of the earth, the horny covering of the trunk splits down the back, and the gnat crawls forth to dry its wings and harden its limbs, before it takes flight to pair and generate new families. At this time thousands of empty cases may be seen sticking half out of the earth amongst the grass. The Crane-flies belong to the Order Diptera, die Family Tipulidae, and the Genus Tipula.

T. Maculosa:

The male is not ½ an inch long; the female is more, and the wings expand about 1 inch. They are of bright yellow colour, spotted with black- the male has a pair of slender blackish horns longer than the thorax; the forehead projects like a cone, on each side is a black dot, and on the crown is a black spot pointed over the forehead, the mouth is at extremity of a cylindrical beak, the feelers blackish; the eyes are black, as well as three long patches on the back of the thorax, and various spots on the sides and beneath.

The scuttle has a conical mark on the back, with a black hinder margin: the abdomen is slender, the apex obtuse, with a broken line of eight black spots down the back; on the under-side is a similar line, as well as several black dots at the base- the wings are smoky-yellow, and iridescent, with brown nervures, a yellow pinion edge, and stigma; the two balancers are ochreous and clubbed: the long and very slender legs are ochreous, the extremities of the thighs, shanks, and the very ling feet are black.

The horns of the female are shorter the abdomen is longer, spindle-shaped, with six distinct, black top-shaped spots down the black, row beneath, and several dots on each side- the horny ovipositor is ochreous and shining, these gnats are abundant in fields, gardens, meadows, hedges, &c. during May and June. Sometimes they swarm on the sea-coast, and in the middle of May seeing myriads on the sand-banks in the Isle of Portland, also at the back of the Isle of Wight, and at Lowest in Suffolk.

Many insects are driven apparently by the wind to the edge of the sea, where possibly their course is arrested by a sudden change in the wind, and they perish in the surf; but no doubt multitudes thus collected escape and generate in the surrounding country. There must be two or three broods of T. maculosa in a year, or else a constant succession of the flies during the summer, for although the month of May seems to be the period when the greatest numbers are hatched.

Many different species of Tipulaeaxe bred in the field and garden, but the destructive maggots so greatly resemble each other, that they can only be distinguished by actual and careful comparison. A very similar larva is most abundant in the gardens of London, which produces an allied gnat, named by Meigen Tipula quadrifaria.

The eggs of T. maculosa are oval, spoon-shaped, and black as soot. They must be scattered over the ground as thick as poppy-seeds, for probably not one in a thousand arrives at maturity. The larvae produced from them are of the same earthy colour as those of the Cabbage.

Crane-fly, but they are smaller, being only ¾ of an inch long, and as chick as a large crow’s – quill; they differ also from them in the position and form of the spines; they are wrinkled, and when at rest contract themselves, drawing in the head and thoracic segments, so that this extremity might be taken for the anal end.

They are, however, able to thrust out their heads and crawl along very well, although they are destitute of feet; the small brown head is furnished with a pair of black jaws, two short horns, and I believe minute feelers: three pale vessels traverse the sides and back, terminating in a truncated tail with two spreading hooks, and two short teeth between, with two tubercles below, and two fleshy protuberances capable of dilatation and contraction, which materially assist maggots in locomotion, and in the center of the stern are two large spiracles.

In the spring they change in the earth to pupae of the like dirty colour; these are about the same length as the larvae, but scarely so stout. At this period the head and thorax of the future gnat are defined, but from each side of the latter projects a short slender horn, and beneath the horny case the incipient wings are visible, with the legs placed between them the abdominal segments have each a transverse row of minute spines above, and five large ones beneath, and on either side is an elevated spiny line; the penultimate segment is surrounded by six longer spines and two small ones, with a large conical process at the tail and a shorter one beneath it.

Dickson advises, “When the grub is abundant, to roll the land be times in the morning in the early spring months, which may crush and destroy them; and when the fly abounds in summer evenings on grass lands or fallows, rolling would destroy them and prevent the deposition of the eggs: they are chiefly deposited in the long grass, on sides of hedges and ditches- such places should therefore be kept free from weeds”.

He also recommends “keeping the clover stubbles closely eaten down by sheep or other animals, after the hay has been taken, till the wheat-crop is nearly ready to be put in, which has been found in some measure an effectual remedy against the destructive attacks of the insect”. Children and women might also be employed very advantageously in destroying the parent flies, by hand-picking and sweeping with nets.

The farmer must also encourage such birds as render him good and constant service in reducing the insect tribes. Amongst them the rooks and starlings, seagulls and lapwings, are most faithful allies, and labourers worthy of their hire. Pheasants also must feed largely upon them in the winter, they were alive, and nothing else was found in the crop, excepting a few oak spangles.

A correspondent also of the Sporting Magazine writes, “That no fewer than 1225 of these destructive larvae (wireworms?) were taken from the crop of a hen pheasant in January”. No doubt these birds pick out the larvae in corn and turnip fields, and when it is remembered, that the almost incredible numbers contained at one time in the stomach, only made a single meal, the extent of their services may in some be estimated.

2. Wireworms:

As no crop is perhaps altogether free from these destructive larvae, we need not be surprised at their inroads upon the potatoes; indeed wireworms seem to be especially fond of them, since there is no better trap than slices of potato stuck in the ground and covered with earth, to be examined daily. In this way every wireworm may be attracted from a flower-bed and destroyed.

A potato-crop is ever entirely destroyed by wireworms, although when young they hire up into the haulm, as observed by Mr. Graham, and the sets also are stated to have been greatly injured by them in May; but they undoubtedly diminish the value of the tubers materially by perforating them, and thus rendering them a suitable nest for other insects. Towards the end of September, the potato crops were greatly infested in some localities by wireworms, millipedes and centipedes.

A gentleman has suggested that potato crop may even attract the wireworm. It appears from our correspondent, that in 1844, in order to clean and redeem seven acres of exhausted land, it was planted with potatoes after oats: the potatoes did not suffer from the wireworm; the crop was good as could be expected, and considering that the great dryness of the season had delayed the planting till June.

In March, six acres were sown with oats, and acre having been dibbled with wheat in December. The crops were most healthy, but subsequently patches of decay attracted attention, and it was soon found that the wire worm had been at work to so fearful an extent, that in ten days the whole crop seemed victimized.

Soot was then applied to four acres (sixteen bushels per acre), and not being able to obtain more, the remainder was sown broadcast with guano, at the rate of two cwt per acre, all applied in a pouring rain. This arrested the evil, and many of the patches apparently destroyed, struck up a second growth from about ½ an inch below the surface, where the wireworms and bored through the shoots, and the oats eventually became the best crop in the parish.

The tubers left in the ground attracted them to certain spots where they perforated the potatoes and caused their decay. If, therefore, these potatoes could have been collected before the oats were sown, the crop would have been saved from their incursions. When the first crop of oats was grown, they were probably too young to commit much if any apparent mischief, they came from any distance; if such were their habits, they must ere this have been observed when migrating at night. These remarks of Mr. Duncombe also show the value of soot in recovering crops from the attacks of the wireworms.

Wireworms are very common, and Metz great numbers have been found by M. Rayer the inspector of agriculture, both in sound and diseased potatoes. It is worthy of remark that they are a very different wireworms to our common one, being more like that of Elater murintis and E. lineatus, clearly showing that various wireworms feed upon potatoes, all of them making numerous holes and burrows in the tubers, both causing and hastening their decay.

Snake Millipedes:

Snake Millipedes are found in large numbers in potatoes, as soon as symptoms of decay appear, especially in September, and they consequently complete the destruction which the wireworms began, lulu’s londinensis and I. terrestris are two of the snake millipedes which are said to be injurious to early crops in the winter.

During frosty and cold weather they lie curled up in the earth, but so slight a degree of warmth is required to awaken them from their torpor, that by merely breathing upon them for a few seconds they awaken from their slumbers, and move about with their accustomed gliding gait.

They seem to congregate in autumn, and as they are very fond of fruit, vast numbers may be collected by putting slices of apples under tiles or in baskets of moss: upwards of forty have been taken from one slice: but these modes of catching them can only be practiced in gardens; I expect, however, if cabbage leaves were scattered along the furrows in damp weather, that they would be nearly as attractive. The most abundant and mischievous species is the lulus pulchellus, called Blaniulus, from the indistinctness of the eyes or their entire absence. It was reported to have destroyed the potato-sets.

3. Centipedes or Sclopendre:

A large amount of these curious animals inhabit the earth, Lithobius forciputus and Geophilus electricus being the most usually met with. The former of these is said to be entirely carnivorous, and the latter will attack allied species as well as each other. Such being the case, they are probably useful in reducing the ranks of the various soft larvae which affect the roots of plants. It is certain that they are very abundant in potato grounds and Mr.

Hope attributed the potato disease to the attacks of the wireworms, and also to a small Scolopendra, which he had found in myriads infesting diseased potatoes, the Geophilus electricus was running about in every direction when the potatoes were forked out.

Vast quantities of the sound tubers had been perforated by the wireworms, some of which were found inside, and the cavities were often enlarged by slugs. These animals, which like the millipedes, are not true insects, belong to an Order called Chilopoda, and to the Family Scolopendriae. They were all included by Linnaeus in the Genus Scolopendra, but from variations of structure one is now called.

T. Paludosa:

T. paludosa implying its partiality to marshy ground- it is of the same size and colour as T. Oleracea, but the back of the abdomen is not of a state – colour, the wings are shorter in the female, as well as her legs which are also much shorter than those of the male. The males of the autumnal broods of both species first make their appearance about the commencement of August, and the females are abundant until they are killed by the frosts of autumn.

Even in the chilly mornings of October they may be seen, half stupefied by the cold, hanging by their forefeet, their wings covered with dew, and lying flat on their backs, until warmed by the cheering rays of the sum the male takes wing, and female drags her heavy body and ling legs after her as she flies through the grass. The males are attracted by light. Their great numbers come to a lamp at night in September, and the females have been observed at sea in calm weather many miles from land, standing on their legs, with the wings spread, sailing along unhurt.

A few appear to be hatched in the spring, and no doubt there would be more, were it not for the larvae furnishing rooks and many other birds with food during the winter and early spring. This is doing essential service, for in all probability these would produce the parents of the autumn broods, which, it is evident, are sufficiently numerous, not-withstanding the check upon their multiplication. Their numbers depend very much upon the seasons, and for this reason sometimes these troublesome larvae are not seen.

T. Oleracea:

T. Oleracea from its larvae injuring cabbages.It is of a tawny colour, with a bloom over it giving the fly a dusty appearance. The head is small, almost globose, attached by a short slender neck, the nose forming a stoutish rostrum or beak, acuminated at the apex and furnished with a short, fleshy, bilobed lip, and two longish five-jointed palpi; the eyes are hemispherical and black; the two slender horns are inserted in the face; they are as long as the entire head, tapering, and thirteen-jointed, the first longish, second globose, the remainder elongated and bristly, trunk large, oval, raised considerably above the head, divided into three lobes on the back, which is brownish with obscure stripes; under side hoary, as well as the somewhat orbicular- quadrate scutel body long, slender, and nine-jointed, clubbed at the extremity in the males, but it is much longer and spindle-shaped in the female, with the back slate-coloured; the apex horny, pointed, and furnished with two lateral tapering lobes, and an oviduct between them.

Two wings, longer than the body, spreading when at rest, rather smoky, with an areolet and seven cells at the apex; the nervures and a strip along the costa, including the stigma, ochreous brown; two balancers, long, slender, and clubbed: legs six slender, very long, especially the hinder pair, bright ochreous; tips of thighs shanks, and the terminal joints of the tarsi brown; the slaws are curved and acute, with minute pulvilli between them.

The male is nearly ¾ of an inch long, and the wings expand 1 ½ inch; the female approaches 1 inch in length, and the wings expand nearly 2 inches. There is another species so closely allied to the foregoing, that it is generally confounded with it: their habits and economy are similar, but they seem to be distinct, and it has been named by Meigen.

4. Tyroglyphus Farinae:

Tyroglyphus farinae being synonymous with the Acarus farince of De Geer – It is like a minute globule of fat, being of a pellucid shining white, with a rusty cloud on the back of some specimens, and it is not larger than very small grain of sand it is oval, the anus slightly concave; it has some longish rusty hairs scattered over the body, and the head and legs are of the same colour the thorax is small and but slightly indicated; the head and mouth from a horny cone the eight legs are short, stout, and tapering, the first and second pair incline forward, the former arise close to the head, the latter are attached to very large white escapes forming the base, the other two pair are inserted at the middle of the belly and incline backward; they are all six-jointed, the joints sub-quadrate or oblong, pilose, the penultimate producing a few long bristles and terminated by a strong hooked claw. They walk with tolerable alacrity and delight to burrow head foremost into the flour.

In the potatoes with the Acari were larvae of various little beetles which assist in reducing putrid substances to a simple state, which is indispensable for supplying the soil again with the proper elements as food for the support of vegetation. One of them was very similar to the larvae of a beetle called Demestes, but only 1½ line long; another, a little larger, would undoubtedly produce some beetles of the Families Carabidoe or Stapyhdinidae.

A somewhat similar larva was found in France which Guerin believes may belong to a Genus of little Rove- beetles, called Calodera. Another kind was detected by M. Raver, which is likewise supposed to belong to one of the Staphylinidae. Nests, also, of little creatures where found in rotting potatoes, which looked like black mites, but on close examination they proved to be beetles – members of a family entirely devoted to the consumption of putrid animal and vegetable substances.

5. Lithobius Forficatus, the Thirty-Foot:

It is nearly I inch long and 1-1/3 inches broad; smooth, shining, horny, of a ferruginous or ochreous colour, sometimes brown: it has two longish tapering horns, composed of upwards of forty minute joints: the head is large and orbicular, armed with powerful jaws like a pair of claws, having a small group of granulated eyes on each side: the body is flattened and linear, composed of sixteen plates like scales, alternately quadrate and narrow: it has fifteen pair of bristly and spiny legs, the hinder pair being the longest; they are seven-jointed, curved, tapering, and terminated by a minute conical claw: The other species may prove to be the true Scolopendra electrical of Linnaeus; it belongs to the Genus Anthronomalus of Newport, and is certainly Leach’s.

6. Geophilus Lingicomis:

This species is from 2½ to 3 inches long, and not more than ½ or 2/3 of a line broad. It is shining bright ochreous, the head is oval with a strong jaw on each side terminating in a sharp blackish claw: eyes none; horns thrice as long as the head, like two hairy threads, composed of fourteen joints, decreasing to the apex: body composed of a multitude of transverse segments, with from fifty-one to fifty-five pair of short legs, the hinder pair not longer than the other; the claws long and slender.

These creatures move with a very waving motion from right to left, doubling when they turn, and this, as well as a few other species have the very extraordinary power of secreting a phosphoric fluid, which the animal leaves behind as it walks, so that when it is dark one sees a luminous broken line of light, sometimes two or three feet long. This phenomenon is generally noticed in autumn and spring, and is supposed to be most active when the animals are pairing: whether the fluid is secreted by both sexes seems doubtful, and if they be quite blind, the light must be bestowed upon them for reasons which as yet remain hidden from us.

Their economy is likewise very interesting, for Mr. Newport has proved that “the female deposits her eggs, from thirty to fifty in number, in a little packet, in a cell which she forms for them in the earth, and never once leaves them until the young are developed, which is at the end of about a fortnight or three weeks. During the whole of this time she remains in the cells, with her body coiled around the eggs, incubating them and constantly turning and attending to them”. They hibernate in the earth during the winter, and subsist partly on succulent roots, ripe fruit, and decaying vegetable matter, only coming out at night, apparently in search of food.

We have now arrived at the second section of our subject, relating to the various insects and allied animals which are found amongst the potatoes when decomposition has commenced. They amount to a very considerable number, and yet probably not half of them have been noticed, for whilst those recorded by M. Guerin comprise nine different sorts, the species detected in this country are twice as many.

A Podura, probably the P. plumbea of Linnaeus, was abundant, skipping about the rotting potatoes, with its beautiful iridescent scaly coat, and in the cavities were numbers of a milk-white Ricinus, with multitudes of an ochreous A. cams allied to A. coleptratus. M. Guerin also describes and figures an Acarus called Glyciphagus fecularum, and another which he names Tyroglypus feculae a both of which were found in the changing potatoes or in cavities of the diseased tubers.

A. Minutus:

It is a little oval, convex, shining beetle, like a seed and not more than ½ line ling, often only 1/3: it is of a dark chestnut colour: the head is bent down, the feelers being visible but not the jaws; and in front are two short, curved, eleven jointed horns, terminated what oval club: the eyes are small and lateral: the thorax is very broad club: the eyes are small and lateral: the thorax is very broad and punctured; the scutel is invisible: the eytra are broad, semi-oval, not covering the rum; beneath them is folded a pair of wings: the six little slender legs line close to the body in response the interior shanks are flattened, and the five-jointed feet are short and very slender.

In the early spring these beetles are found under dung, and in September they have observed in ripe and decayed cucumbers in frame, where sometimes they are generated in thousands, the warmth favouring their increase. A still minuter beetle was detected amongst the potatoes, called Trichopteryx rugulosa; it is not larger than this dot, being scarcely visible to the naked eye, nevertheless its pair of horns and six legs are complete, and the beautiful wings with a long fringes are most marvelously folded up under the wing-cases when not in use. One of the species is very widely spread in the autumn, and lives through the winter: it is named by Gravenhorst Staphylinus nitidulus.

7. Oxytelus Nitidulus:

It is only 1¼ line long, narrow, flat, shining black, and coarsely punctured, the head is broad with several depressions, the oral organs are visible and the eyes prominent; before them are inserted the two horns, which are not longer than the thorax, thickest at the extremity, the first long and clavate, second small, third minute, the remainder like strung beads, increasing in size, the terminal joint ovate-conic, the thorax is broader than the head, somewhat semi – orbicular, with three channels down the back, the elytra are quadrate, chestnut-coloured, black at the base, and appearing striated from short depressed hairs, body nearly as the remainder of the insect, intensely black and glossy, elliptical, with seven district segments, the sides margined and pilose, the tail triangular, wings ample, folded beneath the wing-cases, six legs short and tawny, thighs thickened and rather pitchy in the middle; shanks flattened and serrated, excepting the hinder pair, which are slender; anterior notched outside near the apex; feet composed of three or four short and one long joint, with a pair of slender claws.

These insects are also found in decaying cucumbers, melons, and various vegetables; they frequent muck-heaps and breed in the dung of animals.

8. Potato Files:

Dead and silent as the earth appears to be, it teems with life; for not only is the soil full of seeds which merely required light the head to start them into life but it Just abound with the eggs of insects, so minute, that even with the assistance of a lens they escape one’s notice.

To be convinced of the truth of this, if a flower-pot be filled with mould from a field or garden, and then tied-tied over with the finest muslin, the experimentalist will be astonished to find the multitudes of little flies which are constantly making their appearance, bred no doubt from larvae nourished on the vegetable matter which such soils contain. Where crops are grown, and any portion of them becomes decayed, the number of these minute insects is vastly multiplied, and thus where the disease potatoes have existed, additional swarms of various little flies have been the consequence.

P. Nervosa:

The males are twice as large as the females: they are any white, clothed with longish wool, the little head is buried under the thorax: the black eyes are large and lunate: the two horns are as long as the thorax, and composed of eleven small joints, black at the base, giving them an annulated appearance. The abdomen is short and of a dirty colour, the two wings when at rest meet over the back slanting; they are iridescent, very large, oval and lanceolate, with numerous longitudinal hairy nervures, the entire margin is also hairy; balancers small, clubbed, and white six legs wholly; the feet five-jointed, the tips black.

In February, the larvae and pupae were abundant in the rotten potatoes, also in decaying leaves and dunghills, and the flies have been bred by Mr. Haliday from putrescent fungi. These flies sometimes swarm in outhouses and about drains in spring and autumn.

The larvae are not ½ line long, yellowish-white, cylindrical, spindle- shaped, with eleven distinct annulations besides the head, which is triangular; the tail is elongated and tubular. The pupa is about 2/3 line long, ochreous and ferruginous; it is elongate-ovate in response, but the body can be stretched out and attenuated when disturbed from the forehead project two slender appendages, like horns; on either side are laid the short stout antennae, and the wings meet over the breast, with the legs stretched out between them: the abdominal segments are ciliated and the tail is forked.

Several species of little swarthy two winged fly were bred from the decaying potatoes in multitudes. They are called Sciara by Meigen, and Molobrus by Latreille. The larvae are slender worms, about ¼ inch ling, whitish and opaque, but when immersed in water they become perfectly transparent, exhibiting the ochreous viscera and the food digesting in the stomach; when in notion they taper towards the head, which is oval, horny, black, and shining; the body is composed of thirteen segments, with seven or eight spiracles on each side; the tail is broad and rounded, but slightly pointed in the center.

The pupa is shorter, cylindrical, elliptical, and of a dull ochreous tint, becoming darker as the period approaches of the birth of the fly: the antennae, eyes, wings, and legs are visible beneath their horny sheaths. At this period they are deprived of locomotion, but the larvae, although perfect maggots, and destitute of feet, are able to move along in moisture, at the same time waving about and thrusting out their heads with great energy.

Sciara Fucata:

When alive it is 1 line long the natural length. The male is of a pale inky black, the head is small and spherical, with two triarticulate feelers bent under; the two horns are not longer than the thorax, tapering, pubescent, inserted in front of the face, and sixteen-jointed, two basal joints the stoutest, the remainder oblong, apex conical eyes lateral, kidney-shaped, and coarsely granulated; ocelli three, but unequal trunk gibbose, subquadrate, scooped out at the base, with two indistinct lines of short ochreous hairs down the back; scutel lunate, postscutel oval, of a greyish colour abdomen slender, greenish black, brownish after death, seven-jointed, the margins of the segments pale, apex obtuse, and furnished with two incurved biauriculate lobes two wings, incumbent in repose, parallel, longer than the body, iridescent, slightly smoky, but transparent and clear at the base, nervures brown, excepting the central one, which is scarcely visible, but forked and dark at the margin; the costal nervure does not reach the base of the forked cell: balancers pale dirty yellow or ochreous six legs, long, slender, and of a dirty yellow or pale olive tint.

Female are similar, but large, being ½ line long, the wings expanding nearly 3 lines: the thorax is not narrowed behind: the abdomen is spindle-shaped, attenuated, and conical, terminating in two little parallel sheaths: the two balancers are dusky when dry.

This was bred in the winter, in vast quantities: the flies are also found throughout the summer in fields and gardens, on umbellate flowers, and on grasses.

S. Punctate:

It is black and shining: the head is small; the eyes are kidney- shaped, with three little ocelli on the crown; the antennae are short, stout, cylindrical, and composed of eleven cup-shaped joints thorax elongated and somewhat compressed, with a white dot on each side; scutel small and rough; abdomen broad, oval and depressed wings ample, resting horizontally, transparent and iridescent, with a black costal, sub costal, and basal nervure, the first and second united beyond the middle, and divided near the base, by an oblique nervure; there are also four other very faint longitudinal nervures, the apical one forked, the anal one waved balancers yellowish legs simple, longish, and rusty; extremity of thighs and shanks variegated with fuscous; feet brown, five-jointed, terminated by a pair of minute claws.

The larvae from which these flies proceed, live in various putrid substances, and even in dung they have also been bread from the cocoons of silk worms, in all probability containing decomposing caterpillars or rotten pupae; they are from 2 lines to nearly ¼ inch long, flat, and narrowed at both ends, of a dirty greyish yellow colour; the head is brown and oval, with two short feelers the body is composed of twelve pubescent segments, the first thoracic one with a prominent spiracle on each side, as well as the penultimate, which with the apex is covered with radiating bristles.

The pupa is ½ line long, it is enclosed in the skin of the larva, a little depressed, and yellowish brown: from the thorax projects a branched spiracle, like buck’s horn, and the tail has .a shout spine. It remains from a week to a fortnight in this state, and the flies are often exceedingly abundant in the autumn.

S. Quinque-Lineata of Macquart:

S. quinque-lineata of Macquart is 1⅓ line long. It is black with five lines on the thorax of a deep dull gray anterior hips testaceous wings almost hyaline balancers brown or dirty white. Specimens agreeing with this description were bred from rotten potatoes in March, and sent to me with the tubers containing the larvae and pupae also. The potatoes were like old rotten cheese, and portions of the outside were covered with slimy threads, which Mr. Graham saw the larvae spin. He thinks they cause the “scab” in potatoes.

S. Pulicaria:

S. pulicaria is ½ a little long or upwards, and is distinguished from the two foregoing species by its longer antennae, which are equal in length to the rest of the body. It is black, with testaceous legs, the wings almost hyaline balancers brown.

Another dipterous insect was bread from the potatoes in less quantities it also belongs to the Family Tipulidae, and the Genus Scathope.

Musca Stabulaz:

The male is 3½ inches long, and the wings expand ½ an inch it is of an ash-colour, and clothed with black bristles; the feelers are ferruginous; the antennae drooping, five-jointed and rust-coloured, pitchy at the base, third joint elliptical and hoary, except at the base; the seta black and feathery, the basal joint minute, eyes large, approximating, naked, and chestnut colour, the margins silvery white, as well as the face, with a black stripe tapering from the antennae to the three ocellion the crown thorax hoary, with four black longitudinal stripes before, the two central ones the longest, with a spot on each side, beyond the centre; scutel hoary, with a dark stripe at the base, ferruginous at the tip abdomen ashy-ochreous, shining, the back variegated with brown patches wings with the apical cell not angulated, but suddenly rounded, scales at the base with pale tawny margins, and concealing the ochreous clubbed balancers: legs black, apex of thighs and tibiae ferruginus; pulvilli at the extremity of the feet elongated.

Female similar, but the eyes do not approximate, the face has a yellow tinge, and the stripe on the crown is broad and elliptical: the abdomen is broader, with an oviduct at the tail, and the pulvilli are small. The maggots had bred and accumulated amongst the slimy matter of the rotting potato just as meat-maggots are found, together with the horny pupae. Indeed, the largest maggots were exceedingly like those of the flesh-flies, being fat and whitish, the ochreous food and white lines of viscera shining through the transparent skin: the head was pointed with a black proboscis formed of two horny claws, and the two spiracles at the blunt tail were like two black horny knobs. The tough and oval pupae were of a bright chestnut colour, the segments slightly marked, the head end rounded and wrinkled to a point, the tail furnished with two black spiracular tubes.

Anthomyia Tuberosa:

The male is 2½ inches long, and expands 5½ it is greyish-black and bristly, the eyes are chestnut colour, naked, approximation on the crown, the inner margin silver)’ white; antennae drooping, five-jointed, third joint oblong, fourth a slender elongated basal joint to the longish pubescent seta; thorax with five indistinct stripes down the back, second and third abdominal segments with bright ochreous spots on each side, third rarely with two similar minute spots wings transparent, nervures dark, the two transverse ones not very remote balancers pale tawny legs black, base of shanks indistinctly ferruginous.

Female ashy slate colour, the eyes smaller than those of the male and remote; the face not silvery, thorax with five distinct broad blackish lines down the back, abdomen ovate-conic, with two indistinct ochreous slightly diaphanous spots on the second abdominal segments; in other respects this sex is similar to the male.

The larvae, although indolent, can crawl well; they are of a dull tawny, colour, clothed with long bristly spines, somewhat depressed, elliptical, tapering to the head, which is waved about, and when thrust out is whitish and fleshy, armed with two minute hooks like ebony, and there is a little fleshy horn on each side.

On the following segment is a spiracle on either side, surrounded by several stout short rays; the two next segments have tubercles on the back; the remainder have a double series down the center producing bristles, with a double row on each side, and eight of the segments have a pair of short spines on each beneath, which enable it to walk; the apex is armed with six long bristles a little spiny at the base, but most of the others are naked, or with the slightest appearance of pubescence or little spines at the base; on the apical segment are two spiracular tubes. The pupa being formed within the indurated skin of the larva, it varies from it only in being more convex above, and the fly escapes by a lateral opening in the thorax.

Drosophila Cellaris:

It is 1 ½ inches long, and expands 4 inches: the general colour is ochreous: the head is broad as well as the face, in the centre of which are inserted the two little drooping pubescent horns, the third joint is oval, and from the back arises a feathery bristle jointed at the base: orifice forming the mouth the very large; eyes large, hemispherical; ocelli three on the crown; thorax globose-quadrate; scutel semi-ovate, abdomen small, depressed, oval blackish, and six-jointed, with four or five ochreous bands; the apex pointed in the female; wings incumbent in repose, very long and ample, yellowish and iridescent, with a very short marginal cell, and four longitudinal nervures, the second and third united towards the base, the third and fourth towards the margin; balancers small, clavate, six legs tapering, feet long, slender, and five- jointed, terminated by minute claws.

The larvae are 2½ lines long, of a whitish colour, tapering towards the head, composed of twelve joints; on each side of the thoracic segment is a short branching spiracle, and the tail is furnished with four divaricating blunt spines, the edges of the segments being serrated with hooked ones. When full grown, this skin becomes horny changing to a rust colour the maggot is transformed to a pupa within an internal horny shell of a chestnut colour, and of course the pupa greatly resembles the larva.

There is also an extensive group of flies called Borborus, the larvae of which live upon decomposing vegetable and probably animal substances also: at all events they are generated in fungi. A portion of these flies is now distinguished by Macquart under the generic name of Limousine.

L. Geniculate:

It is only 1 inch long, and expands a little more than inches. It is black; the head is moderately large, with an ample cavity beneath to receive the mouth. The eyes are hemispheric and rust-coloured, and there are three minute ocelli on the crown; the face is concave, with two little horns in the centre, the third joint orbicular, with a tomentose seta, thorax broader, very convex; scutel semi orbicular and flat, abdomen very short, die segments equal in length, wings rather small, smoky, nervures pitchy; costal the strongest; sub-marginal cell not extending to the apex, second and third longitudinal nervures united at the middle, third and fourth forming a loop with two minute branches at the extremity; balancers small and ochreous, legs pitchy; hips ochreous, as well as the tips of the anterior thighs and the base of the shanks; hinder with a few spines outside; feet long, five-jointed, especially the hinder, which are slender and longer than the shanks; dull ochreous, basal joint very long and pitchy, terminal one very short, and furnished with short claws.

M. Rayer also observed a crecies in the infected potatoes which has been named by Guerin Limosina payenii, and it is not improbable that it may be the male of Macquart’s species, for it agrees very well with our female, except in the colour of the wings and the structure of the hinder feet.

D. Febrilis:

D. fehrilis is intensely black, shining, and hairy. The head of the male is hemispheric, and covered with large densely pubescent eyes of a reddish-brown colour; there are three minute ocelli forming an elevated triangle near the base the lip is broad, and the feelers incurved.

The trunk is oval and gibbose, with two transverse rows of minute teeth before: the scutel is short and broad abdomen sub linear, eight- jointed, the apex clubbed the two wings are incumbent in repose, perfectly transparent and white but iridescent the pinion only is slightly tinged with brown, the costal nervures pitchy, the others very faintly marked; a radial nervure uniting with the costa at the middle forms a brown spot at the extremity two balancers, with a large compressed brown club: it has six long legs; anterior thighs the thickest, the shanks very short, the apex surrounded by a coronet of teeth; there are also several short spines outside; feet slender, five-jointed, terminated by claws and suckers: length, 2½ inches; expanse, 5 inches.

The female is larger and very different, the head being much less, with small oval eyes not meeting on the crown the abdomen is brownish and elongated, ovate at the extremity but narrowed at the base, and the tip is furnished with two minute tubercles: the wings are much longer and very ample, entirely brown, the pinion being the darkest, with a brown stigmatic spot; all the nervures are pitchy; the anterior thighs are incrassated.

These insects fly heavily, their hinder legs banging down, and in the evening they become sluggish, resting on herbage and bushes. The larvae also inhabit cow-dung and horse muck: it is therefore very possible they may be introduced into potato-grounds with the manure, or the flies may be attracted to highly manured ground to deposit their eggs; for so little is known of the economy of many insects, that it is impossible to determine their exact habits: indeed no description or figures were to be found of the larvae and pupae of the fly.

9. False Scorpions:

These singular little creature have occurred in some numbers amongst decaying potatoes, where probably they live upon the mites, as one species is known to be very serviceable in keeping under those pests in cabinets of natural history; others are found attached to the legs of house-flies so firmly that it is scarcely possible to remove them, but whether they destroy the fly, or only avail themselves of their power of flight to be carried from one locality to another, is not known. These false scorpions belong to an Order called by Latreille Trachearle, to the Family Cheliferide, and the Genus Chelifer.

P. Brachialis:

The male is scarcely 1 inch long, and expands 1½ it is very glossy black; the head is globose; the face short, ovate, and at the bottom are attached the antennae, which are nearly as long as the body, ferruginous, and fourteen-jointed, basal joint long, second short, obovate, third notched or comma-shaped, remainder short and obovate, apical joint conical; eyes small, lateral, with three ocelli on the crown in a triangle, thorax very globose, scarcely larger than the head scutel small, semi- oval, deeply hollowed at the base; metathorax ferruginous and uneven; petiole forming a ferruginous knob wooly behind; abdomen small, ovate-conic, pitchy, base ferruginous, with four longitudinal channels on a very large segment, apical segment very short, four wings dusky and pubescent, with a few nervures at the base of the superior, forming an elongated cell six legs short, slender, and ochreous, pitchy at the base; thighs thickened, as well as the anterior shanks, and pitchy at the middle; feet slender, five-jointed, tips dusky.

Female above 1 inch long, and expanding 1¾ this sex is not only distinguished by its larger size, but the horns are shorter, with only twelve joints, the third being simple like the second; and the extremity of the abdomen is acuminated, and very acute.

This insect belongs to a family which is very serviceable in keeping down wireworms and other subterranean larvae, and the Gardeners’ chronicles. Nees also says that the Diaprioe breed in the subterranean larvae of Tipuloe, or Gnats.

C. Inoequalis:

It is ¾ of a line ling, of a lively rust colour, the head is pointed; the two little eyes are scarcely visible; the feelers are like the claws of a crab, as long as the body, smooth with scattered hairs, and four- jointed; the basal joint is short, hatchet-shaped, second twice as long and oblong, third as large, pear-shaped, fourth the larges, oval, terminated by two long slender claws, forming pincers; thorax oval, with a transverse suture across the middle: body oval, and brown with scattered hairs, furnished with eight shortish, ochreous, shining legs; four first the shortest, five-jointed, and terminated by minute double black claw.

10. Worms:

It may be remembered that in discussing the minute animals which affect the wheat crops, a very remarkable little worm called Vibrio tritici was described and figured, and its history was also detailed. It has discovered a similar species which breeds in multitudes in rotten potatoes.

This Vibrio is named by Guerin, Rhabditis tuberculorum, and is shorter and stouter in its young state: the tail of the male is rounded, conical and pointed in the female: the mouth is furnished with two rounded nipples, and a third between them connected with the oesophagus, and the body is devoid of articulations: it is not thicker than the finest hair, and scarcely visible in response.

Snails and slugs injure the potato crops, enlarging the holes perforated by wireworms, snake millipedes, and other subterranean animals, which is one good reason for lifting the crop as soon as the tubers are ripe, to prevent unnecessary waste.

A bag was found in a cooked potato, containing eleven white globular pellucid eggs, scarcely so large as mustard-seeds: they were a little pointed at one end, and had every appearance of having been laid in the cavity by a slug, which is exceedingly probable, where they had feasted so long and increased so greatly in bulk, that it was impossible to withdraw them without enlarging the orifice.

As the tap-rooted vegetables are likely to become of more importance in field culture, both as food for cattle and man, and acquaintance with the enemies which assail and injure the carrots and parsnips must not be neglected, for such knowledge is actually necessary to their successful cultivation. One of the best substitute for the potato not only as regards its nutritive qualities, but its products also; and when a taste for it is once acquired, it becomes a most agreeable culinary vegetable: it is also sufficiently solid to satisfy hunger, and it is gently aperient.

The greatest objection appears to be the length of time it occupies the ground, as parsnips keep best in the earth; but this inconvenience, as far as the cottager is concerned, might be remedied by lifting the roots when full grown, about Christmas, and pecking them vertically, close together, in some spare spot, from whence they could be drawn as they were wanted.

It is desirable to vary the vegetables which so largely contribute to the support of the labouring classes; or any other vegetable, eaten day after day, will not conduce to health and strength as the use of three or four different sorts will alternately: the culture, therefore, of broad and scarlet beans, Jerusalem artichokes, and parsnips, would make a wholesome, agreeable, and profitable variety in the poor man’s bill of fare, in combination with potatoes, greens turnips and onions. Carrots are already so valuable in some countries, that the failure of them is severely felt.

As soon as the tap-root is formed, until the period of its being matured the maggots of a fly, as well as other little animals, including slugs, are constantly diminishing the produce. The young foliage no sooner appears than it is filled with Aphides, and at a more advanced stages the leaves become an agreeable food for caterpillars; and lastly, the seed-crops are almost annihilated by smaller caterpillars, which devour the flowers as well as the seeds.

Aphis Dauci-The Carrot-Leaf Plant-Louse:

It has been observed in the field of carrots, having a strong plant; but one-tenth of the crop had recently gone off. This malady was indicated by the yellow foliage, and on pulling up the roots they were sound and clean; yet the crowns were not only dis-coloured, but dead or dying, and on opening the embryo leaves we found concealed at the base from two to seven or eight green Aphides-were gone, excepting a female, which had been punctured by some parasite; and it was evident they had commenced their operations earlier in the year, for the central leaves were hard and black. In this instance the tap roots were becoming woody inside, and some of them were throwing out quantities of fibrous roots, like old growing carrots which had been kept through the winter.

These Aphides were scarcely larger than cheese-mites of a uniform pale-green colour, with six legs, two horns, and no wings. Aphides, when infested were scattered over the leaves, and a great number of punctured ones were visible; from these were bred a parasitic Cynips and minute Trionys. The Aphides were small, principally green but some of them were dirty-yellowish, tinged with red; perhaps these were the receptacles of the parasites: eyes black; horns short, seven-jointed, blackish at the tips; rostrum not ling, stoutest, tipped with black: abdominal tubes rather long sub-fusiform, orifices black; tipped with black abdominal tubes rather long, sub-fusiform, orifices black; legs rather short, green; feet smoky; pupae light-green, clouded with grass- green.

As soon as a bed is affected by Aphides, powdered tobacco should be dusted over the crowns of the carrots early in the morning whilst the dew is upon them, or they may be watered with a decoction of tobacco, which is fatal to all plant-lice. Removing the dying plants is of little use, as the insects remove from them as soon as the foliage produces no more sap. Another species of Aphis is found in October on the roots, and being of an ochreous or pale yellow colour, it is not easily detected.