The footless larvae are elongate, worm-like and very active; they feed upon almost any kind of waste animal matter, and when full-grown form a silken cocoon.
The oak in Europe is liable to injury from a great variety of insect enemies: the young wood is attacked by the larvae of the small stag-beetle and several other Coleoptera, and those of the wood-leopard moth, goat moth and other Lepidoptera feed upon it occasionally; the foliage is devoured by innumerable larvae; indeed, it has been stated that half the plant-eating insects of England prey more or less upon the oak, and in some seasons it is difficult to find a leaf perfectly free from their depredations.
the ground and the young larvae make their way into grasshoppers, in whose bodies they pass most of their larval life.
Manson showed in 1881 that the larvae (Microfilariae) were not at all times present in the blood, but that their appearance had a certain periodicity, and the larvae of F.
Ten years later Manson discovered a second species, Filaria perstans, whose larvae live in the blood.
The presence of these parasites seems at times to have little effect on the host, and men in whose system it is calculated there are some 40-50 million larvae have shown no signs of disease.
Next the larvae make their way into the connective tissue in the pro-thorax, and ultimately bore a channel into the base of the piercing apparatus and come to rest between the hypopharynx and the labium.
From their position in the proboscis the larvae can easily enter the blood of man the next time the mosquito bites (Low, Brit.
Shortly after Low had published his results, Grassi and Noe issued a paper dealing with the larvae of F.
The larvae of this parasite develop in the Malpighian tubules of the insect; at a certain stage they cast their cuticle and make their way into the space - part of the haemocoel - found in the labium.
Besides Anopheles, two species of Culex, C. penicillaris and C. pipiens, are also accused of transmitting the larvae.
A paper by Noe (Atti Acc. Lincei, ix., 1900) seems to prove beyond doubt that the larvae of F.
The females produce thousands of larvae, which circulate in the blood, and show a certain periodicity in their appearance, being much more numerous in the blood at night than during the day.
Not to speak of insects which feed upon the pitcher itself, some drop their eggs into the putrescent mass, where their larvae find abundant nourishment, while birds often slit open the pitchers with their beaks and devour the maggots in their turn.
It is of nocturnal and burrowing habits, and feeds on decomposed animal substances, larvae and termites.
P. alba suffers much from the ravages of wood-eating larvae, and also from fungoid growths, especially where the branches have been removed by pruning or accident.
TADPOLE, a term often, but wrongly, applied indiscriminately to all Batrachian larvae.
In some species of Rana and Staurois inhabiting mountainous districts in south-eastern Asia, the larvae are adapted for life in torrents, being provided with a circular adhesive disk on the ventral surface behind the mouth, by means of which they are able to anchor themselves to stones.
Various local hypertrophies, including galls, result from the increased growth of young tissues irritated by the punctures of insects, or by the presence of eggs or larvae left behind.
18, 21 b); the body shortened, with the abdomen swollen, but protected with tubercles and spines, and with longish legs adapted for an active life, as in the predaceous larvae of ladybirds; the body soft-skinned, swollen and caterpillar-like, with legs well developed, but leading a sluggish underground life, as in the grub of a chafer; the body soft-skinned and whitish, and the legs greatly reduced in size, as in the wood-feeding grub of a longhorn beetle.
The distribution of many groups of beetles is restricted in correspondence with their habits; the Cerambycidae (longhorns), whose larvae are wood-borers, are absent from timberless regions, and most abundant in the great tropical forests.
Some of the scavengers, like the burying beetles, inter the bodies of small vertebrates to supply food for themselves and their larvae, or, like the "sacred" beetle of Egypt, collect for the same purpose stores of dung.
These stridulating organs were mentioned by C. Darwin as probable examples of the action of sexual selection; they are, however, frequently present in both sexes, and in some families also in the larvae.
The root-feeding larvae of the cockchafer and allied members of the Scarabaeidae have a ridged area on the mandible, which is scraped by teeth on the maxillae, apparently forming a stridulating organ.
The eggs and larvae of the fire-flies are luminous as well as the perfect beetles.
Macleay's classification (1825), which rested principally on the characters of the larvae, is almost forgotten nowadays, but it is certain that in any systematic arrangement which claims to be natural the early stages in the life-history must receive due attention.
Ganglbauer (1892) divides the whole order into two sub-orders only, the Caraboidea (the Adephaga of Sharp and the older writers) and the Cantharidoidea (including all other beetles), since the larvae of Caraboidea have five-segmented, two-clawed legs, while those of all other beetles have legs with four segments and a single claw.
Kolbe, on the other hand, insists that the weevils are the most modified of all beetles, being highly specialized as regards their adult structure, and developing from legless maggots exceedingly different from the adult; he regards the Adephaga, with their active armoured larvae with two foot-claws, as the most primitive group of beetles, and there can be little doubt that the likeness between larvae and adult may safely be accepted as a primitive character among insects.
Two very small families of aquatic beetles seem to stand at the base of the series, the Amphizoidae, whose larvae are broad and well armoured with FIG.
2 b) possess slender, curved, hollow mandibles, which are perforated at the tip and at the base, being thus adapted for sucking the juices of victims. Large dyticid larvae often attack small fishes and tadpoles.
mandibles being well adapted for the capture of small insect-victims. The larvae are more specialized than those of other Adephaga, the head and prothorax being very large and broad, the succeeding segments slender and incompletely chitinized.
I I) and Necrophaga are valuable scavengers from their habit of burying small vertebrate carcases which may serve as food for their larvae.
The Staph y linid larvae are typically campodeiform.
Beetles and larvae are frequently carnivorous in habit, hunting for small insects under stones, or pursuing the soft-skinned grubs of beetles and flies that bore in woody stems or succulent roots.
The beetles are hairy and their larvae well-armoured and often predaceous.
According to Sharp, all Dermestid larvae probably feed on dried animal matters; he mentions one species that can find sufficient food in the horsehair of furniture, and another that eats the dried insect-skins hanging in old cobwebs.
The larvae are elongate and worm-like, with short legs but often with hard strong cuticle.
The larvae of Elateridae are elongate, worm-like grubs, with narrow bodies, very firm cuticle, short legs, and a distinct anal proleg.
Several of the elaterid larvae, however, gnaw roots and are highly destructive to farm crops.
The larvae are remarkable for their small head, very broad thorax, with reduced legs, and narrow elongate abdomen.
The larvae are stout and soft-skinned, with short legs in correlation with their burrowing habit.
A large number of families, distinguished from each other by more or less trivial characters, are included here, and there is considerable diversity in the form of the larvae.
The larvae in this family are well-armoured, active and predaceous.
In the European species of Sitaris and Meloe these little larvae have the instinct of clinging to any hairy object.
While thus carried about by the host-insect, the female is fertilized by the free-flying male, and gives birth to a number of tiny triungulin larvae.
The larvae are furnished with large heads, powerful mandibles and well-developed legs, but the body-segments are feebly chitinized, and the tail-end is swollen.
The larvae of Lucanidae live within the wood of trees, and may take three or four years to attain their full growth.
The larvae have the three pairs of legs well developed, and the hinder abdominal segments swollen.
they reappear to bury another supply of dung, which serves as food for the larvae.
The larvae have soft-skinned bodies sometimes protected by rows of spiny tubercles, the legs being fairly developed in some families and greatly segments to the foot, but there are really five, the fourth being greatly reduced.
Such larvae, and also many with soft cuticle and swollen abdomen - those of the notorious "Colorado beetle," for example - feed openly FIG.
The larvae have a somewhat swollen abdomen, which is protected by bristle-bearing tubercles.
The larvae of the tortoise-beetles have the curious habit of forming an umbrella-like shield out of their own excrement, held in position by the upturned tail-process.
The larvae of the beautiful, elongate, metallic Donaciae live in the roots and stems of aquatic plants, obtaining thence both food and air.
The larvae have soft, fleshy bodies, with the head and prothorax large and broad, and the legs very much reduced.
The larvae have soft, white bodies and, with very few exceptions, no legs.
39) have jointed, flexible palps, feelers - often of excessive length - with a short basal segment, and the three terminal segments forming a club, and, in some genera, larvae with legs.
All puddles and collections of water should be filled in or drained; as a temporary expedient they may be treated with petroleum, which prevents the development of the larvae.
Ziemann advocates the destruction of mosquito larvae by the growing of such plants.
as the waterpest (Anacharis alsinatrum) which covers the surface of the water and suffocates larvae and nymphae.
Metamorphosis in Diptera is complete; the larvae are utterly different from the perfect insects in appearance, and, although varying greatly in outward form, are usually footless grubs; those of the Muscidae are generally known as maggots.
In these forms the pregnant female, instead of laying eggs, as Diptera usually do, or even producing a number of minute living larvae, gives birth at one time but to a single larva, which is retained within the oviduct of the mother until adult, and assumes the pupal state immediately on extrusion.
That Diptera of the type of the common house-fly are often in large measure responsible for the spread of such diseases as cholera and enteric fever is undeniable, and as regards blood-sucking forms, in addition to those to which reference has already been made, it is sufficient to mention the vast army of pests constituted by the midges, sand-flies, horseflies, &c., from the attacks of which domestic animals suffer equally with man, in addition to being frequently infested with the larvae of the bot and warble flies (Gastrophilus, Oestrus and Hypoderma).
Lastly, as regards the phytophagous forms, there can be no doubt that the destruction of grass-lands by "leatherjackets" (the larvae of crane-flies, or daddy-long-legs, - Tipula oleracea and T.
The foundress of the nest lays eggs and at first feeds and rears the larvae, the earliest of which develop into workers.
These workers then take on themselves the labour of the colony, some collecting food, which they transfer to their comrades within the nest whose duty is to tend and feed the larvae.
It is thought that the differences are, in part at least, due to differences in the nature of the food supplied to larvae, which are apparently all alike.
Some of the inmates of ants' nests are here for the purpose of preying upon the :ants or their larvae, so that we find all kinds of relations between the owners of the nests and their companions, from mutual benefit to active hostility.
The Solenopsis can make its way into the territory of the Formica to steal the larvae which serve it as food, but the Formica is too large to pursue the thief when it returns to its own galleries.
sanguinea can live either with or without slaves, but another European ant (Polyergus rufescens) is so dependent on its slaves - various species of Formica - that its workers are themselves unable to feed the larvae.
A number of larvae of Lepidoptera feed on the leaves - the remedy is to capture the mature insects when possible.
Larval " weevils " mostly feed on the roots of plants, but some, such as the nut weevil (Balaninus nucum), live as larvae inside fruit.
The larvae of these are usually spoken of as " false caterpillars," on account of their resemblance to the larvae of a moth.
Sawfly larvae can at once be recognized by the curious positions they assume, and by the number of pro-legs, which exceeds ten.
Currant and gooseberry are also attacked by sawfly larvae (Nematus ribesii and N.
Another group of Hymenoptera occasionally causes much harm in fir plantations, namely, the Siricidae or wood-wasps, whose larvae burrow into the trunks of the trees and thus kill them.
For all exposed sawfly larvae hellebore washes are most fatal, but they must not be used over ripe or ripening fruit, as the hellebore is poisonous.
Fruit suffers much from the larvae of the Geometridae, the socalled "looper-larvae" or " canker-worms."
In many years quite half the apple crop is lost in England owing to the larvae destroying the fruit.
Sugar-canes suffer from the sugar cane borer (Diatioca sacchari) in the West Indies; tobacco from the larvae of hawk moths (Sphingidae) in America; corn and grass from various Lepidopterous pests all over the world.
place in corn and flour from the presence of the larvae of the Mediterranean flour moth (Ephestia kuniella); while furs and clothes are often ruined by the clothes moth (Tinea trapezella).
The female lays her eggs beneath the scaly covering, from which hatch out little active six-legged larvae, which wander about and soon begin to form a new scale.
Enteroxenos, no pseudo pallium and no intestine, hermaphrodite, larvae with operculum.
Willughby, Ray and others in the late 17th century to include the active larvae of beetles, as well as bugs, lice, fleas and other insects with undeveloped wings.
Many insects have aquatic larvae, some of which take in atmospheric air at intervals, while others breathe dissolved air by means of tracheal gills.
The various larvae of the above series, however, have all a distinct head-capsule, which is altogether wanting in the degraded fly maggot.
But in general we find that elaboration of imaginal structure is associated with degradation in the nature of the larva, cruciform and vermiform larvae being characteristic of the highest orders of the Hexapoda, so that unlikeness between parent and offspring has increased with the evolution of the class.
The term nymph is applied by many writers on the Hexapoda to all young forms of insects that are not sufficiently unlike their parents to be called larvae.
The aquatic habit of many larvae is associated with endless beautiful adaptations for respiration.
The series of paired spiracles on most of the trunk-segments is well displayed, as a rule, in terrestrial larvae - caterpillars and the grubs of most beetles, for example.
25, d) is seen in many larvae of flies (Diptera) that live and feed buried in carrion or excrement.
Other aquatic larvae have the tracheal system entirely closed, and are able to breathe dissolved air by means of tubular or leaf-like gills.
Nevertheless, the function of reproduction is occasionally exercised by larvae.
The larvae produced by this remarkable method (paedogenesis) of virgin-reproduction are hatched within the parent larva, and in some cases escape by the rupture of its body.
Aquatic larvae with distinct maxillulae, breathing dissolved air by abdominal tracheal gills.
Aquatic larvae with caudal leaf-gills or with rectal tracheal system.
Young often larvae.
No locomotor abdominal appendages (except in certain larvae).
Larvae aquatic and cruciform.
Larvae eruciform, with rarely more than five pairs of abdominal prolegs.
Larvae eruciform without thoracic legs, or vermiform without head-capsule.
Larvae caterpillars with thoracic legs and abdominal prolegs.
Larvae legless grubs.
But a survey of the Hexapoda as a whole, and especially a comparative study of the tracheal system, can hardly leave room for doubt that this system is primitively adapted for atmospheric breathing, and that the presence of tracheal gills in larvae must be regarded as a special adaptation for temporary aquatic life.
As shown by the number and variety of species, the Orthoptera are the most dominant order of this group. Eminently terrestrial in habit, the differentiation of their fore-wings and hindwings can be traced from Carboniferous, isopteroid ancestors through intermediate Mesozoic forms. The Plecoptera resemble the Ephemeroptera and Odonata in the aquatic habits of their larvae, and by the occasional presence of tufted thoracic gills in the imago exhibit an aquatic character unknown in any other winged insects.
The Neuroptera, with their similar foreand hind-wings and their campodeiform larvae, seem to stand nearest to the presumed isopteroid ancestry, but the imago and larva are often specialized.
The campodeiform larvae of many Coleoptera are indeed far more primitive than the neuropteran larvae, and suggest to us that the Coleoptera - modified as their wing-structure has become - arose very early from the primitive metabolous stock.
The eruciform larva of the Orthorrhapha leads on to the headless vermiform maggot of the Cyclorrhapha, and in the latter sub-order we find metamorphosis carried to its extreme point, the muscid flies being the most highly specialized of all the Hexapoda as regards structure, while their maggots are the most degraded of all insect larvae.
As a commercial product spider-silk has been found to be equal, if not superior, to the best silk spun by lepidopterous larvae; but the cannibalistic propensities of spiders, making it impossible to keep more than one in a single receptacle, coupled with the difficulty of getting them to spin freely in a confined space, have hitherto prevented the silk being used on any extensive scale for textile fabrics.
Now, Coccinellidae (ladybirds) are known to be highly distasteful to most insectivorous mammals and birds, and snails would be quite unfit food for the Pompilid or Ichneumonid larvae, so that the reason for the mimicry in these cases is also perfectly clear.
The " cotton stainers," various species of Dysdercus, are widely distributed, occurring for example in America, the West Indies, Africa, India, &c. The larvae suck the sap from the young bolls and seeds, causing shrivelling and reduction in quantity of fibre.
- Tarsal joint of an Ephemerid larva into which two Gordius larvae, (a,a) have penetrated.
If they fall on pasture land or fodder of any kind and are eaten by any herbivorous animal, such as a hare, rabbit, horse, sheep or ox, the active embryos or larvae are set free in the alimentary canal of the new host.
These larvae are minute oval creatures with a comparatively short apically fringed caudal prolongation and furnished with two pairs of short two-clawed processes, which may represent the limbs of anthropods and possibly the two pairs of legs found in Acari of the family Eriophyidae.
In the event of the host escaping being killed and eaten it is believed that some of these larvae wander about or ultimately make their way to the exterior, possibly through the bronchi; nevertheless it seems to be certain that they can only reach sexual maturity in the nasal passages of some carnivorous animal, and the chance of attaining this environment is afforded when the viscera of the host are devoured by some flesh-eating mammal.
The size of the animals varies greatly, from forms a few millimetres in length to Gigantorhynchus gigas, which measures from 10 to 65 cms. The adults live in great numbers in the alimentary canal of some vertebrate, usually fish, the larvae are as a rule encysted in the body cavity of some invertebrate, most often an insect or crustacean, more rarely a small fish.
moniliformis has for its larval host the larvae of the beetle Blaps mucronata, for its final host certain mice, if introduced into man it lives well: E.
This animal spends most of its time burrowing in the sand in search of insects and their larvae, but occasionally makes its appearance on the surface.
Spiders, caterpillars and grasshoppers are, he said, stung in their chief nerve-centres, in consequence of which the victims are not killed outright, but rendered motionless and continue to live in this paralysed condition for several weeks, being thus available as food for the larvae when these are hatched.
But the Peckhams' careful observations and experiments show that, with the American wasps, the victims stored in the nests are quite as often dead as alive; that those which are only paralysed live for a varying number of days, some more, some less; that wasp larvae thrive just as well on dead victims, sometimes dried up, sometimes undergoing decomposition, as on living and paralysed prey; that the nerve-centres are not stung with the supposed uniformity; and that in some cases paralysis, in others death, follows when the victims are stung in parts far removed from any nerve-centre.
Probably several months elapse before the young larvae are excluded.
Joly, the very young larvae have no breathing organs, and respiration is effected through the skin.
There may be said to be three or four different modes of life in these larvae: some are fossorial, and form tubes in the mud or clay in which they live; others are found on or beneath stones; while others again swim and crawl freely among water plants.
It is probable that some are carnivorous, either attacking other larvae or subsisting on more minute forms of animal life; but others perhaps feed more exclusively on vegetable matters of a low type, such as diatoms.
The Tornaria larva offers a certain similarity to larvae of Echinoderms (sea-urchins, star-fishes, and sea-cucumbers), and when first discovered was so described.
About this stage the larvae leave the broodpouch, which is a lateral or median cavity in the body of the female, and lead a free swimming life in the ocean.
These larvae, which resemble those described by Fritz Muller (Arch.
xliv.) has classified with appropriate names the various stages through which Brachiopod larvae pass.
- Three larvae stages of Megathyris (Argiope).
I t may, however, be pointed out that Brachiopods seem to belong to that class of animal which commences life as a larva with three segments, and that tri-segmented larvae have been found now in several of the larger groups.
Such cases are the habits of " shamming dead " and the combined posturing and colour peculiarities of certain caterpillars (Lepidopterous larvae) which cause them to resemble dead twigs or similar surrounding objects.
i, also " Artificial Production of Normal Larvae," Amer.
The Elasmobranchs swallow infected molluscs or fish; pike and trout devour smaller fry; birds pick up sticklebacks, insects and worms which contain Cestode larvae; and man lays himself open to infection by eating the uncooked or partially prepared flesh of many animals.
The evolution of the cysticercoid, cysticercus and other forms of larvae is a varied adaptive phenomenon.
murina, in the rat and mouse, the adult in the lumen of the intestine, the larvae in the villi.
To destroy the seeds, &c., of weeds, and the larvae of insect pests, a fire is often lighted, kept from the ground itself by intervening wood logs, or the seed-bed is thoroughly steamed.
The " tobacco flea-beetle " (Epitrix parvula, Fabr.) is a small active beetle, the larvae of which attack the roots, while the adult beetles eat holes in the leaves.
The latter is the more serious, as in addition to the actual damage done by the beetle the holes afford entrance to fungus spores, &c. Under the name " horn worms " are included the larvae or caterpillars of species of Protoparce.
The blackbird feeds chiefly on fruits, worms, the larvae of insects and snails, extracting the last from their shells by dexterously chipping them on stones; and though it is generally regarded as an enemy of the garden, it is probable that the amount of damage by it to the fruit is largely compensated for by its undoubted services as a vermin-killer.
The Euculicidae are divided into the Asiphonatae (=Anophelinae), the larvae of which have no respiratory siphon, and the Siphonatae, or forms in which a respiratory siphon is present in the larval state.
The nature of the breeding-place varies greatly according to the species, and while many of the mosquitoes that infest houses will breed even in the smallest accidental accumulation of water such as may have collected in a discarded bottle or tin, the larvae of other species less closely associated with man are found in natural pools or ditches, at the margins of slow-moving streams, in collections of water in hollow trees and bamboo-stumps, or even in the water-receptacles of certain plants.
The larvae are active and voracious little grub-like creatures (known in the United States as "wrigglers"), with large heads and jaws provided with a pair of brushes, which sweep food-particles into the mouth.
The larvae of species belonging to the Culicinae have a prominent breathing tube, or respiratory siphon, on the penultimate (eighth) abdominal segment, and when taking in air hang head downwards (often nearly vertically) from the surface film.
Larvae of Anophelinae, on the other hand - which are grey, green or brown in colour, and often extremely difficult to see - have no respiratory siphon and lie almost !
The larvae are perfectly white at first and wingless, although in other respects not unlike their parents, but they are not mature insects until after the sixth casting of the skin.
Perhaps the most remarkable of these effects is that produced by the larvae of Gasterostomum.
A different but still more interesting result is produced by these Trematode larvae on certain lamellibranchs.
5) is remarkable in that two larvae (the so-called Diporpae) unite and fuse permanently into an X-shaped organism.
Unless this occurs, the development of the larvae is soon arrested.
The larvae usually live in Molluscs, the mature worm in vertebrates, and the immature but metamorphosed Trematode in either host and also in pelagic and littoral marine and fresh-water invertebrates.
These cells aggregated in masses become the bodies of another generation of larvae within the sporocyst.
By a series of changes similar to those by which the primary larva arose from a segmented egg, so do these secondary larvae or "rediae" arise from the germ-cells or germ-balls within the sporocyst.
In the course of a few months it attains full size and maturity and probably in most cases dies in the course of a year after having given rise to another generation of larvae.
In many cases it appears that only the brilliantly coloured tentacle is pecked off by the bird, and as the snail can easily regenerate a new one, this in turn becomes infected by a fresh branch of the sporocyst ramifying through the snail and thus a new supply of larvae is speedily provided (Heckert).
The life-history of Schistostomum haematobium is still unknown, but the difficulty in obtaining developmental stages in any of the numerous intermediate hosts that have been tried suggests that the ciliated larvae may develop directly in man and either gain access to him by the use of impure water for drinking or may perforate his skin when bathing.
These are probably important in checking overgrowth by encrusting organisms, and in particular by preventing larvae from fixing on the zoarium.
It is terminated by a well-developed structure (fg) corresponding with the apical sense-organ of ordinary Trochospheres, and an excretory organ (nph) of the type familiar in these larvae occurs on the ventral side of the stomach.
The practical importance of this peculiar life-history is very great, since larvae thus protected cannot easily be destroyed.
The larvae known as caddis-worms are aquatic. The mature females lay their eggs in the water, and the newly-hatched larvae provide themselves with cases made of various particles such as grains of sand, pieces of wood or leaves stuck together with silk secreted from the salivary glands of the insect.
The larvae of several nocturnal Lepidoptera feed upon the leaves of the willows, and the trunk of the sallow is often injured by the perforations of the lunar hornet sphinx (Trochilium crabroniforme).
The development of a true insect society among the Hymenoptera is dependent on a differentiation among the females between individuals with well-developed ovaries (" queens ") whose special function is reproduction; and individuals with reduced or aborted ovaries (" workers ") whose duty is to build the nest, to gather food and to tend and feed the larvae.
Thus, wasps catch flies; worker ants make raids and carry off weak insects of many kinds; bees gather nectar from flowers and transform it into honey within their stomachs - largely for the sake of feeding the larvae in the nest.
On the other hand, there are thousands of very small species, and the tiny " fairy-flies " (Myynaridae), whose larvae live as parasites in the eggs of various insects, are excessivel y minute for creatures of such complex organization.
Comparatively only a few species are, for part of their lives, denizens of fresh water; these, as larvae, are parasitic on the eggs or larvae of other aquatic insects, the little hymenopteron, Polynema natans, one of the " fairy-flies " - swims through the water by strokes of her delicate wings in search of a dragon-fly's egg in which to lay her own egg, while the rare Agriotypus dives after the case of a caddis-worm.
No group of terrestrial insects escapes their attacks - even larvae boring in wood are detected by ichneumon flies with excessively long ovipositors.
This sub-order, characterized by the " sessile," broad-based abdomen, whose fist segment is imperfectly united with the thorax, and by the usually caterpillar-like larvae with legs, includes the various groups of saw-flies.
The soft, white larvae have the thoracic legs very small and feed in the stems of various plants.
The ovipositor is long and prominent, enabling the female insect to lay her eggs in the wood of trees, where the white larvae, whose legs are excessively short, tunnel and feed.
The Tenthredinidae, or true saw-flies, are distinguished by two spines on each fore-shin, while the larvae are usually caterpillars, with three pairs of thoracic legs, and from six to eight pairs of abdominal prolegs, the latter not possessing the hooks found on the pro-legs of lepidopterous caterpillars.
Most saw-fly larvae devour leaves, and the beautifully serrate processes of the ovipositor are well adapted for egg-laying in plant tissues.
- a, Pear Saw-fly (Eriocampoides limacina); b, larva without, and c, with its slimy protective coat; e, cocoon; f, larva before pupation; g, pupa, magnified 4 times; d, leaves with larvae, natural size.
Other flies of this group have the inquiline habit, laying their eggs in the galls of other species, while others again pierce the cuticle of maggots or aphids, in whose bodies their larvae live as parasites.
The vast majority of this group, including nearly 5000 known species, are usually reckoned as a single family, the Chalcididae, comprising small insects, often of bright metallic colours, whose larvae are parasitic in insects of various orders.
They are among the most minute of all insects and their larvae are probably all parasitic in insects' eggs.
8) in the bodies of insects and their larvae belonging to various orders.
The Trigonalidae, a small family whose larvae are parasitic in wasps' nests, also probably belong here.
In two of the families - the Mutillidae and Thynnidae - the females are wingless and the larvae live as parasites in the larvae of other insects; the female Mutilla enters humble-bees' nests and lays her eggs in the bee-grubs.
They make burrows wherein they place insects or spiders which they have caught and stung, laying their eggs beside the victim so that the young larvae find themselves in presence of an abundant and appropriate food-supply.
After the lapse of six, eight or twelve days, according to the temperature, the larvae hatch out of the eggs.
He carefully studied also the history of the ant and was the first to show that what had been commonly reputed to be "ants' eggs" are really their pupae, containing the perfect insect nearly ready for emersion, whilst the true eggs are far smaller, and give origin to "maggots" or larvae.
The larvae of the ribbon-footed corn-fly (Chlorops taeniopus) caused great injury to the barley crop in Great Britain in 1893, when the plant was weakened by extreme drought.
The larvae of the latter usually vacate their galls, to spin their cocoons in the earth, or, as in the case of Athalia abdominalis, Klg., of the clematis, may emerge from their shelter to feed for some days on the leaves of the gall-bearing plant.
Thus the galls of Cynips and its allies are inhabited by members of other cynipideous genera, as Synergus, Amblynotus and Synophrus; and the pine-cone-like gall of Salix strobiloides, as Walsh has shown, 2 is made by a large species of Cecidomyia, which inhabits the heart of the mass, the numerous smaller cecidomyidous larvae in its outer part being mere inquilines.
Callimome regius, the larva of which preys on the larvae of both Cynips glutinosa and its lodger Synergus facialis.
The oak-apple often contains the larvae of Braconidae and Ichneumonidae, which Von Schlechtendal (loc. sup. cit.
maculosa, which lives in plains or at low altitudes (up to 3000 ft.), deposits her young, ten to fifty in number, in the water, in springs or cool rivulets, and these young at birth are of small size, provided with external gills and four limbs, in every way similar to advanced newt larvae.
Embryos in the second stage, if artificially released from the uterus, are able to live in water, in the same way as similarly developed larvae of S.
Ambrosia beetles bore deep though minute galleries into trees and timber, and the wood-dust provides a bed for the growth of the fungus, on which the insects and larvae feed.
The youngest larvae are typical nauplii.
apparent that the larvae &c.," by permission of Macmillan & Co.
Its adhesive foot is paralleled by a cup-shaped ciliated depression, possibly nervous, found in all the larvae cited, except some Echinoderms, and which in Asterids and Crinoids actually serves as an organ of attachment.
We may note that it was long since shown that the apical organ (at first assumed to be the brain) of these larvae was innervated from an anterior thickening of the circular nerve ring, corresponding with the brain of Rotifers; the nerve cells immediately below the pit are the ordinary bipolar From H.
Males and larvae with a ciliated pedal cup and a simple ciliated disk.
In spring the chaffinch is destructive to early flowers, and to young radishes and turnips just as they appear above the surface; in summer, however, it feeds principally on insects and their larvae, while in autumn and winter its food consists of grain and other seeds.
At the anterior end of the test is the apical plate from the centre of which projects a long flagellum as in many other Lamellibranch larvae.
The other groups of the old Linnean order (such as lacewing-flies and caddis-flies)--which are hatched as larvae markedly unlike the parent, develop wing-rudiments hidden under the larval cuticle, and only show the wings externally in a resting pupal stage, passing thus through a " complete " metamorphosis and falling into the sub-class Endopterygotawere retained in the order Neuroptera, which thus became much restricted in its extent.
The larvae are active and well-armoured, upon the whole of the ' ` campodeiform " type, but destitute of cerci; they are predaceous in habit, usually with slender, sickle-shaped mandibles, wherewith they pierce various insects so as to suck their juices.
Fossil Neuroptera occur in the Lias and even in the Trias if the relationships of certain larvae have been correctly surmised.
Their predaceous, suctorial larvae are the well-known ant-lions (q.v.).
The lacewing-flies (q.v.), however, of which there are two families, the Hemerobiidae and Chrysopidae, whose larvae feed on Aphids, sucking their juices, are represented in our fauna.
Their larvae resemble those of the lacewings, attacking scale-insects and sucking their juices.
The family Phryganeidae have males with foursegmented hairy palps; the larvae inhabit stagnant water and make cases of vegetable fragments.
In the Limnephilidae the maxillary palp is three-segmented in the male, the larvae are variable in habit, many forming cases of snail-shells.
The males of the Sericostomatidae have two or three segmented palps; their larvae inhabit running water and make cases of grains of sand, or of small stones.
The stone-built cases of the carnivorous Hydropsychid larvae are familiar objects in the water of swift streams.
In the larvae of several Gastropoda and Lamellibranchia occur excretory organs which have the characters of true nephridia.
Advantage is taken of this peculiarity to prepare from fully developed larvae silkworm gut used for casting lines in rodfishing, and for numerous other purposes where lightness, tenacity, flexibility and strength are essential.
The larvae are killed and hardened by steeping some hours in strong acetic acid; the silk glands are then separated from the bodies, and the vis cous fluid drawn out to the condition of a fine uniform line, which is stretched between pins at the extremity of a board.
The eggs of the silkworm, called graine, are hatched out by artificial heat at the period when the mulberry leaves are ready for the feeding of the larvae.
Its eggs were first sent to Europe by Duchene du Bellecourt, French consulgeneral in Japan in 1861; but early in March following they hatched out, when no leaves on which the larvae would feed were to be found.
A few bananas and (especially from Oahu) pineapples of fine quality are exported; since 1901 the canning of 3 The entomological department of the Hawaii Experiment Station undertakes " mosquito control," and in 1905-1906 imported top-minnows (Poeciliidae) to destroy mosquito larvae.
Sometimes Lepidoptera mimic protected members of other orders of insects - such as Coleoptera, Hymenoptera and Hemiptera; but perhaps the most singular illustrations of the phenomenon known in the order are exemplified by the larvae of the hawk-moth Chaerocampa, which imitate the heads of snakes.
Professor Poulton long ago suggested, and supported the suggestion by experimental evidence on a lizard, that the larvae of two British species, C. elpenor and C. porcellus, are protected by the resemblance to the heads of snakes presented by the anterior extremities of their bodies which are ornamented with large eye-like spots.
When the larvae are disturbed the similarity is produced with startling suddenness by the telescopic contraction of the anterior segments in such a manner as to suggest a triangular, pointed head with two large dorsal eyes.
Another instance of mimicry affecting the larval form is supplied by the moth Endromis versicolor, the caterpillars of which resemble the inedible larvae of saw-flies.
The branches are some times attacked by weevils (Rhyn- cites) and the larvae of various moths, and saw-flies (chiefly Erio- campa) feed on the leaves, and young branches and leaves are sometimes invaded by Aphides.
Leaf-feeding beetles and larvae of moths are best got rid of by shaking the branches and collecting the insects.
Slug-worms or saw-fly larvae require treatment by washing with soapsuds, tobacco and lime-water or hellebore solution, and Aphides by syringing from below and removing all surplus young twigs.
Furs kept in such a condition are not only immune from the ravages of the larvae of moth, but all the natural oils in the pelt and fur are conserved, so that its colour and life are prolonged, and the natural deterioration is arrested.
It is said also to dig up the nests of wasps in order to eat the larvae, as the ratel - a closely allied South African form - is said to rob the bees of their honey.
When the time for eclosion has come, the male enters the water with his burden; the larvae, in the full tadpole condition, measuring 14 to 17 millimetres, bite their way through their tough envelope, which is not abandoned by the father until all the young are liberated, and complete in the ordinary way their metamorphosis.
The larvae are aquatic, active, armed with strong sharp mandibles, and breathe by means of seven pairs of abdominal branchial filaments.
AXOLOTL, the Mexican name given to larvae salamanders of the genus Amblystoma.
But for its large size - it grows to a length of eleven inches - it is a nearly exact image of the British newt larvae.
Dumeril, they and their offspring gave birth to 0000 or io,000 larvae during that period.
Lake Xochimilco contains powerful springs, but away from them the water appears dark and muddy, full of suspended fresh and decomposing vegetable matter, teeming with fish, larvae of insects, Daphniae, worms and axolotl.
The native fishermen know all about them; how the eggs are fastened to the water plants, how soon after the little larvae swarm about in thousands, how fast they grow, until by the month of June they are all grown into big, fat creatures ready for the market; later in the summer the axolotls are said to take to the rushes, in the autumn they become scarce, but none have ever been known to leave the water or to metamorphose, nor are any perfect Amblystomas found in the vicinity of the two lakes."
The same applies occasionally to European larvae, as in the case observed in the Italian Alps by F.
These floral products which form the food of bees and of their larvae, are in most cases collected and stored by the industrious insects; but some genera of bees act as inquilines or "cuckoo-parasites," laying their eggs in the nests of other bees, so that their larvae may feed at the expense of the rightful owners of the nest.
As is usual where an abundant food supply is provided for the young insects, the larvae of bees (fig.
But when Fabre substituted dead individuals of her own species or live larvae of another genus, the Osmia had no scruple in destroying them, so as to bite her way out to air and liberty.
Hence the two eggs are at opposite ends of the food, and both larvae feed for a time without conflict, but the Stelis, being the older, is the larger of the two.
For the fulfilment of this last condition, the older insects of the new generation must emerge from the cells while the mother is still occupied with the younger eggs or larvae.
In the nests of Bombi are found various beetle larvae that live as inquilines or parasites, and also maggots of drone-flies (V olucella), which act as scavengers; the Volucella-fly is usually a" mimic ' vades.
Dickel and others have lately claimed that fertilized eggs can give rise to either queens, workers or males, according to the food supplied to the larvae and the influence of supposed "sex-producing glands" possessed by the nurse-workers.
The leaves of the hazel are frequently found mined on the upper and under side respectively by the larvae of the moths Lithocolletis coryli and L.
- Anterior region of two pelagic larvae of A.
The larvae swim normally like the adult or suspend themselves by their flagella (not shown in the figures) vertically in mid-water.
The general subject has been illuminated by the labours of Claus, Miers, Brooks ("Challenger" Report, 1886), and the latest word on the relationship between the various larvae and their respective genera has been spoken by H.
P. sylvestris in Britain is liable to many insect depredations: the pine-chafer, Hylurgus piniperda, is destructive in some places, the larva of this beetle feeding on the young succulent shoots, especially in young plantations; Hylobius abietis, the fir-weevil, eats away the bark, and numerous lepidopterous larvae devour the leaves; the pine-sawfly is also injurious in some seasons; the removal of all dead branches from the trees and from the ground beneath them is recommended, as most of these insects lay their eggs among the decaying bark and dead leaves.
The larvae are extremely minute, about ff in.
From the trochosphere stage the free larvae pass into that of "veligers."
But if it is possible to procure a supply of spat from the American oyster by keeping the swarms of larvae in confinement, it ought to be possible in the case of the European oyster.
All that would be necessary would be to take a number of mature oysters containing white spat and lay them down in tanks till the larvae escape.
This would be merely carrying oyster culture a step farther back, and instead of collecting the newly fixed oysters, to obtain the free larvae in numbers and so insure a fall of spat independently of the uncertainty of natural conditions.
The wandering life of the larvae makes it uncerain whether any of the progeny of a given oyster-bed will settle within its area and so keep up its numbers.
It is known from the history of the Liimfjord beds that the larvae may settle 5 m.
The hatching of eggs, whether of fresh-water or salt-water fishes, presents no serious difficulties, if suitable apparatus is employed; but the rearing of fry to an advanced stage, without serious losses, is less easy, and in the case of sea-fishes with pelagic eggs, the larvae of which are exceedingly small and tender, is still an unsolved problem, although recent work, carried out at the Plymouth laboratory of the Marine Biological Association, is at least promising.
It has been found possible to grow pure cultures of various diatoms, and by feeding these to delicate larvae kept in sterilized sea-water, great successes have been attained.
If it is a risky matter to plant out the robust young fry of trout under an age of three months, it would seem to be an infinitely more speculative proceeding to plant out the delicate week-old larvae of sea-fishes in an environment which teems with predaceous enemies.
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