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单词 larva
释义

larva


lar·va

L0054300 (lär′və)n. pl. lar·vae (-vē) or lar·vas 1. a. The newly hatched, wingless, often wormlike form of many insects, developing into a pupa in species that undergo complete metamorphosis.b. The six-legged immature form of a tick or mite.2. The newly hatched, earliest form of any of various animals that undergo metamorphosis, differing markedly in appearance from the adult.3. Roman Mythology A malevolent spirit of the dead.
[Latin lārva, specter, mask (because it acts as a specter of or a mask for the adult form).]
lar′val adj.Word History: The word larva referring to the newly hatched form of insects before they undergo metamorphosis comes from the Latin word lārva, meaning "evil spirit, ghost, demon." The Latin word also was used to mean "a terrifying mask," such as one that might have been worn by a Roman performer in the role of such an evil spirit. In the 1600s and 1700s, scientists began to use the Latin word to describe the stage in an insect's life during which its final form is still hidden—the larval stage is a mask, so to speak, that the insect will later remove to reveal its adult appearance.

larva

(ˈlɑːvə) n, pl -vae (-viː) (Zoology) an immature free-living form of many animals that develops into a different adult form by metamorphosis[C18: (C17 in the original Latin sense: ghost): New Latin] ˈlarval adj

lar•va

(ˈlɑr və)

n., pl. -vae (-vi) 1. the immature, wingless, feeding stage of an insect that undergoes complete metamorphosis. 2. any animal in an analogous immature form. 3. the young of any invertebrate animal. [1645–55; < New Latin; Latin larva ghost, mask (akin to Lar); compare imago] lar′val, adj.

lar·va

(lär′və) Plural larvae (lär′vē) or larvas 1. An animal in an early stage of development that differs greatly in appearance from its adult stage. Larvae are adapted to a different environment and way of life than adults and go through a process of metamorphosis in changing to adults. Tadpoles are the larvae of frogs and toads.2. The immature, wingless, and usually worm-like feeding form of those insects that undergo three stages of metamorphosis, such as butterflies, moths, and beetles. Insect larvae hatch from eggs, later turn into pupae, and finally turn into adults. Compare imago, nymph, pupa.
Thesaurus
Noun1.larva - the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphoselarva - the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphoseanimal, animate being, beast, creature, fauna, brute - a living organism characterized by voluntary movementascidian tadpole - free-swimming larva of ascidians; they have a tail like a tadpole that contains the notochordbladder worm - encysted saclike larva of the tapewormcercaria - tadpole-shaped parasitic larva of a trematode worm; tail disappears in adult stagewireworm - wormlike larva of various elaterid beetles; feeds on roots of many crop plantsmealworm - the larva of beetles of the family Tenebrionidaewiggler, wriggler - larva of a mosquitojointworm, strawworm - larva of chalcid flies injurious to the straw of wheat and other grainsant lion, antlion, doodlebug - the larva of any of several insectsaphid lion, aphis lion - carnivorous larva of lacewing fliesdobson, hellgrammiate - large brown aquatic larva of the dobsonfly; used as fishing baitcaseworm - insect larva that constructs a protective case around its bodycaterpillar - a wormlike and often brightly colored and hairy or spiny larva of a butterfly or mothnymph - a larva of an insect with incomplete metamorphosis (as the dragonfly or mayfly)leptocephalus - slender transparent larva of eels and certain fishesbot - botfly larva; typically develops inside the body of a horse or sheep or humangrub - a soft thick wormlike larva of certain beetles and other insectspolliwog, pollywog, tadpole - a larval frog or toad
Translations
幼虫

larva

(ˈlaːvə) plural ˈlarvae (-viː) noun a developing insect in its first stage after coming out of the egg; a grub or caterpillar. 幼蟲 幼虫ˈlarval adjective 幼蟲的 幼虫的

larva


larva,

independent, immature animal that undergoes a profound change, or metamorphosis, to assume the typical adult form. Larvae occur in almost all of the animal phyla; because most are tiny or microscopic, they are rarely seen. They play diverse roles in the lives of animals. Motile larvae help to disseminate sessile, or sedentary, animals such as spongessponge,
common name for members of the aquatic animal phylum Porifera, and for the dried, processed skeletons of certain species used to hold water. Over 4,500 living species are known; they are found throughout the world, especially in shallow temperate waters.
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, oystersoyster,
bivalve mollusk found in beds in shallow, warm waters of all oceans. The shell is made up of two valves, the upper one flat and the lower convex, with variable outlines and a rough outer surface.
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, barnaclesbarnacle,
common name of the sedentary crustacean animals constituting the infraclass Cirripedia. Barnacles are exclusively marine and are quite unlike any other crustacean because of the permanently attached, or sessile, mode of existence for which they are highly modified.
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, or scale insects. Larvae of parasites may be dispersed by penetrating the skin of new hosts; other parasite larvae live in intermediate hosts that are normally eaten by the final host, in which the adult parasites develop. The larvae of other parasites live in and are dispersed by intermediate hosts such as mosquitoesmosquito
, small, long-legged insect of the order Diptera, the true flies. The females of most species have piercing and sucking mouth parts and apparently they must feed at least once upon mammalian blood before their eggs can develop properly.
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, gnatsgnat,
common name for any one of a number of small, fragile-looking two-winged flies of the suborder Nematocera, order Diptera, which includes the families Tipulidae (crane flies), Bibionidae (hairflies), Ceratopogonidae (biting midges), Chironomidae (true midges), Cecidomyidae
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, or leechesleech,
predacious or parasitic annelid worm of the class Hirudinea, characterized by a cylindrical or slightly flattened body with suckers at either end for attaching to prey.
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; when the blood meals are taken from the final host, the parasite larvae are introduced into the blood or skin. Parasitic infections can often be reduced by eliminating the larval hosts.

Vertebrate Larvae

Among vertebratesvertebrate,
any animal having a backbone or spinal column. Verbrates can be traced back to the Silurian period. In the adults of nearly all forms the backbone consists of a series of vertebrae. All vertebrates belong to the subphylum Vertebrata of the phylum Chordata.
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 a number of fishesfish,
limbless aquatic vertebrate animal with fins and internal gills. Traditionally the living fish have been divided into three class: the primitive jawless fishes, or Agnatha; the cartilaginous (sharklike) fishes, or Chondrichthyes; and the bony fishes, or Osteichthyes.
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 pass through larval stages; the larva of the eeleel,
common name for any fish in the order Anguilliformes, and characterized by a long snakelike body covered with minute scales embedded in the skin. Eels lack the hind pair of fins, adapting them for wriggling in the mud and through the crevices of reefs and rocky shores.
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 is interesting because it is flat and transparent. The tadpole, the familiar larva of the amphibianamphibian,
in zoology, cold-blooded vertebrate animal of the class Amphibia. There are three living orders of amphibians: the frogs and toads (order Anura, or Salientia), the salamanders and newts (order Urodela, or Caudata), and the caecilians, or limbless amphibians (order
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, develops to a considerable size in the relatively hospitable aquatic environment before metamorphosis prepares it for an amphibious or terrestrial life as a frogfrog,
common name for an amphibian of the order Anura. Frogs are found all over the world, except in Antarctica. They require moisture and usually live in quiet freshwater or in the woods. Some frogs are highly aquatic, while others are better adapted to terrestrial habitats.
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 or toadtoad,
name applied to certain members of the amphibian order Anura, which also includes the frog. Although there is no clear-cut distinction between toads and frogs, the name toad
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.

Insect Larvae

In some animals, especially insectsinsect,
invertebrate animal of the class Insecta of the phylum Arthropoda. Like other arthropods, an insect has a hard outer covering, or exoskeleton, a segmented body, and jointed legs. Adult insects typically have wings and are the only flying invertebrates.
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, larvae represent a special feeding stage in the life cycle. Some insects pass through more or less wormlike larval stages, enter the outwardly inactive, or pupal, form, and emerge from the pupal case as adults (see pupapupa
, name for the third stage in the life of an insect that undergoes complete metamorphosis, i.e., develops from the egg through the larva and the pupa stages to the adult.
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). The importance of larvae in the life cycle of insects varies greatly, as does the proportion of the life span spent in larval, pupal, and adult stages. In many insects, the adult life is relatively short, consisting mostly of mating and egg laying, while the larvae live for many months or, in some species, for several years. Insect larvae feed voraciously, necessarily becoming larger than the adult, as considerable energy and material are needed for the profound changes made during pupation. For this reason, insect larvae often cause far more damage to stored crops and textiles than adult insects.

Insect larvae generally have a thinner exoskeleton than the adult; many are white and soft. The characteristic flyfly,
name commonly used for any of a variety of winged insects, but properly restricted to members of the order Diptera, the true flies, which includes the housefly, gnat, midge, mosquito, and tsetse fly.
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 larvae are maggots, often developing in decaying plant or animal material. Mosquito larvae are the familiar aquatic wrigglers; they breathe air and are killed by a thin film of oil on the water that prevents contact with air. Maggots and wrigglers are legless, as are all larvae of the insect order Diptera. Beetlebeetle,
common name for insects of the order Coleoptera, which, with more than 300,000 described species, is the largest of the insect orders. Beetles have chewing mouthparts and well-developed antennae.
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 larvae, including the whitish forms called grubs and the long brownish wirewormswireworm,
elongate, cylindrical larva of the click beetle. Most wireworms are hard and brown, but members of some species are soft and whitish. Wireworms live in rotten wood or in the ground and feed on roots and seeds, injuring potatoes, grasses, and a wide variety of
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, are quite diverse, but all are equipped with the six legs characteristic of adults. Mothsmoth,
any of the large and varied group of insects which, along with the butterflies, make up the order Lepidoptera. The moths comprise the great majority of the 100,000 species of the order, and about 70 of its 80 families.
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 and butterfliesbutterfly,
any of a large group of insects found throughout most of the world; with the moths, they comprise the order Lepidoptera. There are about 12 families of butterflies. Most adult moths and butterflies feed on nectar sucked from flowers.
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 have wormlike caterpillars as larvae, each equipped with the six legs characteristic of adults and false legs known as prolegs to support the long abdominal section. Some, like the milkweed worm (the larva of the monarch butterfly), are relatively naked, while other caterpillars are covered by hairy bristles, sometimes equipped with irritating chemicals that can cause intense itching. The young of the social insects (beesbee,
name for flying insects of the superfamily Apoidea, in the same order as the ants and the wasps. Bees are characterized by their enlarged hind feet, typically equipped with pollen baskets of stiff hairs for gathering pollen.
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, antsant,
any of the 2,500 insect species constituting the family Formicidae of the order Hymenoptera, to which the bee and the wasp also belong. Like most members of the order, ants have a "wasp waist," that is, the front part of the abdomen forms a narrow stalk, called the waist,
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, waspswasp,
name applied to many winged insects of the order Hymenoptera, which also includes ants and bees. Most wasps are carnivorous, feeding on insects, grubs, or spiders. They have biting mouthparts, and the females have stings with which they paralyze their prey.
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, and termitestermite
or white ant,
common name for a soft-bodied social insect of the infraorder Isoptera. Originally classified in as a separate order, termites are genetically related to cockroaches and are now classified with them in the order Blattodea.
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) are legless but otherwise grublike. Although all social-insect larvae are ultimately dependent on the parent colony for food, they are considered true larvae because they pass through a pupal stage.

Larva

 

a stage in the individual development of many invertebrates and some vertebrates (fishes and amphibians) in which the nutrient reserves of the egg are insufficient to complete embryonic development.

An organism in the larval stage is self-sufficient. Usually it has special organs not characteristic of the adult form but lacks other organs characteristic of the adult. In many animals, the existence of the larval stage is determined by the differences in the modes of life of the early stages of development and that of the adult stage; thus, the trochophore, characteristic of polychaetes and many mollusks, is free-swimming, but the adult form is benthic. The presence of a larva is sometimes associated with a change in habitat in the course of development. For example, many amphibian larvae are adapted to aquatic life, whereas the adult animals are adapted to dry land. In sessile or sluggish marine animals, a free-swimming larva ensures offspring distribution. This is true of the larvae of sponges and coelenterates (paren-chymula, amphiblastula, planula) and of echinoderms and enteropneusts (dipleurula).

The metamorphosis of the larva to the adult animal consists in the restructuring of the larva’s organization; the more profound that restructuring, the greater will be the difference between the larva and the adult organism. The changes that occur in the metamorphosis of certain invertebrates (nemertines, echinoderms, and insects) are especially pronounced. For example, in higher insects in the pupal stage (which follows the larval stage), almost all of the larval organs are destroyed. The organs of the adult animal are formed de novo from special rudiments called imaginal disks. The larvae of some animals retain the structural characteristics of ancestral forms. For example, phylogenetic significance of this sort is ascribed to the larvae of sponges and coelenterates (parenchymula, planula) and to the caudate larvae of ascidians, which resemble a free-swimming ancestor in structure.

A. V. IVANOV

larva

[′lär·va] (invertebrate zoology) An independent, immature, often vermiform stage that develops from the fertilized egg and must usually undergo a series of form and size changes before assuming characteristic features of the parent.

larva

an immature free-living form of many animals that develops into a different adult form by metamorphosis

larva


larva

 [lahr´vah] (pl. lar´vae) (L.) 1. an independent, immature stage in the life cycle of an animal, in which it is markedly unlike the parent and must undergo changes in form and size to reach the adult stage.2. something that resembles such an immature animal.larva cur´rens a rapidly progressive eruption" >creeping eruption caused by autoinoculation of larvae of Strongyloides stercoralis that migrate to and mature at the anus in intestinal infections with the parasite.cutaneous larva mi´grans (larva mi´grans) a convoluted threadlike skin eruption that appears to migrate, caused by the burrowing beneath the skin of roundworm larvae, particularly of the species Ancylostoma; similar lesions are caused by the larvae of botflies" >botflies. Called also creeping eruption.ocular larva migrans infection of the eye with larvae of the roundworm Toxocara canis or T. cati, which may lodge in the choroid or retina or migrate to the vitreous; on the death of the larvae, a granulomatous inflammation occurs, the lesion varying from a translucent elevation of the retina to massive retinal detachment and pseudoglioma.visceral larva migrans a condition due to prolonged migration by the skin larvae of animal nematodes in human tissue other than skin; commonly caused by larvae of the roundworms Toxocara canis and T. cati.

lar·va

, pl.

lar·vae

(lar'vă, lar'vē), 1. The wormlike developmental stage or stages of an insect or helminth that are markedly different from the adult and undergo subsequent metamorphosis; a grub, maggot, or caterpillar. 2. The second stage in the life cycle of a tick; the stage that hatches from the egg and, following engorgement, molts into the nymph. 3. The young of fishes or amphibians that often differ in appearance from the adult. [L. a mask]

larva

(lär′və)n. pl. lar·vae (-vē) or lar·vas 1. a. The newly hatched, wingless, often wormlike form of many insects, developing into a pupa in species that undergo complete metamorphosis.b. The six-legged immature form of a tick or mite.2. The newly hatched, earliest form of any of various animals that undergo metamorphosis, differing markedly in appearance from the adult.
lar′val adj.

lar·va

, pl. larvae (lahr'vă, -vē) 1. Developmental stage or stages of an insect or helminth. 2. The second stage in the life cycle of a tick; the stage in which it hatches from the egg and, following engorgement, molts into the nymph. 3. The young of fishes or amphibians that often differ in appearance from the adult. [L. a mask]

larva

(pl. larvae) the preadult form of many animals that is usually morphologically different from the adult, and which in many cases takes up the larger part of the life history. Usually the larva is not sexually mature, but in cases of PAEDOGENESIS, of which the AXOLOTL is an example, breeding may take place at this stage. Often the larva is a dispersal phase, as in many marine invertebrates where larvae occur in the PLANKTON and usually the larva feeds in a different way from the adult and does not compete with it.

Larva

The immature, early form of an organism that at birth or hatching is not like its parent and has to undergo metamorphosis before assuming adult features.Mentioned in: Antihelminthic Drugs, Hookworm Disease, Trichinosis

LARVA


AcronymDefinition
LARVALow Altitude Research Vehicle for the Air Force

larva


  • noun

Words related to larva

noun the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose

Related Words

  • animal
  • animate being
  • beast
  • creature
  • fauna
  • brute
  • ascidian tadpole
  • bladder worm
  • cercaria
  • wireworm
  • mealworm
  • wiggler
  • wriggler
  • jointworm
  • strawworm
  • ant lion
  • antlion
  • doodlebug
  • aphid lion
  • aphis lion
  • dobson
  • hellgrammiate
  • caseworm
  • caterpillar
  • nymph
  • leptocephalus
  • bot
  • grub
  • polliwog
  • pollywog
  • tadpole
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