Larvae

thumb|Euthalia aconthea (baron butterfly) caterpillar found in India thumb|Caterpillar of Papilio machaon thumb|upright|A monarch butterfly (Danaus plexippus) caterpillar feeding on an unopened seed pod of [[swamp milkweed]]

thumb|286x286px|Common frog (Rana temporaria) tadpole

thumb|250px|Larva of the Papilio xuthus [[butterfly]] thumb|Eurosta solidaginis goldenrod gall fly larva

thumb|Mealworms, larvae of Tenebrio molitor, illustrated by Des Helmore

thumb|Maggots on a porcupine carcass thumb|Maggots feeding on an opossum [[carrion]] thumb|Common wild pig (boar) corpse decomposition timelapse. Maggots are visible. A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, hoverflies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and crane flies.

right|thumb|The anatomy of a trochophore A - episphere B - hyposphere 1 - ganglion|ganglia 2 - apical tuft 3 - prototroch 4 - metatroch 5 - nephridium 6 - anus 7 - protonephridia 8 - gastrointestinal tract 9 - buccal opening 10 - [[blastocoele]]

A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and some species of Ctenophores, which are not closely related to cnidarians. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva. In a few cnidarian clades, like Aplanulata and the parasitic Myxozoa, the planula larval stage has been lost.

crustacean larval stage

thumb|9 day old veliger of the nudibranch Tritonia diomedea with various organs and structures labeled. Larval size about 200 um on its long axis. thumb|Veliger of sea hare [[Dolabrifera dolabrifera, with two rows of cilia visible]]

right|thumb|200px|A drawing of the glochidium of the swan mussel ([[Anodonta cygnea). The larva is 0.35 mm long]] right|thumb|200px|Glochidia of the mussel Lampsilis higginsii

A cercaria (plural cercariae) is a larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. A cercaria has a tapering head with large penetration glands. It may or may not have a long swimming "tail", depending on the species. The motile cercaria finds and settles in a host where it will become either an adult, or a mesocercaria, or a metacercaria, according to species.

thumb|upright|left|J: medial prolegsK: anal proleg(F, G, and H: true legs) thumb|upright=1|right|Lepidoptera: Papilio machaon caterpillar with four pairs of medial prolegs and a pair of anal prolegs thumb|upright=1|right|Hymenoptera: Craesus septentrionalis caterpillars with seven pairs of prolegs A proleg is a small, fleshy, stub structure found on the ventral surface of the abdomen of most larval forms of insects of the order Lepidoptera, though they can also be found on larvae of insects such as sawflies. In all the orders in which they appear, mainly Hymenoptera and Lepidoptera, prolegs of

thumb|300px|Leptocephalus larva A leptocephalus (meaning "slim head") is the flat and transparent larva of eels and other members of the superorder Elopomorpha. This is one of the most diverse groups of teleosts, containing 801 species in 4 orders, 24 families, and 156 genera. This group is thought to have arisen in the Cretaceous period over 140 million years ago.

thumb|right|220px|The cutworm larva of the large yellow underwing (Noctua pronuba) Cutworms are moth larvae that hide under litter or soil during the day, coming out in the dark to feed on plants. A larva typically attacks the first part of the plant it encounters, namely the stem, often of a seedling, and consequently cuts it down, hence the name cutworm. Cutworms are not worms, biologically speaking, but caterpillars.

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thumb|right| Drawing of Cysticerus cellulosae: Left one from the pig showing an invaginated scolex. Right one from human intestine showing the evaginated scolex. Cysticercus (pl. cysticerci) is a scientific name given to the young tapeworms (larvae) belonging to the genus Taenia. It is a small, sac-like vesicle resembling a bladder; hence, it is also known as bladder worm. It is filled with fluid, in which the main body of the larva, called scolex (which will eventually form the head of the tapeworm), resides. It normally develops from the eggs, which are ingested by the intermediate hosts, su

right|thumb|Bipinnaria larva A bipinnaria is the first stage in the larval development of most starfish, and is usually followed by a brachiolaria stage. Movement and feeding is accomplished by the bands of cilia. Starfish that brood their young generally lack a bipinnaria stage, with the eggs developing directly into miniature adults.

larval form of trematodes

thumb|right|Plerocerci of Callitetrarhynchus gracilis in the body cavity of the fish [[Scomberomorus commerson]]

thumb|300px|Larvicide CULINEX Tab plus, Bacillus thuringiensis israelensis A larvicide (alternatively larvacide) is an insecticide that is specifically targeted against the larval life stage of an insect. Their most common use is against mosquitoes. Larvicides may be contact poisons, stomach poisons, growth regulators, or (increasingly) biological control agents.

The procercoid is the second larval stage of some tapeworms, which typically develops inside of copepods following their ingestion of the coracidium parasite structure that contains the larval oncosphere. The flatworm in this stage is not enclosed in a protective cyst, but is infectious to the next intermediate host. Procercoids resemble their adult forms in pathways of energy metabolism. They are basically anaerobic, lacking a complete Krebs cycle, and rely on glycolysis.

thumb|General description of the egg and oncosphere of Echinococcus spp.

A cysticercoid is the larval stage of certain tapeworms, similar in appearance to a cysticercus, but having the scolex filling completely the enclosing cyst. In tapeworm infections, cysticercoids can be seen in free form as well as enclosed by cysts in biological tissues such as the intestinal mucosa. Also referred to as metacestodes, they produce proteins enabling them to invade and to survive in the host. It is typically associated with cyclophyllid tapeworms that have an invertebrate intermediate host, but can appear in humans during the autoinfective cycle of Hymenolepis nana.

thumb|right|250px|Older brachiolaria larva of Asterias sp. from below, anterior end at topFrom [[Ernst Haeckel's Kunstformen der Natur (1904)]] A brachiolaria is the second stage of larval development in many starfishes. It follows the bipinnaria. Brachiolaria have bilateral symmetry, unlike the adult starfish, which have a pentaradial symmetry. Starfish of the order Paxillosida (Astropecten and Asterina) have no brachiolaria stage, with the bipinnaria developing directly into an adult.

crustacean larval and immature stages between hatching and adult form

thumb|right|A tornaria larva

thumb|Deceptively caterpillar-like eruciform larvae of typical symphytan thumb|Larva of a trichopteran, extended part-way out of its case

REDIRECT Peracarida#Manca

juvenile form of some flatworms

Developmental stage present in certain nematodes

thumb|Planidia and larva of a parasitoid wasp of the Perilampidae family. thumb|Triungulin, later larval, and other instars of a Blister beetle|Meloid beetle. thumb|Planidia of a Meloidae|Meloid beetle in opportunistic phoresy on a male solitary bee ([[Andrena carlini), awaiting contact with a female, whose nest they then could invade.]] A planidium is a specialized form of insect larva seen in the first-instar of a few families of insects that have parasitoidal ways of life. They are usually flattened, highly sclerotized (hardened), and quite mobile. The function of the planidial stage is to

400px|thumb|right|Diagrammatic reconstruction of Dipleurula from Encyclopædia Britannica, 1911, adapted from Bather, 1900. Bather drew the creature as crawling on the sea-floor, but echinoderm larvae are usually pelagic (free-floating). The ciliated bands are not drawn. Dipleurula is a hypothetical larva of the ancestral echinoderm. It represents the type of basis of all larval forms of, at least, the eleutherozoans (all echinoderms except crinoids), where the starfish, sea urchins, sea cucumbers and brittle stars belong. The dipleurula is a bilaterally symmetrical, ciliated echinoderm larva (