A larva is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
Lepidoptera is an order of insects that includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing ten percent of the total described species of living organisms, and placed in 126 families and 46 superfamilies. It is one of the most widespread and widely recognizable insect orders in the world. The Lepidoptera show many variations of the basic body structure that have evolved to gain advantages in lifestyle and distribution. Recent estimates suggest the order may have more species than earlier thought, and is among the four most species-rich orders, along with the Hymenoptera, Diptera, and Coleoptera.
Flies are insects of the order Diptera, the name being derived from the Greek δι- di- "two", and πτερόν pteron "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing an estimated 1,000,000 species including horse-flies, crane flies, hoverflies, mosquitoes and others, although only about 125,000 species have been described.
Hover flies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the larvae (maggots) eat a wide range of foods. In some species, the larvae are saprotrophs, eating decaying plant and animal matter in the soil or in ponds and streams. In other species, the larvae are insectivores and prey on aphids, thrips, and other plant-sucking insects.
Wuchereria bancrofti is a filarial (arthropod-borne) nematode (roundworm) that is the major cause of lymphatic filariasis. It is one of the three parasitic worms, together with Brugia malayi and B. timori, that infect the lymphatic system to cause lymphatic filariasis. These filarial worms are spread by a variety of mosquito vector species. W. bancrofti is the most prevalent of the three and affects over 120 million people, primarily in Central Africa and the Nile delta, South and Central America, the tropical regions of Asia including southern China, and the Pacific islands. If left untreated, the infection can develop into lymphatic filariasis. In rare conditions, it also causes tropical pulmonary eosinophilia. No vaccine is commercially available, but high rates of cure have been achieved with various antifilarial regimens, and lymphatic filariasis is the target of the World Health Organization Global Program to Eliminate Lymphatic Filariasis with the aim to eradicate the disease as a public-health problem by 2020. However, this goal was not met by 2020.
Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay their eggs. The name is associated especially with the Tenthredinoidea, by far the largest superfamily in the suborder, with about 7,000 known species; in the entire suborder, there are 8,000 described species in more than 800 genera. Symphyta is paraphyletic, consisting of several basal groups within the order Hymenoptera, each one rooted inside the previous group, ending with the Apocrita which are not sawflies.
Dermestidae are a family of Coleoptera that are commonly referred to as skin beetles. Other common names include larder beetle, hide or leather beetles, carpet beetles, and khapra beetles. There are over 1,800 species described.
Gnathostomiasis, also known as larva migrans profundus, is the human infection caused by the nematode Gnathostoma spinigerum and/or Gnathostoma hispidum, which infects vertebrates.
The caddisflies, or order Trichoptera, are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis of the adult mouthparts. Integripalpian larvae construct a portable casing to protect themselves as they move around looking for food, while annulipalpian larvae make themselves a fixed retreat in which they remain, waiting for food to come to them. The affinities of the small third suborder Spicipalpia are unclear, and molecular analysis suggests it may not be monophyletic. Also called sedge-flies or rail-flies, the adults are small moth-like insects with two pairs of hairy membranous wings. They are closely related to the Lepidoptera which have scales on their wings; the two orders together form the superorder Amphiesmenoptera.
The Lymexylidae, also known as ship-timber beetles, are a family of wood-boring beetles. Lymexylidae belong to the suborder Polyphaga and are the sole member of the superfamily Lymexyloidea.
The soldier flies are a family of flies. The family contains over 2,700 species in over 380 extant genera worldwide. Larvae are found in a wide array of locations, mostly in wetlands, damp places in soil, sod, under bark, in animal excrement, and in decaying organic matter. Adults are found near larval habitats. They are diverse in size and shape, though they commonly are partly or wholly metallic green, or somewhat wasplike mimics, marked with black and yellow or green and sometimes metallic. They are often rather inactive flies which typically rest with their wings placed one above the other over the abdomen.
The family Oedemeridae is a cosmopolitan group of beetles commonly known as false blister beetles, though some recent authors have coined the name pollen-feeding beetles. There are some 100 genera and 1,500 species in the family, mostly associated with rotting wood as larvae, though adults are quite common on flowers. The family was erected by Pierre André Latreille in 1810.
Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.
The Sciaridae are a family of flies, commonly known as dark-winged fungus gnats. Commonly found in moist environments, they are known to be a pest of mushroom farms and are commonly found in household plant pots. This is one of the least studied of the large Diptera families, probably due to the small size of these insects and the similarity among species.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
The Brachypsectridae are a family of beetles commonly known as the Texas beetles. There are only two extant genera, Brachypsectra and Asiopsectra. Brachypsectra has a cosmopolitan distribution, mostly in arid regions, while Asiopsectra is found in Central Asia and the Middle East.
Ichthyoplankton are the eggs and larvae of fish. They are mostly found in the sunlit zone of the water column, less than 200 metres deep, which is sometimes called the epipelagic or photic zone. Ichthyoplankton are planktonic, meaning they cannot swim effectively under their own power, but must drift with the ocean currents. Fish eggs cannot swim at all, and are unambiguously planktonic. Early stage larvae swim poorly, but later stage larvae swim better and cease to be planktonic as they grow into juveniles. Fish larvae are part of the zooplankton that eat smaller plankton, while fish eggs carry their own food supply. Both eggs and larvae are themselves eaten by larger animals.
Eulichadidae is a family of beetles belonging to Elateriformia. There are two extant genera, Eulichas with several dozen species native to the Indomalayan realm of Asia, and Stenocolus, with a single species native to Western North America. The larvae are aquatic, with the larvae of Eulichas being found in sandy sediments of clean forest streams, while the larvae of Stenocolus are found under rocks and in leaf packs in low elevation streams and rivers. They are herbivious/saprophagous with larval specimens of Eulichas having been found with wood particles in their stomachs, while the larvae of Stenocolus are known to feed on decaying roots and detritus. The adults are terrestrial, with specimens of Eulichas typically found using light, while specimens of Stenocolus are typically found in riparian vegetation, and are not attracted to light. Potential extinct genera have been described from Mesozoic rocks, but the placement of several of these taxa in the family is disputed.
Oreoleptidae is a family of flies. The family was established in 2005 on the basis of the type species Oreoleptis torrenticola placed in the monotypic genus Oreoleptis. The only known species was collected from the Rocky Mountains where the larvae grow in torrential streams. Larvae have also been found in groundwater wells. The larvae are similar to those of Athericidae and Tabanidae but with long crocheted false-legs (prolegs) arising from abdominal segments 2-7. The larvae have hollow mandibular hooks.
Hookworms are intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases. Hookworm infection is found in many parts of the world, and is common in areas with poor access to adequate water, sanitation, and hygiene. In humans, infections are caused by two main species of roundworm, belonging to the genera Ancylostoma and Necator. In other animals the main parasites are species of Ancylostoma. Hookworm is closely associated with poverty because it is most often found in impoverished areas, and its symptoms promote poverty through the educational and health effects it has on children. It is the leading cause of anemia and undernutrition in developing countries, while being one of the most commonly occurring diseases among poor people. Hookworm thrives in areas where rainfall is sufficient and keeps the soil from drying out, and where temperatures are higher, making rural, coastal areas prime conditions for the parasite to breed.
