Aquatic-larvae
Guides
Anasimyia
swamp flies
Anasimyia is a genus of wetland hoverflies (Syrphidae) characterized by aquatic larval development. The genus was historically treated as a subgenus of Lejops but has been elevated to full generic status based on morphological and molecular evidence. Adults are associated with marshy and aquatic habitats. The genus includes approximately 20 described species distributed primarily across the Holarctic region.
Anasimyia chrysostoma
Lump-legged Swamp Fly
Anasimyia chrysostoma, commonly known as the lump-legged swamp fly, is a syrphid fly species distributed across the United States and Canada. Adults are flower visitors that feed on nectar and pollen. The larvae are aquatic and possess the characteristic rat-tailed morphology typical of the genus Anasimyia. The species is considered fairly common and has been documented in 355 observations on iNaturalist.
Anasimyia distincta
short-spurred swamp fly
Anasimyia distincta, known as the short-spurred swamp fly, is a rare syrphid fly species documented in the northeastern United States and adjacent Canada. Adults are commonly observed on flowers where they feed on nectar and pollen. The species belongs to a genus whose larvae are aquatic and possess the characteristic rat-tailed morphology of eristaline hoverflies.
Antocha
Antocha is a genus of crane flies (Limoniidae) comprising approximately 161 species across three subgenera. The genus is globally distributed with highest diversity in the Oriental (83 species) and East Palearctic (53 species) regions. Larvae are aquatic and rheophilic, inhabiting fast-flowing streams and rivers where they construct silken tubes on submerged rocks. The genus exhibits notable sensitivity to hydrological disturbances, making it a potential indicator of stream ecosystem health.
Atrichopogon peregrinus
biting midge
Atrichopogon peregrinus is a species of biting midge in the family Ceratopogonidae. The specific epithet "peregrinus" (Latin for "wanderer" or "foreigner") suggests a potentially wide-ranging or introduced distribution, though detailed geographic records remain limited. As a member of the genus Atrichopogon, it belongs to a diverse group of small, blood-feeding flies commonly known as no-see-ums or punkies. The species was described by Johannsen in 1908, indicating it has been recognized in scientific literature for over a century, though comprehensive biological studies appear sparse.
Bellura
Bellura is a genus of moths in the family Noctuidae, established by Walker in 1865. The genus contains approximately eight described species distributed in North America. Caterpillars of at least some species are aquatic or semi-aquatic, feeding on aquatic plants such as water lilies. The genus is notable among Noctuidae for this aquatic larval ecology, which is relatively uncommon in the family.
Bezzia perplexa
Bezzia perplexa is a species of biting midge in the family Ceratopogonidae, described by Dow and Turner in 1976. The genus Bezzia comprises non-blood-feeding ceratopogonids whose larvae develop in aquatic or semi-aquatic habitats. As a member of the Palpomyiini tribe, this species shares characteristics with other predatory or detritivorous biting midges. Published records for this species are limited.
Bittacomorpha occidentalis
Western Phantom Crane Fly
Bittacomorpha occidentalis is a species of phantom crane fly in the family Ptychopteridae. This dipteran belongs to a group known for their distinctive hovering flight behavior and elongated legs. The species was described by Aldrich in 1895. Like other members of the genus Bittacomorpha, adults are characterized by their striking black-and-white banded legs and unique flight pattern where they appear to drift with legs extended. The larvae develop in aquatic or semi-aquatic environments, typical for the family.
Chrysogaster
Low-horned Wrinkleheads
Chrysogaster is a genus of small hoverflies in the subfamily Eristalinae. Adults are dark or black with shiny colorful reflections and visit flowers in damp marshy areas. The aquatic larvae possess a short posterior breathing siphon, shorter than that of related genera such as Eristalis. Several related genera—Melanogaster, Orthonevra, Lejogaster, and Riponnensia—were formerly classified within Chrysogaster.
Chrysops dacne
Chrysops dacne is a species of deer fly in the family Tabanidae, described by Philip in 1955. The species name is a playful reference, sounding like 'balls of fire' when pronounced. Like other members of the genus Chrysops, it is likely a biting fly with aquatic or semi-aquatic larval stages, though specific details about this particular species remain poorly documented in available literature.
Chrysops nigripes
Chrysops nigripes is a species of deer fly in the family Tabanidae, first described by Zetterstedt in 1838. Larval development has been documented in subarctic peatland environments, where the species occupies aquatic to semi-aquatic microhabitats. Life cycle completion at subarctic latitudes may require 7–8 years, indicating exceptionally slow growth rates compared to temperate populations of related species.
Culicidae
mosquitoes, mosquito
Culicidae, commonly known as mosquitoes, is a family of small flies in the order Diptera. Females of most species are ectoparasites that feed on vertebrate blood using specialized piercing-sucking mouthparts, while males feed exclusively on plant nectar and other sugar sources. The family includes thousands of species distributed worldwide, with many serving as vectors for significant human and animal diseases including malaria, yellow fever, dengue, and West Nile virus. Mosquitoes require standing water to complete their aquatic larval and pupal stages.
Dicranota
Dicranota is a genus of crane flies (Diptera: Pediciidae) established by Zetterstedt in 1838. The genus contains multiple subgenera, including Eudicranota and Rhaphidolabis. Species occur across the Northern Hemisphere, with documented records from Europe, Korea, the Caucasus, and Central Asia. Larvae are aquatic and predatory, inhabiting cold, clean streams and springs.
Elophila nebulosalis
Nebulous Munroessa Moth
Elophila nebulosalis is a moth species in the family Crambidae, described by Charles H. Fernald in 1887. It is restricted to the southeastern United States, with records from South Carolina to Florida. The larvae are thought to be aquatic, consistent with other members of the subfamily Acentropinae.
Eristalinae
Drone Flies and Allies
Eristalinae is a subfamily of hoverflies (Syrphidae) comprising approximately nine tribes and notable for exceptional Batesian mimicry of bees and wasps. Adults are important pollinators, while larvae exhibit the greatest habitat diversity among hoverflies, occupying aquatic environments, decaying organic matter, sap runs, and even wasp nests. The subfamily includes the well-known drone fly (Eristalis tenax), whose larvae—called rat-tailed maggots—possess an extendable posterior breathing siphon.
Eristalini
Rat-tail Maggot Flies
Eristalini is a tribe of hoverflies (Syrphidae) characterized by larvae known as "rat-tailed maggots," which possess a posterior telescopic breathing siphon. Several species are notable hymenopteran mimics: Eristalis species resemble honeybees, while Helophilus and Parhelophilus display wasp-like yellow and black striping. Adults function as pollinators, while larvae inhabit aquatic or semi-aquatic environments rich in decaying organic matter.
Eristalinus
Lagoon Flies
Eristalinus is a genus of hoverflies (family Syrphidae) characterized by distinctive spotted or banded eye patterns in most species. These stout, nimble fliers are distributed across Europe, Africa, Asia, and the Americas, with several species becoming widespread invasives outside their native ranges. The genus has undergone taxonomic revision, with molecular and morphological studies reorganizing former subgenera Eristalodes and Lathyrophthalmus into two primary clades. Species such as E. taeniops and E. aeneus are notable for their rapid global spread and potential as managed pollinators in agricultural systems.
Eristalinus aeneus
Common Lagoon Fly
Eristalinus aeneus is a hoverfly (Syrphidae) with subcosmopolitan distribution, commonly found in freshwater habitats including coastal lagoons, ponds, and slow-moving rivers. Adults are effective pollinators of crops including watermelon and mango, and have been evaluated as managed pollinators in protected agriculture. The species exhibits distinctive patterned eyes with black spots, metallic coloration, and rapid hovering flight. Larvae develop in aquatic or semi-aquatic environments with decaying organic matter, possessing a characteristic extensible breathing siphon.
Eristalis
Drone Flies, Droneflies
Eristalis is a large genus of hoverflies (family Syrphidae) comprising approximately 99 species. Adults are commonly called drone flies due to their resemblance to honeybee drones, a form of Batesian mimicry that provides protection from predators. The larvae, known as rat-tailed maggots, are aquatic and possess an extendable breathing siphon that allows them to inhabit oxygen-depleted environments such as stagnant water, sewage, and decomposing organic matter. Adults are important generalist pollinators, with some species proposed as managed alternatives to honey bees for agricultural pollination.
Eristalis brousii
Hourglass Drone Fly
Eristalis brousii, commonly known as the hourglass drone fly, is a hoverfly species first described by Samuel Wendell Williston in 1882. The species has experienced severe population decline across North America following the introduction of the European congener Eristalis arbustorum near Toronto around 1885. As of 2019, it persists only along the lake margin of Hudson Bay in Northern Canada, making it one of the most geographically restricted hoverflies on the continent. Like other Eristalis species, adults are pollinators while larvae develop as aquatic filter-feeders.
Eristalis flavipes
orange-legged drone fly
Eristalis flavipes, commonly known as the orange-legged drone fly, is a North American hoverfly in the family Syrphidae. Adults are striking mimics of bumblebees, measuring 13–17 mm in length, with abundant bright yellow pile on a black body and distinctive orange-red legs. The species is active from early April through mid-October, occurring across diverse habitats with particular affinity for wetlands. Adults visit flowers for nectar and pollen, while larvae are aquatic rat-tailed maggots that filter-feed in standing water.
Eristalis fratercula
Eristalis fratercula is a species of drone fly in the family Syrphidae, described by McNeill. It belongs to a genus of hoverflies known for Batesian mimicry of bees and wasps. The species is listed in grasshopper survey records from Colorado and Wyoming, suggesting it occurs in western North American grasslands. Like other Eristalis species, adults are likely pollinators and larvae develop in aquatic or semi-aquatic organic-rich habitats.
Eristalis rupium
Spot-winged Drone Fly
Eristalis rupium, the spot-winged drone fly, is a European hoverfly species first described by Fabricius in 1805. It is a common species across Europe and uncommon in North America. Like other Eristalis species, it exhibits Batesian mimicry of honey bees and serves as an important pollinator. The larvae are aquatic filter-feeders of the rat-tailed type, inhabiting clear-water streams.
Eulichadidae
Forest Stream Beetles
Eulichadidae is a small family of beetles within Elateriformia, comprising two extant genera with contrasting distributions: Eulichas (Indomalayan realm, Asia) and Stenocolus (Western North America). Adults are terrestrial, while larvae are obligately aquatic in forest streams. The family exhibits notable ecological divergence between genera in habitat use and adult behavior.
Eurimyia
rat-tail maggot flies, swamp flies
Eurimyia is a genus of hoverflies (family Syrphidae) containing three described species. These flies are commonly known as rat-tail maggot flies due to the distinctive elongated breathing tube of their aquatic larvae. The genus was established by Bigot in 1883 and previously included species now classified under Lejops. Adults are associated with wetland habitats.
Hedriodiscus leucogaster
Hedriodiscus leucogaster is a species of soldier fly in the family Stratiomyidae, described by James in 1933. The genus Hedriodiscus is closely related to Psellidotus; these two genera are readily distinguishable in the Nearctic region but their distinction becomes less clear in the Neotropics, particularly in South America. Most species in both genera are poorly known beyond their original descriptions. Larvae of the subfamily Stratiomyinae are aquatic, and adults of this subfamily often exhibit patterned eyes with horizontal banding, suggesting an ability to detect horizontally polarized light.
Hedriodiscus varipes
Hedriodiscus varipes is a species of soldier fly in the family Stratiomyidae. The genus Hedriodiscus belongs to the subfamily Stratiomyinae, whose larvae are known to be aquatic. Adults of related species in this subfamily exhibit patterned eyes with horizontal banding, suggesting an ability to detect horizontally polarized light. The species is distributed in Canada and the United States.
Helophilina
rat-tail maggot flies
Helophilina is a subtribe of hoverflies within the family Syrphidae, commonly referred to as rat-tail maggot flies. The subtribe encompasses approximately 19 genera and over 180 described species. Members are classified within the subfamily Eristalinae and tribe Eristalini. The common name derives from the aquatic or semi-aquatic larval stage, which possesses a long, telescopic breathing siphon resembling a rat's tail.
Helophilus
Marsh Flies, Tiger Hoverflies
Helophilus is a genus of moderate to large hoverflies in the family Syrphidae, commonly known as marsh flies or tiger hoverflies. Adults are notable bee or wasp mimics with distinctive lengthwise yellow stripes on the thorax and transverse bands on the abdomen. Larvae are aquatic "rat-tailed maggots" that filter-feed on microorganisms in organic-rich water. The genus comprises two subgenera: Helophilus and Pilinasica (the latter containing endemic New Zealand species).
Helophilus bottnicus
Gray-banded Marsh Fly
Helophilus bottnicus is a hoverfly in the family Syrphidae, commonly known as the Gray-banded Marsh Fly. It belongs to a genus whose larvae are aquatic, developing in decaying organic matter submerged in water. Adults are sun-loving and often exhibit yellowjacket mimicry with characteristic thoracic striping. The species was described by Wahlberg in 1844 and is recorded from Norway and Sweden.
Helophilus intentus
Yellow-legged Marsh Fly
Helophilus intentus is a species of syrphid fly (flower fly) in the family Syrphidae. It belongs to the genus Helophilus, whose members are commonly known as marsh flies due to their association with aquatic habitats. The larvae develop in decaying plant matter submerged in water. Adults are sun-loving and frequently observed visiting flowers for nectar and pollen.
Helophilus latifrons
Broad-headed Marsh Fly
Helophilus latifrons, commonly known as the Broad-headed Marsh Fly, is a species of syrphid fly in the family Syrphidae. Adults are flower visitors that obtain nectar and pollen from blossoms. The larvae are aquatic and develop in decaying submerged vegetation, functioning as decomposers in wetland ecosystems. The species occurs across much of North America including the United States, southern Canada, and mountainous regions of Mexico.
Helophilus neoaffinis
Northwestern Marsh Fly
A syrphid fly species in the genus Helophilus, recognized by iNaturalist as the Northwestern Marsh Fly. As with other members of its genus, it likely exhibits yellowjacket mimicry with vertical yellow stripes on the thorax. The larvae develop in decaying plant matter submerged in water, characteristic of the 'rat-tailed maggot' form found in aquatic or semi-aquatic habitats.
Hoplitimyia
Hoplitimyia is a genus of soldier flies (family Stratiomyidae) established by James in 1934. The genus comprises approximately ten described species distributed across the Americas, with records from both North and South America. Species within this genus exhibit the characteristic features of the subfamily Stratiomyinae, including patterned eyes and wasp-mimicking coloration. Larvae are aquatic, a trait common to the subfamily.
Hoplitimyia constans
Hoplitimyia constans is a species of soldier fly in the family Stratiomyidae, distributed in the United States. The genus Hoplitimyia includes species with aquatic larvae and adults that often exhibit wasp-mimicking coloration and behavior. Members of this genus are known for their flighty behavior and attraction to flowers. The specific epithet "constans" was established by Loew in 1872, originally described under the genus Stratiomyia.
Hoplitimyia sp-near-mutabilis
A wasp-mimicking soldier fly in the family Stratiomyidae, originally misidentified as a vespid wasp due to its black and yellow coloration and flight behavior. The species exhibits striking, sexually dimorphic eye patterns and has aquatic larvae. Adults are highly active and reluctant to settle, making observation and photography challenging. The specimen discussed was collected in Buenos Aires Province, Argentina, and identified by dipterist Martin Hauser as likely belonging to the genus Hoplitimyia, possibly near H. mutabilis, though species boundaries in this group remain unresolved.
Hoplitimyia subalba
Hoplitimyia subalba is a species of soldier fly in the family Stratiomyidae, first described by Walker in 1854. The genus Hoplitimyia comprises species with aquatic larvae, and adults are known for their wasp-mimicking appearance and patterned compound eyes. This species occurs in South America, with records from the Brazilian states of Amazonas and Pará. Adults are reportedly flighty and difficult to photograph, exhibiting behavior consistent with nectar or pollen feeding when provided sugar solutions in captivity.
Langessa
black langessa moth
Langessa is a monotypic genus of crambid moths in the subfamily Acentropinae, established by Munroe in 1972. The sole species, Langessa nomophilalis (black langessa moth), occurs in the southeastern United States. Adults are small moths with distinctive bronzy-brown forewings and patterned hindwings. Larvae are aquatic, feeding on submerged vegetation.
Leptoconops californiensis
Leptoconops californiensis is a species of biting midge in the family Ceratopogonidae, first described by Wirth & Atchley in 1973. It belongs to the subgenus Brachyconops within the genus Leptoconops. The species is known from California, USA. Like other members of this genus, it is likely a blood-feeding pest with aquatic or semi-aquatic immature stages, though specific details about its biology remain poorly documented.
Libellula incesta
slaty skimmer
Libellula incesta, commonly known as the slaty skimmer, is a dragonfly species in the family Libellulidae native to eastern North America. Adults measure approximately 5.28 cm in length. The species exhibits pronounced sexual dimorphism in coloration: mature males are dark blue with black heads, while females and juveniles display brown abdomens with a darker dorsal stripe. Larvae are specialized inhabitants of lake benthos, and adults are active from June through August.
Limoniidae
Limoniid Crane Flies, Limoniidae, Short-palped Crane Flies
Limoniidae is the largest family of crane flies, comprising over 10,700 species in more than 150 genera. Members are distinguished from other crane flies primarily by their wing posture at rest: wings are typically held folded along the body rather than perpendicular to it. The family includes notable wingless snow flies in the genus Chionea, which are active in winter. Limoniids are generally smaller than other crane flies and occupy diverse habitats worldwide. Recent phylogenetic studies indicate the family is paraphyletic, with some limoniids more closely related to Tipulidae and Cylindrotomidae than to other limoniids.
Mallota
Mimic Flies
Mallota is a Holarctic genus of hoverflies (family Syrphidae) containing approximately 30 described species. Adults are well known for their robust, bee-like appearance, functioning as mimics of bumble bees (Bombus species). The genus has been documented from North America, Europe, and Asia. Larvae develop in water-filled tree holes and other decaying wood cavities.
Mallota bautias
Bare-eyed Bee-mimic Fly
Mallota bautias is a hoverfly (family Syrphidae) native to eastern North America. The species is notable for its exceptional mimicry of bumblebees (genus Bombus), particularly Bombus pennsylvanicus, serving as a classic example of Batesian mimicry in which a harmless species evolves to resemble a stinging model. Adult flies are pollinators, while larvae develop in tree holes filled with water. The species has been the subject of behavioral studies examining how avian predators respond to the mimic and its model.
Mallota diversipennis
A syrphid fly in the tribe Eristalini, described by Curran in 1922. Like other members of the genus Mallota, the larvae develop in water-filled tree holes. Adults are bumble bee mimics and are known to use leaves as platforms for grooming behavior. The specific epithet "diversipennis" refers to variation in wing pattern.
Mallota illinoensis
Midwestern Bee-mimic Fly
Mallota illinoensis is a syrphid fly (family Syrphidae) in the tribe Eristalini, described by Robertson in 1901 from Illinois. The species is a bumble bee mimic, with adults resembling bees in size, coloration, and behavior. Larvae develop in tree holes, where they inhabit water-collecting cavities in rotting wood. The species is part of a genus whose members are associated with aquatic or semi-aquatic larval habitats.
Mallota mississipensis
Eastern Mimic Fly
Mallota mississipensis is a species of hover fly (family Syrphidae) in the subfamily Eristalinae. It is one of approximately 13 species in the genus Mallota found in North America. The species is a bumble bee mimic, exhibiting the black and yellow coloration typical of this defensive mimicry strategy. Like other members of its genus, the larvae develop in aquatic or semi-aquatic environments, specifically in water that collects in tree holes. The species is known from eastern North America, with observations documented in the iNaturalist database.
Mallota posticata
Hairy-eyed Bee-mimic Fly
Mallota posticata is a syrphid fly (family Syrphidae) known for its bumble bee mimicry. The species is documented in Illinois and broader North America, with larvae developing in water-filled tree holes. Adults exhibit grooming behavior on leaves and serve as pollinators.
Mallota sackeni
brown-haltered mimic fly, brown-haltered bee-mimic fly
Mallota sackeni is a species of hover fly (family Syrphidae) native to western North America. The species is known for its bee-mimicry, a common defensive adaptation among syrphid flies. Adults are active pollinators, while larvae develop in aquatic or semi-aquatic environments typical of the tribe Eristalini. The species has been documented from British Columbia to southern California and eastward to Idaho and Utah.
Neoascia metallica
Double-banded Fen Fly
Neoascia metallica is a species of hoverfly (family Syrphidae) found across North America. Adults are commonly observed on flowers, where they feed on nectar and pollen. The species is known for its metallic coloration and association with wetland habitats. Larvae are aquatic, a trait that distinguishes this species from many other syrphid flies.
Neolimnophila placida
Placid Crane Fly
Neolimnophila placida is a crane fly species in the family Limoniidae, subfamily Chioneinae. It is widely distributed across the Holarctic region, occurring in both the Nearctic and Palaearctic realms. The species has been documented from northern North America through much of Europe and across northern Asia to Japan. Like other limoniid crane flies, it is associated with moist habitats where larvae develop in decaying organic matter.