Rat-tailed-maggot
Guides
Blera confusa
Confusing Wood Fly
Blera confusa, commonly known as the Confusing Wood Fly, is a syrphid fly species first described by Johnson in 1913. Adults are flower visitors that feed on nectar and pollen. The larvae are of the rat-tailed type, developing in exuding sap or rot holes of trees. The species is widely distributed across eastern and central North America.
Chrysogaster antitheus
Short-haired Wrinkle Fly, Short-haired Wrinklehead
Chrysogaster antitheus is a small syrphid fly (7–8 mm) found in North America, commonly known as the Short-haired Wrinkle Fly. Adults are flower visitors that feed on nectar and pollen. The larvae are aquatic "rat-tailed" maggots with a short respiratory siphon, inhabiting pond edges and emergent vegetation.
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 arbustorum
Eurasian Drone Fly, European Drone Fly
Eristalis arbustorum is a sexually dimorphic hoverfly species in the family Syrphidae. Females closely mimic small, dark mining bees (Andrenidae), while males exhibit less specific mimicry of wasps and other yellow-black Hymenoptera. The species is abundant across the Northern Hemisphere and has been introduced to North America. Adults are important pollinators that visit diverse flowering plants, while larvae are aquatic filter-feeders known as 'rat-tailed maggots' due to their elongated posterior breathing siphon. The species is known to be migratory in Europe, with populations overwintering in sheltered locations such as cave entrances.
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 hirta
Black-footed Drone Fly
Eristalis hirta, commonly known as the black-footed drone fly, is a syrphid fly species first described by Loew in 1866. It is a common species in Western North America and also occurs in Northern Europe. Like other Eristalis species, it exhibits Batesian mimicry of honey bees, providing protection from predators. The larvae are aquatic filter-feeders with the characteristic rat-tailed morphology, developing in standing water habitats.
Eristalis obscura
Dusky Drone Fly
Eristalis obscura, commonly known as the dusky drone fly, is a species of syrphid fly first described by Loew in 1866. It is widespread across northern North America and extends eastward through Europe to Siberia. The species exhibits the characteristic rat-tailed maggot larval form, with aquatic larvae that function as filter-feeders. Like other members of the genus Eristalis, adults are likely bee mimics, though specific documentation of this behavior for E. obscura is limited.
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.
Eristalis saxorum
Blue-polished Drone Fly
Eristalis saxorum is an uncommon species of syrphid fly (hoverfly) native to eastern North America. Adults are flower visitors, obtaining nectar and pollen from blossoms. The species exhibits typical drone fly characteristics, including bee-mimicry and hovering flight behavior. Larvae are presumed to be of the rat-tailed type, though they have not been formally identified for this species. The species is active from mid-March through late October, with adults overwintering in sheltered locations such as cave entrances.
Eristalis tenax
Common Drone Fly, Drone Fly, Rat-tailed Maggot
Eristalis tenax is a cosmopolitan hoverfly (Syrphidae) and the most widely distributed syrphid species globally, occurring on every continent except Antarctica. Adults are striking mimics of honey bees, exhibiting Batesian mimicry that provides protection from predators. The larval stage, known as the rat-tailed maggot, is aquatic and inhabits polluted water containing organic matter, using an elongated posterior siphon for respiration. Adults are important generalist pollinators, particularly of Asteraceae flowers. The species exhibits strong territorial behavior in males and has been documented to cause rare cases of accidental myiasis in humans.
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 groenlandicus
Black-margined Marsh Fly
Helophilus groenlandicus, commonly known as the Black-margined Marsh Fly, is a hoverfly in the family Syrphidae. Adults are flower visitors that obtain nectar and pollen. The species occurs across the northern Holarctic region. Larval biology is not directly documented for this species, though related Helophilus species develop in wet decaying organic material with rat-tailed maggot morphology.
Helophilus hybridus
hoverfly
Helophilus hybridus is a Palearctic hoverfly species in the family Syrphidae. Adults are medium-sized with distinctive yellow and black abdominal patterning. The species is associated with wetland habitats across northern and central Europe, extending eastward through Russia to the Pacific coast. Larvae develop in aquatic or semi-aquatic environments with organic matter.
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 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.
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.
Palpada agrorum
Double-banded Plushback
Palpada agrorum is a common syrphid fly commonly known as the Double-banded Plushback. Adults are flower visitors that obtain nectar and pollen. Larvae are aquatic filter-feeders of the rat-tailed type, possessing an extensible posterior breathing siphon. The species was first described by Fabricius in 1787 and belongs to the agrorum species group within the genus Palpada.
Palpada albifrons
White-faced Plushback
Palpada albifrons is a rare species of syrphid fly (hoverfly) characterized by its distinctive white-faced appearance and aquatic larval stage. Adults are medium-sized flower flies commonly found on flowers, where they feed on nectar and pollen. The species has a disjunct distribution, occurring from Mexico northward along coastal areas of the United States, with additional records from South America. The larvae are aquatic rat-tailed maggots that inhabit organic-rich standing water.
Palpada mexicana
Golden Plushback
Palpada mexicana, commonly known as the Golden Plushback, is a species of hoverfly in the family Syrphidae. The species was originally described as Eristalis mexicanus by Macquart in 1847 and later transferred to the genus Palpada. As a member of the tribe Eristalini, its larvae are rat-tailed maggots adapted to aquatic or semi-aquatic environments with low oxygen levels. The species has been documented in 1,829 iNaturalist observations, indicating it is relatively well-represented in citizen science records.
Palpada pusilla
Bicolored Plushback
Palpada pusilla is a species of syrphid fly in the family Syrphidae, commonly known as the Bicolored Plushback. It is a member of the tribe Eristalini, which includes species whose larvae are known as "rat-tailed maggots" due to their distinctive posterior breathing siphon. The species has been documented across all 27 states of Brazil based on distribution records. Adult flies are pollinators that visit flowers, while larvae develop in organic-rich aquatic environments.
Palpada texana
Wide-eyed Plushback
Palpada texana is a species of hoverfly (family Syrphidae) in the tribe Eristalini. Like other members of its genus, it is associated with aquatic or semi-aquatic larval habitats typical of the Eristalina subtribe. The species was described by Hull in 1925. Adults are presumably pollinators, though specific behavioral observations for this species are limited.
Palpada undescribed-species-near-furcata
An undescribed species in the hoverfly genus Palpada, closely related to P. furcata. As a member of tribe Eristalini, its larvae are rat-tailed maggots—aquatic larvae with an extensible posterior breathing siphon that allows respiration while living in oxygen-poor, organic-rich waters. The genus Palpada includes species commonly found in urban, suburban, and rural areas in putrid standing water.
Palpada vinetorum
Northern Plushback
Palpada vinetorum is a species of syrphid fly in the family Syrphidae, commonly known as the Northern Plushback. It is a medium-sized flower fly native to the Americas, with adults measuring 10–14 mm in length. The species belongs to the vinetorum species group within the genus Palpada, one of three groups established by Thompson (1981). Adults are notable pollinators that visit flowers, while larvae develop in organic-rich aquatic or semi-aquatic environments. The species is widely distributed across North, Central, and South America.
Sericomyia
Pond Flies
Sericomyia is a genus of large hoverflies in the family Syrphidae, commonly known as pond flies. Species within this genus are notable bee mimics, displaying both short-pile and long-pile coloration patterns. The genus is widespread across boreal forests of the Holarctic region, extending southward at higher elevations into the Oriental and Neotropical regions. Larvae are of the rat-tailed maggot type, specialized for aquatic life in oxygen-poor environments.
Sericomyia bifasciata
Long-nosed Pond Fly
Sericomyia bifasciata, commonly known as the Long-nosed Pond Fly, is an uncommon species of syrphid fly described by Williston in 1887. It belongs to the genus Sericomyia, whose larvae are known as "rat-tailed maggots" with long breathing siphons adapted to aquatic environments. However, the larvae of this particular species remain unknown. Adults have been observed in the northeastern part of North America.
Sericomyia chalcopyga
Sericomyia chalcopyga is a species of syrphid fly (hoverfly) in the family Syrphidae. As a member of the tribe Sericomyiini, its larvae are "rat-tailed maggots" with extensible posterior breathing siphons adapted to aquatic environments. The species was described by Loew in 1863. Like other Sericomyia species, adults are pollinators that visit flowers for nectar and pollen.
Sericomyia flagrans
Spot-winged Pond Fly
Sericomyia flagrans is a North American species of flower fly (Syrphidae) commonly known as the Spot-winged Pond Fly. The genus Sericomyia belongs to the tribe Milesiini within subfamily Eristalinae. Larvae of this genus develop in bog mat pools, where they exhibit the characteristic "rat-tailed maggot" morphology with an extensible posterior breathing siphon. Adults are pollinators that visit flowers for nectar and pollen.
Sericomyia harveyi
Harvey's Pond Fly
Sericomyia harveyi is a hoverfly species in the family Syrphidae, subfamily Eristalinae. The genus Sericomyia is part of the tribe Milesiini and is characterized by larvae that inhabit bog mat pools and other wetland habitats. Adults are pollinators that visit flowers for nectar and pollen. The species was described by Osburn in 1908.
Sericomyia lata
White-spotted Pond Fly
Sericomyia lata is a syrphid fly commonly known as the White-spotted Pond Fly. Adults are medium-sized hoverflies, 11.6–15.2 mm in length, with distinctive black bodies and large white abdominal spots. The species is widespread across North America, with highest concentrations in eastern regions. Like other members of its genus, the larvae develop in aquatic or semi-aquatic habitats and possess the characteristic rat-tailed breathing siphon typical of Sericomyia.
Sericomyia militaris
Narrow-banded Pond Fly
Sericomyia militaris, commonly called the narrow-banded pond fly, is a North American syrphid fly (hoverfly) found across northern regions of the continent. Adults range from 11.7–17.1 mm in length and are primarily black with narrow yellow abdominal markings. The species belongs to a genus whose larvae are known as rat-tailed maggots, possessing a distinctive posterior breathing siphon.
Sericomyia slossonae
Slosson's Pond Fly
Sericomyia slossonae is a species of hoverfly (family Syrphidae) in the tribe Milesiini. The genus Sericomyia is part of the group commonly known as "rat-tailed maggots" due to their larvae possessing an extensible posterior breathing siphon. Larvae of Sericomyia species are known to inhabit bog mat pools. Adults are pollinators that visit flowers for nectar and pollen. The species was described by Curran in 1934 and is accepted as valid.
Sericomyia tolli
Great-nosed Pond Fly
Sericomyia tolli is a species of hoverfly (family Syrphidae) described by Frey in 1915. It belongs to the genus Sericomyia, whose larvae are known as 'rat-tailed maggots' and inhabit aquatic environments. The species is poorly documented in scientific literature, with minimal observational records available.
Sericomyia transversa
Yellow-spotted Pond Fly
Sericomyia transversa is an uncommon syrphid fly found in northeastern North America. Adults, known as hoverflies or flower flies, are capable of nearly motionless flight and are commonly observed visiting flowers for nectar and pollen. The species belongs to a genus whose larvae are known as rat-tailed maggots, possessing an extensible posterior breathing siphon that allows them to inhabit aquatic environments. The species was first described by Osburn in 1926.
Sericomyia vockerothi
Vockeroth's Pond Fly
Sericomyia vockerothi is a species of hoverfly in the family Syrphidae, described by Skevington in 2012. The genus Sericomyia belongs to the tribe Milesiini (formerly Sericomyiini), a group whose larvae are known as "rat-tailed maggots" due to their distinctive posterior breathing siphon. Larvae of related Sericomyia species inhabit bog mat pools and other aquatic environments with organic matter. Adults are pollinators that visit flowers for nectar and pollen. The species is poorly documented in public sources, with only five observations recorded on iNaturalist as of the available data.
Syrphidae
hover flies, flower flies, syrphid flies, drone flies
Syrphidae is a species-rich family of true flies comprising over 6,000 described species worldwide, with approximately 800 species in North America. Adults are commonly known as hover flies, flower flies, or drone flies due to their characteristic hovering flight and frequent flower visitation. Many species exhibit Batesian mimicry of bees and wasps, gaining protection from predators through their resemblance to stinging Hymenoptera. The family provides critical ecosystem services: adults are significant pollinators second only to bees, especially in Arctic climates, while larvae display diverse ecological roles including predation on crop pests and nutrient cycling in aquatic habitats.