Robber-fly
Guides
Cyrtopogon willistoni
Cyrtopogon willistoni is a species of robber fly in the family Asilidae, first described by Curran in 1922. The species has been studied in southwestern Montana, where it functions as an opportunistic predator of small insects. Males exhibit elaborate courtship behavior involving audible airborne visual displays and possess distinctive silvery-white combs of hairs on their foretarsi. The species shows strong thermoregulatory dependence on direct sunlight for sustained flight.
Dasylechia
Dasylechia is a monotypic genus of robber flies (family Asilidae) established by Williston in 1907. The genus contains a single described species, Dasylechia atrox. This robber fly was historically considered ultra-rare, but its known range has expanded significantly through citizen science photography. Observations documented on iNaturalist have become the primary source of distributional data for this species, now outnumbering museum specimens.
Dasylechia atrox
Dasylechia atrox is a species of robber fly (family Asilidae) in the subfamily Laphriinae. Once considered ultra-rare, its true geographic range is now being defined primarily through photographic observations on iNaturalist, which have substantially outnumbered collected specimens. The species belongs to a small genus of distinctive, large-bodied robber flies.
Dicolonus
Dicolonus is a genus of robber flies (family Asilidae) established by Loew in 1866. The genus contains approximately five described species distributed across North America and parts of Asia. As members of Asilidae, species in this genus are predatory flies that capture other insects in flight. The genus is relatively small and understudied compared to other asilid genera.
Dicolonus medius
Dicolonus medius is a species of robber fly in the family Asilidae, described by Adisoemarto and Wood in 1975. The genus Dicolonus belongs to a group of predatory flies characterized by their robust build and predatory habits. Like other asilids, this species is presumed to be an active aerial predator of other insects. Specific biological details for D. medius remain poorly documented in the accessible literature.
Dicolonus nigricentrus
Dicolonus nigricentrus is a species of robber fly (family Asilidae) described from Indonesia in 1975. The genus Dicolonus contains small to medium-sized predatory flies distributed primarily in the Oriental and Australasian regions. This species remains poorly documented in scientific literature, with minimal published information on its biology and ecology. It belongs to a family known for aerial predation on other insects.
Dicolonus simplex
Dicolonus simplex is a species of robber fly (family Asilidae) described by Loew in 1866. As a member of the Diptera order, it possesses a single pair of functional wings with the hindwings reduced to halteres. Robber flies in the genus Dicolonus are aerial predators that capture other insects in flight.
Dicolonus sparsipilosus
Dicolonus sparsipilosus is a species of robber fly described by Back in 1909. It belongs to the genus Dicolonus within the family Asilidae, a group of predatory flies known for their agile flight and ambush hunting behavior. The species is rarely recorded, with minimal observation data available.
Dicranus
Dicranus is a genus of robber flies in the family Asilidae, established by Hermann Loew in 1851. Members of this genus are predatory flies that capture other insects in flight. The genus is relatively small and poorly documented compared to other asilid genera, with limited published information on species-level diversity and biology.
Dicranus jaliscoensis
Dicranus jaliscoensis is a species of robber fly in the family Asilidae, described by Williston in 1901. The species is known from Mexico, with records primarily from the state of Jalisco. Like other Asilidae, it is presumed to be a predatory insect, though specific ecological details remain poorly documented.
Dicropaltum
Dicropaltum is a genus of robber flies established by Martin in 1975. The genus contains six described species distributed in the Americas. These predatory flies belong to the tribe Asilini within the subfamily Asilinae.
Dicropaltum humilis
Dicropaltum humilis is a species of robber fly (family Asilidae) described by Bellardi in 1861. As a member of this predatory fly family, it likely exhibits the characteristic hunting behavior of asilids, capturing other insects in flight. The genus Dicropaltum is recognized in robber fly taxonomy, though detailed species-level documentation appears limited in available sources.
Dicropaltum mesae
Dicropaltum mesae is a species of robber fly in the family Asilidae, originally described as Tolmerus mesae by Tucker in 1907. It belongs to the genus Dicropaltum, a group of predatory flies within the subfamily Asilinae. The species is documented through limited observation records, with 15 observations on iNaturalist. Robber flies in this genus are aerial predators that capture other insects in flight.
Dicropaltum rubicundus
Dicropaltum rubicundus is a species of robber fly in the family Asilidae, a group of predatory flies known for their aggressive hunting behavior. The species was described by Hine in 1909. Robber flies in this family are characterized by their stout bodies, large eyes, and strong legs adapted for capturing prey in flight. Very few specific details about the biology or ecology of D. rubicundus have been documented in available sources.
Dioctria
Dioctria is a genus of robber flies (family Asilidae) in the subfamily Dasypogoninae, forming the tribe Dioctriini alongside Bohartia, Dicolonus, Echthodopa, Eudioctria, and Metadioctria. The genus contains multiple species distributed across the Holarctic region, with documented occurrences in Europe, North America, and Turkey. Species within Dioctria are generally small to medium-sized predatory flies that hunt other insects.
Dioctria henshawi
Dioctria henshawi is a species of robber fly in the family Asilidae, first described by Johnson in 1918. The genus Dioctria belongs to the subfamily Stenopogoninae and contains small to medium-sized predatory flies. Species in this genus are among the more diminutive members of the robber fly family, typically measuring under 10 mm in length. Information regarding the specific biology and distribution of D. henshawi remains limited in available sources.
Dioctria hyalipennis
Stripe-legged Robber Fly
Dioctria hyalipennis is a small Holarctic robber fly (10–14 mm) in the family Asilidae, characterized by distinctive black-and-yellow leg patterning and hyaline wings. Adults are active predators that feed primarily on small wasps, bees, and other insects. The species occupies meadows, hedgerows, and forest edges with shrubs or conifers, and has been introduced to eastern North America from Europe.
Dioctria pleuralis
Dioctria pleuralis is a species of robber fly in the family Asilidae, described by Banks in 1917. The genus Dioctria belongs to the subfamily Stenopogoninae, a group characterized by small to medium-sized predatory flies. Species in this genus are among the more diminutive robber flies in North America.
Dioctria vera
Dioctria vera is a species of robber fly in the family Asilidae, described by Back in 1909. It belongs to the subfamily Dasypogoninae and is currently classified within the genus Dioctria. As a member of the robber flies, it is a predatory dipteran, though specific details about its biology and ecology remain poorly documented in available literature.
Dioctria wilcoxi
Dioctria wilcoxi is a small robber fly (Diptera: Asilidae) described by Adisoemarto and Wood in 1975. It belongs to the genus Dioctria, a group of diminutive predatory flies within the subfamily Stenopogoninae. The species is currently treated as a synonym of Dioctria tenuis. Like other members of this genus, it is among the smallest North American robber flies, measuring approximately 6–8 mm in length. Species in this genus are morphologically similar to Cerotainia but can be distinguished by their shorter antennae and behavioral differences in perching habits.
Diogmites
Hanging Thieves
Diogmites is a genus of medium to large robber flies (17–48 mm) in the family Asilidae, commonly known as "Hanging Thieves" for their distinctive feeding posture. The genus contains 73–77 recognized species distributed mainly in the Neotropics, with some species extending into the Nearctic region. Adults are ambush predators that capture flying or perching insects and feed while suspended from vegetation by their front legs. The genus is characterized by relatively long legs, a flexible prosternum that facilitates the hanging posture, and often striking green or iridescent eye coloration in live specimens.
Diogmites angustipennis
prairie robber fly
Diogmites angustipennis, commonly known as the prairie robber fly, is a widespread species of robber fly in the family Asilidae. It was first described by Loew in 1866 and has been subject to taxonomic revision, with three former species now synonymized with it. The species is known to prey on other insects, including adult wasps. It occurs across the south-central and southwestern United States.
Diogmites bilobatus
Diogmites bilobatus is a robber fly species (Diptera: Asilidae) described by Barnes in 2010 from museum specimens. It closely resembles the widespread D. angustipennis and occurs in the south-central and southwestern United States and northern Mexico. As a member of the genus Diogmites, it belongs to a group commonly known as 'hanging thieves' for their distinctive prey-handling behavior.
Diogmites coloradensis
A species of robber fly in the family Asilidae, Diogmites coloradensis belongs to the genus Diogmites, commonly known as 'hanging thieves' for their distinctive predatory behavior. The species was described by James in 1933 and is classified within the subfamily Dasypogoninae. Like other members of this genus, it is presumed to be an aerial predator of other insects.
Diogmites contortus
Diogmites contortus is a species of robber fly in the family Asilidae, described by Bromley in 1936. It belongs to the subfamily Dasypogoninae and the genus Diogmites, commonly known as the 'hanging thieves' for their distinctive prey-handling behavior. Members of this genus are notable among robber flies for their habit of suspending themselves from vegetation while manipulating captured prey.
Diogmites esuriens
Short-striped Hanging Thief
Diogmites esuriens is a species of robber fly in the family Asilidae, commonly known as the Short-striped Hanging Thief. The genus Diogmites is notable for the distinctive 'hanging' behavior of its members, which often dangle from their front or middle legs while manipulating prey with the remaining legs. This species was described by Bromley in 1936 and belongs to the subfamily Dasypogoninae.
Diogmites fragilis
Diogmites fragilis is a species of robber fly in the family Asilidae, subfamily Dasypogoninae. It belongs to a genus commonly known as "hanging thieves" for their distinctive behavior of suspending from vegetation while manipulating prey. The species was described by Bromley in 1936. Like other members of Diogmites, it is presumed to be an aerial predator of other insects, though specific behavioral observations for this species are not documented in the provided sources.
Diogmites herennius
hanging thief robber fly
Diogmites herennius is a species of robber fly in the family Asilidae, commonly known as a 'hanging thief' for its distinctive habit of suspending from vegetation by its front legs while manipulating prey with the remaining legs. The species belongs to the subfamily Dasypogoninae and is one of approximately 26 species in the genus Diogmites, which occurs primarily in the New World tropics and subtropics. Members of this genus are characterized by their elongated bodies, long legs, and predatory behavior.
Diogmites misellus
Little Hanging Thief
Diogmites misellus is a species of robber fly in the family Asilidae, commonly known as the Little Hanging Thief. The genus Diogmites is notable for its distinctive hunting behavior: members are known as 'hanging thieves' due to their habit of suspending themselves from vegetation by their forelegs while manipulating prey with their remaining legs. This species was described by Loew in 1866.
Diogmites missouriensis
Diogmites missouriensis is a species of robber fly in the family Asilidae, first described by Bromley in 1951. Robber flies in this genus are known for their distinctive hanging behavior, often perching with their forelegs raised and body suspended from vegetation. The specific epithet missouriensis indicates a connection to the state of Missouri, though the exact geographic implications of this naming are not documented in available sources. As with other Asilidae, this species is presumed to be an active aerial predator.
Diogmites perplexus
Diogmites platypterus
Black Hanging Thief
Diogmites platypterus is a species of robber fly in the family Asilidae, commonly known as the Black Hanging Thief. Like other members of the genus Diogmites, it is known for its distinctive hunting behavior of swinging from its front or middle legs while manipulating prey with the remaining legs. The species is part of a diverse group of predatory flies that are important components of insect communities across North America.
Diogmites pritchardi
Pritchard's Hanging Thief
Diogmites pritchardi is a species of robber fly in the family Asilidae, described by Bromley in 1936. The genus Diogmites, commonly known as "hanging thieves," is recognized for the distinctive behavior of members swinging from their front or middle legs while manipulating prey with the remaining legs. As with other Diogmites species, D. pritchardi is presumed to be an aerial predator of other insects.
Diogmites properans
Diogmites properans is a species of robber fly in the family Asilidae, subfamily Dasypogoninae. The genus Diogmites comprises approximately 26 species distributed primarily in the Americas. Members of this genus are commonly known as "hanging thieves" due to their distinctive behavior of suspending from vegetation by their front legs while manipulating prey with the remaining legs.
Diogmites sallei
Diogmites sallei is a species of robber fly in the family Asilidae. Members of the genus Diogmites are known as "hanging thieves" for their distinctive behavior of swinging from their front or middle legs while manipulating prey with the remaining legs. The species was originally described as Dasypogon sallei by Bellardi in 1861. Robber flies in this genus are recognized for their large size and striking green eyes.
Diogmites salutans
Hanging Thief
Diogmites salutans is a species of robber fly in the family Asilidae, characterized by its distinctive 'hanging thief' behavior where it suspends itself by its front legs while manipulating prey with the remaining legs. The species was described by Bromley in 1936 and belongs to the subfamily Dasypogoninae. Like other members of the genus Diogmites, it is an aerial predator of other insects.
Diogmites ternatus
Diogmites ternatus is a species of robber fly in the family Asilidae, a group of predatory flies known for their aggressive hunting behavior and wasp-like appearance. The genus Diogmites includes species commonly referred to as 'hanging thieves' due to their characteristic behavior of suspending themselves from vegetation by their forelegs while feeding on captured prey. As with other members of the Dasypogoninae subfamily, D. ternatus likely exhibits the robust body form and strong predatory adaptations typical of this lineage.
Diogmites texanus
Diogmites texanus is a species of robber fly in the family Asilidae, described by Bromley in 1934. As a member of the genus Diogmites, it belongs to a group known for large size and striking appearance, often featuring vivid coloration or prominent green eyes. The species is poorly documented in available sources, with most information limited to taxonomic classification rather than detailed natural history.
Eccritosia zamon
Eccritosia zamon is a species of robber fly in the family Asilidae. It is noted among robber flies for its vivid, aposematic or mimetic coloration, placing it among the most visually striking species in this charismatic family of predatory flies. The species was originally described as Proctacanthus zamon by Townsend in 1895 before being transferred to the genus Eccritosia.
Echthodopa carolinensis
Echthodopa carolinensis is a species of robber fly (family Asilidae) described by Bromley in 1951. It belongs to a genus of predatory flies that capture prey in flight. The species epithet 'carolinensis' suggests a connection to the Carolinas region of the United States, though specific details about its biology and ecology remain poorly documented in available sources.
Echthodopa formosa
Echthodopa formosa is a species of robber fly in the family Asilidae, first described by Loew in 1872. Robber flies in this family are predatory insects known for their aggressive hunting behavior and diverse morphological adaptations. The genus Echthodopa is part of the diverse asilid fauna of North America. Available information about this specific species is limited beyond its taxonomic placement.
Efferia
Hammertails
Efferia is one of the most species-rich genera of robber flies (family Asilidae), comprising approximately 241 recognized species distributed primarily across the Neotropical and Nearctic regions. These medium to large predatory flies (10–40 mm) exhibit exceptional diversity in arid and semi-arid ecosystems of the New World, with particularly high abundance in desert and grassland habitats. The genus is distinguished by pronounced sexual dimorphism in abdominal morphology and is notable for the males' distinctive 'helicopter tail' genital structure.
Efferia aestuans
Northeastern Hammertail
Efferia aestuans is a species of robber fly (family Asilidae) native to eastern North America. It is one of the more commonly encountered members of the genus Efferia in its range. The species exhibits sexual dimorphism in body size, with females larger than males. Originally described by Linnaeus in 1763 as Asilus aestuans, it has undergone several taxonomic revisions before its current placement in Efferia.
Efferia albibarbis
Sand Hammertail
Efferia albibarbis is a species of robber fly in the family Asilidae, known as the Sand Hammertail. It belongs to the albibarbis-complex within the genus Efferia and is found in the Grand Canyon region of the southwestern United States. The species has been documented as a predator of tiger beetles, specifically Cicindela hirticollis and Habroscelimorpha dorsalis dorsalis.
Efferia antiochi
Efferia antiochi is a species of robber fly (family Asilidae) described by Wilcox in 1966. The genus Efferia comprises large, predatory flies in the subfamily Asilinae, characterized by their robust build, prominent compound eyes, and strong predatory behavior. Efferia antiochi is one of numerous species in this diverse genus, which is primarily distributed in arid and semi-arid regions of North America. Like other robber flies, adults are aerial predators that capture other insects in flight.
Efferia apache
Efferia apache is a species of robber fly in the family Asilidae, described by Wilcox in 1966. The genus Efferia comprises predatory flies known for their aggressive hunting behavior. Records indicate this species has been observed in western Texas, specifically in juniper chaparral habitat at Gold Mine Canyon in Val Verde County. Adults have been collected at mercury-vapor lights, suggesting nocturnal or crepuscular activity patterns. The species name "apache" likely references the Apache peoples or geographic regions of the southwestern United States.
Efferia argentifrons
Silver-faced Hammertail
Efferia argentifrons is a robber fly in the family Asilidae, first described by Hine in 1911. The species is characterized by its distinctive silvery facial markings, as indicated by its specific epithet ('argentifrons' = silver-faced). It belongs to a large genus of predatory flies known for their robust build and aggressive hunting behavior. Field observations of this species are sparse, with only three documented observations on iNaturalist, suggesting it may be uncommon or underreported.
Efferia argyrosoma
Efferia argyrosoma is a species of robber fly (family Asilidae) described by Hine in 1911. The genus Efferia represents one of the most diverse and widespread groups of robber flies in North America, with species typically characterized by their predatory behavior and distinctive male genitalia. As a member of the subfamily Asilinae, E. argyrosoma shares the general robust body form and predatory habits typical of this group. The specific epithet 'argyrosoma' refers to the silvery or argent body coloration characteristic of this species.
Efferia armata
Golden Club-legged Hammertail
Efferia armata is a species of robber fly in the family Asilidae, described by Hine in 1918. The species is known by the common name Golden Club-legged Hammertail. Like other members of the genus Efferia, it is a predatory dipteran that hunts other insects. The genus Efferia comprises a large group of robber flies distributed primarily in the Americas, with many species exhibiting distinctive morphological features and habitat preferences.
Efferia aurimystacea
Efferia aurimystacea is a species of robber fly in the family Asilidae, first described by Hine in 1919. The genus Efferia comprises large, predatory flies distributed primarily in North America, with many species exhibiting distinctive sexual dimorphism including swollen male genital capsules. This species belongs to a group historically associated with the genus Triorla, though modern taxonomy generally treats Efferia as valid. Robber flies in this genus are aerial predators that capture other insects in flight.