Robber-fly
Guides
Efferia azteci
Efferia azteci is a species of robber fly in the family Asilidae, described by Wilcox in 1966. The genus Efferia belongs to a group of large, predatory flies commonly known as robber flies, which are characterized by their stout bodies, prominent compound eyes, and predatory behavior. This species is part of a diverse assemblage of Asilidae found in North America, with members of the genus often exhibiting distinctive sexual dimorphism in abdominal coloration patterns.
Efferia basini
Efferia basini is a species of robber fly (family Asilidae) described by Wilcox in 1966. As a member of the genus Efferia, it belongs to a diverse group of predatory flies found primarily in the Americas. Robber flies in this genus are known for their robust build, strong predatory capabilities, and distinctive morphological features. The specific epithet 'basini' honors an individual, following common practice in entomological nomenclature.
Efferia beameri
Efferia beameri is a species of robber fly in the family Asilidae, described by Wilcox in 1966. As a member of the large genus Efferia, this species belongs to a diverse group of predatory flies found primarily in the Americas. The genus Efferia is one of the most species-rich genera of Asilidae, with many species exhibiting distinctive morphological features and ecological specializations. Specific details regarding the biology and distribution of E. beameri remain poorly documented in published literature.
Efferia belfragei
Efferia belfragei is a species of robber fly (family Asilidae) described by Hine in 1919. The genus Efferia comprises large, predatory flies that are among the most charismatic members of the family. Species in this group are characterized by their robust build, prominent mystax (beard of bristles), and predatory behavior. Efferia belfragei belongs to a genus that was historically treated broadly but has undergone significant taxonomic revision, with some former subgenera now recognized as distinct genera such as Triorla. The species is part of a diverse assemblage of robber flies in North America, particularly well-represented in the southwestern United States and Mexico.
Efferia bexarensis
Efferia bexarensis is a species of robber fly (family Asilidae) described by Bromley in 1934. The specific epithet 'bexarensis' indicates its type locality in Bexar County, Texas. As a member of the Efferia group of robber flies, it belongs to a diverse and widespread lineage of predatory dipterans known for their robust build and aggressive hunting behavior. The species is documented from Texas, though detailed biological information remains limited in published literature.
Efferia bicaudata
Great Plains Hammertail
Efferia bicaudata is a species of robber fly in the family Asilidae, commonly known as the Great Plains Hammertail. The species was originally described as Erax bicaudatus by Hine in 1919 and later transferred to the genus Efferia. A 1964 study in the Annals of the Entomological Society of America examined its distribution, ethology, and egg morphology, representing one of the few detailed biological studies of this species. As a member of the Asilidae, it is a predatory fly that captures other insects in flight.
Efferia bicolor
Lesser Mesquite Hammertail
Efferia bicolor is a species of robber fly in the family Asilidae, commonly known as the Lesser Mesquite Hammertail. It belongs to the genus Efferia, a large group of predatory flies found primarily in the Americas. The species was first described by Bellardi in 1861. Like other robber flies, it is an aerial predator that captures other insects in flight.
Efferia bryanti
Madera Canyon Hammertail
Efferia bryanti is a species of robber fly in the family Asilidae, described by Wilcox in 1966. It is commonly known as the Madera Canyon Hammertail. The species belongs to the large and diverse genus Efferia, which contains numerous North American robber fly species. As with other Efferia species, E. bryanti is a predatory fly that likely hunts other insects.
Efferia cabeza
Efferia cabeza is a species of robber fly in the family Asilidae, described by Wilcox in 1966. The genus Efferia belongs to a group of large, predatory flies commonly known as robber flies, which are characterized by their robust build, large eyes, and predatory behavior. Members of this genus are primarily distributed in the Americas. The species epithet "cabeza" (Spanish for "head") may allude to distinctive head morphology, though specific diagnostic features for this species remain poorly documented in accessible literature.
Efferia caliente
Caliente Hammertail
Efferia caliente is a species of robber fly in the family Asilidae, described by Wilcox in 1966. The common name "Caliente Hammertail" references the Caliente Range in California, where the species was presumably first collected or is known to occur. Robber flies in the genus Efferia are predatory insects known for their robust build and predatory habits. As with other Asilidae, adults are aerial predators that capture other insects in flight.
Efferia cana
Efferia cana is a species of robber fly in the family Asilidae, described by Hine in 1916. The genus Efferia belongs to a group of large, predatory flies commonly known as robber flies or assassin flies. Members of this genus are characterized by their robust build, prominent compound eyes, and predatory behavior. Efferia cana is part of a diverse assemblage of Asilidae species found in North America, where these flies occupy important roles as aerial predators in various terrestrial habitats.
Efferia candida
Efferia candida is a species of robber fly in the family Asilidae, first described by Coquillett in 1893. As a member of the genus Efferia, it belongs to one of the most species-rich genera of robber flies in North America. Robber flies in this genus are characterized by their robust build, large compound eyes, and predatory behavior. The species name "candida" (Latin for "white" or "shining") likely refers to some aspect of its pale or light-colored appearance, though specific diagnostic features distinguishing it from congeners require detailed examination.
Efferia canella
Sierritas Hammertail
Efferia canella is a species of robber fly in the family Asilidae, commonly known as the Sierritas Hammertail. It belongs to the large and diverse genus Efferia, which contains numerous species distributed primarily across North and South America. Robber flies in this genus are predatory insects known for their robust build and agile flight capabilities. The specific epithet "canella" and common name "Sierritas Hammertail" suggest an association with the Sierritas Mountains region, though detailed ecological information for this particular species remains limited.
Efferia clementei
Efferia clementei is a species of robber fly (family Asilidae) described by Wilcox and Martin in 1945. The species belongs to the large genus Efferia, a group of predatory flies distributed primarily across the Americas. As with other robber flies, E. clementei is presumed to be an aerial predator of other insects, though specific ecological details remain poorly documented in published literature.
Efferia completa
Rio Grande Hammertail
Efferia completa is a species of robber fly (family Asilidae) known by the common name Rio Grande Hammertail. It belongs to the large and diverse genus Efferia, which comprises predatory flies distributed primarily in the Americas. The species was described by Macquart in 1838. Like other asilids, it is presumed to be an aerial predator of other insects.
Efferia coquillettii
Efferia coquillettii is a species of robber fly (family Asilidae) first described by Hine in 1919. The genus Efferia comprises medium to large-sized predatory flies found primarily in arid and semi-arid regions of North America. Members of this genus are characterized by their robust build, prominent mystax (facial bristles), and predatory behavior. Efferia species are often encountered at light traps and are active predators of other insects.
Efferia costalis
Crested Hammertail
Efferia costalis is a species of robber fly (Asilidae) described by Williston in 1885. The species is known by the common name "Crested Hammertail." As a member of the genus Efferia, it belongs to a diverse group of predatory flies commonly found in North America. The species has been documented through limited observations, with only 3 records reported on iNaturalist.
Efferia coulei
Northwestern Hammertail
Efferia coulei is a robber fly (family Asilidae) described by Wilcox in 1966. It occurs in the grasslands of southern British Columbia, Canada, particularly the Okanagan Valley, where it is sympatric with its closest relative Efferia okanagana. The two species are genetically distinct, with approximately 7.0% divergence in cytochrome oxidase I (COI) DNA barcode sequences. As a member of the Efferia arida species group, it shares morphological affinities with E. arida and E. pinali.
Efferia cressoni
Efferia cressoni is a species of robber fly in the family Asilidae, originally described by Hine in 1919. The species belongs to a large and diverse genus of predatory flies found primarily in the Americas. Robber flies in the genus Efferia are known for their robust build, strong flying ability, and predatory behavior. The specific epithet honors Cresson, likely referring to the entomologist Ezra Townsend Cresson.
Efferia cuervana
Red-legged Hammertail
Efferia cuervana is a species of robber fly in the family Asilidae, first described by Hardy in 1943. It belongs to the large genus Efferia, which contains numerous species distributed primarily in the Americas. Robber flies in this genus are predatory insects known for their robust build, large compound eyes, and characteristic perching behavior while hunting. The common name 'Red-legged Hammertail' refers to distinctive morphological features of this species.
Efferia davisi
Davis Hammertail
Efferia davisi is a species of robber fly in the family Asilidae, first described by Wilcox in 1966. It belongs to a large genus of predatory flies commonly known as 'hammertails' due to the swollen male genital capsule. The species is part of the diverse Nearctic fauna of Efferia, which contains numerous species distributed across North America. Like other robber flies, E. davisi is an aerial predator that captures other insects in flight.
Efferia duncani
Efferia duncani is a species of robber fly in the family Asilidae, first described by Wilcox in 1966. The genus Efferia comprises large, predatory flies that are morphologically similar to the related genus Triorla. Robber flies in this group are characterized by their robust build, large eyes, and predatory behavior. Specific ecological details for E. duncani remain poorly documented in the available literature.
Efferia femorata
Pine-trunk Hammertail
A species of robber fly in the family Asilidae, commonly known as the Pine-trunk Hammertail. The species was described by Macquart in 1838 and belongs to the diverse genus Efferia, which contains numerous similar-looking species that are often difficult to distinguish without careful examination.
Efferia frewingi
Columbia River Hammertail
Efferia frewingi is a species of robber fly (family Asilidae) described by Wilcox in 1966. Based on the genus Efferia, it belongs to a diverse group of predatory flies known for their robust bodies, large eyes, and aerial hunting behavior. The species epithet "frewingi" honors an individual, following the patronymic naming convention common in entomology. The common name "Columbia River Hammertail" suggests an association with the Columbia River region, though specific ecological details remain poorly documented in accessible literature.
Efferia gila
Efferia gila is a species of robber fly in the family Asilidae, described by Wilcox in 1966. The genus Efferia comprises predatory flies commonly known as robber flies, characterized by their stout bodies, large eyes, and predatory behavior. This species is part of a diverse genus distributed primarily in the Americas.
Efferia grandis
Great Mesquite Hammertail
Efferia grandis is a species of robber fly (family Asilidae) described by Hine in 1919. It belongs to the diverse genus Efferia, which contains many species of predatory flies found primarily in North America. The common name "Great Mesquite Hammertail" suggests an association with mesquite habitats, though specific ecological details remain limited in available sources.
Efferia harveyi
Harvey Hammertail
Efferia harveyi is a species of assassin fly (family Asilidae), commonly known as the Harvey Hammertail. Originally described as Erax harveyi by Hine in 1919, it was later transferred to the genus Efferia. Like other members of the Asilidae, this species is a predatory fly. The common name 'Harvey Hammertail' refers to the clubbed or expanded abdomen tip characteristic of many Efferia species. The species has been documented in at least 25 observations on iNaturalist.
Efferia helenae
Helen Hammertail
Efferia helenae is a species of robber fly in the family Asilidae, first described by Bromley in 1951. The species is known from limited observations, with only 14 documented occurrences on iNaturalist. Like other members of the genus Efferia, it is presumed to be a predatory fly that hunts other insects. The common name "Helen Hammertail" refers to the characteristic swollen genital capsule of males in this genus.
Efferia kansensis
Efferia kansensis is a species of robber fly in the family Asilidae, described by Hine in 1919. The specific epithet "kansensis" indicates Kansas as the type locality. As a member of the genus Efferia, it belongs to a group of medium to large-sized robber flies that are characteristic of North American arid and semi-arid regions. The genus Efferia is taxonomically complex and has undergone significant revision, with some former segregates now recognized as valid genera.
Efferia kondratieffi
Kondratieff Hammertail
Efferia kondratieffi is a species of robber fly in the family Asilidae, described by Bullington & Lavigne in 1984. It belongs to the large genus Efferia, which comprises numerous species across North and South America. The species was formally described with comparative notes on the related Efferia aestuans. Like other robber flies, it is a predatory insect with a characteristic robust build and strong flying ability.
Efferia latruncula
Efferia latruncula is a species of robber fly in the family Asilidae, first described by Williston in 1885. It belongs to the large genus Efferia, which contains numerous species distributed primarily in arid and semi-arid regions of North and South America. Like other robber flies, it is a predatory insect that captures other arthropods in flight. The specific epithet 'latruncula' is Latin for 'little robber' or 'brigand,' reflecting the predatory habits characteristic of the family.
Efferia leucocoma
Efferia leucocoma is a species of robber fly in the family Asilidae. Robber flies are predatory insects known for their aggressive hunting behavior, capturing other insects in flight. Members of the genus Efferia are generally robust, medium to large-sized flies with characteristic morphological features including a well-developed mystax (beard of bristles on the face). The specific epithet 'leucocoma' refers to white hair-like structures, likely describing some aspect of the species' pubescence or coloration.
Efferia mesquite
Mesquite robber fly
Efferia mesquite is a species of robber fly in the family Asilidae, described by Bromley in 1951. The species epithet "mesquite" suggests an association with mesquite trees (Prosopis spp.), which serve as perching and hunting substrates for adults. Like other Efferia species, it is a predatory fly that captures other insects in flight. The genus Efferia is part of a complex of robber flies formerly grouped under Efferia but now split into several genera including Efferia sensu stricto and Triorla.
Efferia monki
Efferia monki is a species of robber fly in the family Asilidae, described by Bromley in 1951. Like other members of the genus Efferia, it belongs to a diverse group of predatory flies characterized by their stout bodies, large compound eyes, and raptorial legs adapted for capturing prey in flight. The species name honors an individual with the surname Monk, though the specific etymology is not detailed in available sources. As with most Efferia species, detailed biological information remains limited in published literature.
Efferia mortensoni
Portal Hammertail
Efferia mortensoni is a species of robber fly in the family Asilidae, described by Wilcox in 1966. It is known by the common name "Portal Hammertail." Like other members of the genus Efferia, this species is a predatory dipteran that likely hunts other insects. The species name suggests a connection to the Portal area in southeastern Arizona, a region well-known among entomologists for its exceptional biodiversity. Robber flies in this genus are typically active during daylight hours and are often observed perching on vegetation or the ground while hunting.
Efferia nemoralis
Woodland Hammertail
Efferia nemoralis is a species of robber fly in the family Asilidae, commonly known as the Woodland Hammertail. It is one of approximately 80 species in the genus Efferia, which is distributed primarily in the Americas. The species was originally described as Erax nemoralis by Hine in 1911 and later transferred to Efferia. Like other robber flies, it is a predatory insect that captures prey in flight.
Efferia neoinflata
Efferia neoinflata is a species of robber fly (family Asilidae) described by Wilcox in 1966. It belongs to a diverse genus of predatory flies distributed primarily in the Americas. The species epithet "neoinflata" suggests a relationship to or distinction from E. inflata, a pattern common in Efferia species nomenclature. As with other robber flies, adults are aerial predators that capture other insects in flight. The genus Efferia was historically treated as a subgenus within a broader concept of Asilus but has been elevated to full generic status in modern classifications.
Efferia okanagana
Okanagan Hammertail
Efferia okanagana is a species of robber fly (family Asilidae) described in 2012 from the grasslands of southern British Columbia, Canada. It belongs to the E. arida species group and is most closely related to E. arida and E. pinali. The species has a restricted distribution centered on the Okanagan Valley and is considered potentially at risk by COSEWIC.
Efferia ordwayae
Efferia ordwayae is a species of robber fly (family Asilidae) described by Wilcox in 1966. Like other members of the genus Efferia, it is a predatory dipteran characterized by a robust body, strong legs adapted for seizing prey, and a prominent mystax of bristles on the face. The genus Efferia is one of the largest genera of robber flies in North America, with species typically associated with open, dry habitats. Specific information about the biology and distribution of E. ordwayae remains limited in the available literature.
Efferia pallidula
Efferia pallidula is a species of robber fly in the family Asilidae, described by Hine in 1911. As a member of the large and diverse genus Efferia, it shares the characteristic predatory habits and robust morphology typical of this group. The specific epithet "pallidula" suggests pale coloration relative to congeners. Detailed natural history information for this particular species appears limited in the available literature.
Efferia peralta
Efferia peralta is a species of robber fly (family Asilidae) described by Wilcox in 1966. The genus Efferia belongs to the subfamily Asilinae, a group of large, predatory flies characterized by powerful flight and strong raptorial legs adapted for capturing other insects in flight. Species in this genus are primarily distributed in the Americas, with many occurring in arid and semi-arid regions. E. peralta is among the many Asilidae species whose biology remains poorly documented in the scientific literature.
Efferia pernicis
Efferia pernicis is a species of robber fly in the family Asilidae, described by Coquillett in 1893. As a member of the genus Efferia, it belongs to a diverse group of predatory flies characterized by their robust build, large eyes, and raptorial legs adapted for capturing prey in flight. The species is part of the Asilinae subfamily, which contains many of the larger and more conspicuous robber flies in North America.
Efferia pinali
Efferia pinali is a species of robber fly (family Asilidae) described by Wilcox in 1966. As a member of the genus Efferia, it belongs to a diverse group of predatory flies found primarily in the Americas. The specific epithet "pinali" suggests an association with pine habitats or the Pinal region, though explicit habitat documentation for this particular species is limited. Robber flies in this genus are generally medium to large-sized predators that hunt other insects in flight.
Efferia pogonias
Yellow-bearded Hammertail
Efferia pogonias is a species of robber fly in the family Asilidae, commonly known as the yellow-bearded hammertail. It is endemic to the eastern United States, where it occurs from Maine to Georgia and westward to Minnesota and Texas. The species prefers open, dry habitats including sandy inland locations. Adults are active from May to October with peak activity in September and October. Females oviposit in soil.
Efferia prairiensis
Prairie Hammertail
Efferia prairiensis is a species of robber fly in the family Asilidae, commonly known as the Prairie Hammertail. It belongs to the large and diverse genus Efferia, which contains many North American species. Robber flies in this genus are predatory insects that typically hunt other insects in flight. The specific epithet "prairiensis" suggests an association with prairie habitats.
Efferia prattii
Laredo Hammertail
Efferia prattii is a species of robber fly in the family Asilidae, originally described by Hine in 1919. The species is known from the southern United States, particularly Texas, and is referred to by the common name "Laredo Hammertail." As a member of the genus Efferia, it belongs to a group of large, predatory flies that are active hunters of other insects. The species has been documented in entomological surveys in western Texas, where it was observed at mercury-vapor lights in juniper chaparral habitat alongside other asilid species.
Efferia producta
White Thorny Hammertail
Efferia producta is a robber fly species in the family Asilidae, described by Hine in 1919. The common name "White Thorny Hammertail" refers to distinctive features of this species. As with other Efferia species, it belongs to a diverse genus of predatory flies known for their robust build and predatory habits. The species has been documented through limited observations on iNaturalist, suggesting it may be relatively uncommon or underreported. Robber flies in this genus are typically associated with arid and semi-arid habitats in western North America.
Efferia rapax
Yellow-haired Hammertail
Efferia rapax is a species of robber fly in the family Asilidae, commonly known as the Yellow-haired Hammertail. Robber flies in this genus are predatory insects known for their aggressive hunting behavior, capturing other insects in flight. The species is part of a large and diverse genus of medium to large-sized robber flies distributed primarily in the New World. Specific biological details for E. rapax are limited in published literature.
Efferia slossonae
Scrub Hammertail
Efferia slossonae is a species of robber fly (family Asilidae) described by Hine in 1919. It belongs to the diverse genus Efferia, a group of predatory flies distributed primarily in the Americas. The species has been documented in the southwestern United States, with observations concentrated in Texas and surrounding regions. Like other robber flies, it is an aerial predator that captures other insects in flight.
Efferia spiniventris
Efferia spiniventris is a species of robber fly (family Asilidae) described by Hine in 1919. The species belongs to the large and diverse genus Efferia, which is primarily distributed in the New World. Robber flies in this genus are predatory as adults, typically hunting other insects. The specific epithet "spiniventris" refers to spiny ventral characteristics. The genus Efferia has undergone taxonomic revision, with some former subgenera now recognized as distinct genera such as Triorla.