Anasimyia perfidiosus
(Hunter, 1897)
Treacherous Swamp Fly
Anasimyia perfidiosus is a of hoverfly ( Syrphidae) found in North America. It was originally described in the Lejops and is still sometimes referenced by that synonym. The species is known by the Treacherous Swamp Fly. It belongs to the Eristalinae, a group of syrphid flies often associated with aquatic or semi-aquatic .
Pronunciation
How to pronounce Anasimyia perfidiosus: /ˈænəˌsaɪmiːə pɜːˈfɪdioʊsəs/
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Identification
May be distinguished from other Anasimyia by subtle morphological features of the and abdominal patterning, though specific diagnostic characters require examination of . The former placement in Lejops reflects historical taxonomic confusion within the Helophilina subtribe. Accurate identification to species level typically requires microscopic examination of male genitalia or detailed comparison with verified specimens.
Images
Habitat
As a member of the subtribe Helophilina, likely associated with marshy or wetland environments where larvae develop in decaying organic matter or aquatic vegetation.
Distribution
North America. Specific range details beyond continental distribution are not documented in available sources.
Life Cycle
As with other members of Eristalinae, development includes , larval, pupal, and stages. Larvae of related Anasimyia are known to inhabit aquatic or semi-aquatic environments, often in decaying plant matter.
Ecological Role
likely serve as . Larval is presumed similar to related , potentially contributing to decomposition in wetland .
Similar Taxa
- Anasimyia bilinearisOverlapping North American range and similar overall ; requires careful examination of facial structure and abdominal coloration for separation.
- Lejops species (historical grouping)Formerly classified together; A. perfidiosus was transferred from Lejops based on phylogenetic and morphological studies, but older literature may use the outdated combination.
More Details
Taxonomic History
Originally described as Lejops perfidiosus by Hunter in 1897. Transferred to Anasimyia following revision of the Helophilina subtribe. The specific epithet 'perfidiosus' (Latin: treacherous, deceitful) inspired the 'Treacherous Swamp Fly'.
Data Deficiency
Only 7 observations recorded on iNaturalist as of source date, indicating this is rarely encountered or underreported. No published studies specifically addressing its or were found in provided sources.