Acroceridae
Guides
Acrocera bakeri
Acrocera bakeri is a species of small-headed fly in the family Acroceridae, described by Coquillett in 1904. Species in this genus are endoparasitoids of spiders. The larvae seek out and enter spider hosts, feeding internally until mature, then exit to pupate. Acrocera is one of the most species-rich genera in Acroceridae in North America.
Acrocera obsoleta
Acrocera obsoleta is a species of small-headed fly in the family Acroceridae, a group of Diptera characterized by their notably reduced head size and distinctive humpbacked appearance. The species was described by Wulp in 1867. Like other members of the family, it is likely parasitoid in its larval stage, though specific host records for this species remain undocumented. The genus Acrocera is one of the more speciose genera within this small, morphologically unusual family.
Acrocera subfasciata
Acrocera subfasciata is a species of small-headed fly in the family Acroceridae, first described by Westwood in 1848. The species is currently accepted as valid by GBIF, though Catalogue of Life lists it as a synonym. Like other members of its genus, it is an endoparasitoid of spiders. The species is known from the United States, with limited observational records.
Eulonchus marginatus
jewelled spider fly
Eulonchus marginatus is a species of small-headed fly in the family Acroceridae, commonly known as a jewelled spider fly. The species has a Nearctic distribution and is known to visit flowers from over ten different plant families. Like other members of the genus, adults exhibit metallic coloration and serve as pollinators, while larvae are parasitoids of spiders.
Eulonchus sapphirinus
Sapphire spider fly
Eulonchus sapphirinus is a species of small-headed fly in the family Acroceridae, commonly known as the sapphire spider fly. Adults are metallic blue in coloration and are specialized flower visitors, particularly abundant on Geranium robertianum in Olympic National Park, Washington. The species exhibits sexually dimorphic flower-visiting behavior related to mating, with females moving more slowly among flowers than males. Like other members of its genus, the larvae are parasitoids of spiders, though specific host records for this species remain unconfirmed.
Eulonchus tristis
small-headed fly
Eulonchus tristis is a small-headed fly (family Acroceridae) native to western North America. Adults are known flower visitors, particularly of Brodiaea elegans and Iris douglasiana in California, where they carry substantial pollen loads. The species has been documented as a potential pollinator, especially for B. elegans. Like other acrocerids, larvae are parasitoids of spiders.
Ocnaea boharti
Ocnaea boharti is a species of small-headed fly in the family Acroceridae, described by Schlinger in 1983. The species epithet honors Richard M. Bohart (1913–2007), a prominent UC Davis entomologist who researched Strepsiptera and for whom the Bohart Museum of Entomology is named. Members of the genus Ocnaea are known as endoparasitoids of spiders, with larvae entering host bodies and consuming them from within. This species belongs to the subfamily Panopinae, one of several lineages within this morphologically unusual family of Diptera.
Ocnaea sequoia
Ocnaea sequoia is a species of small-headed fly in the family Acroceridae, described by Sabrosky in 1948. Small-headed flies are a distinctive group of Diptera characterized by their unusual head morphology and parasitic life history. The specific epithet 'sequoia' suggests a possible association with giant sequoia (Sequoiadendron giganteum) forests, though this relationship has not been explicitly documented in available sources.
Ogcodes canadensis
Ogcodes canadensis is a species of small-headed flies in the family Acroceridae, described by Schlinger in 1960. Members of this family are characterized by their distinctive small heads and humpbacked appearance. The species is currently accepted as valid, though it has been listed as a synonym in some sources.
Ogcodes dispar
Ogcodes dispar is a species of small-headed fly in the family Acroceridae, first described by Macquart in 1855. The species is characterized by the distinctive morphology typical of the genus, including a small head and humpbacked thorax. It belongs to a family whose larvae are known to be internal parasitoids of spiders, though specific host associations for this species remain poorly documented. Available observations are limited, with only 12 records documented on iNaturalist.
Ogcodes eugonatus
small-headed fly
Ogcodes eugonatus is a species of small-headed flies in the family Acroceridae. The larvae are parasitoids of spiders, with documented hosts in five families: Lycosidae, Oxyopidae, Thomisidae, Salticidae, and Agelenidae. Adult morphology is characteristic of the genus Ogcodes, with a small head and rounded body form typical of Acroceridae.
Ogcodes pallidipennis
A species of small-headed fly in the family Acroceridae. Larvae are parasitic, developing within the wolf spider *Pardosa lapidicina*.
Pterodontia
small-headed flies
Pterodontia is a genus of small-headed flies in the family Acroceridae, first described by Gray in 1832. The genus contains at least 20 described species. Members of this genus are characterized by distinctive morphological features including hairy eyes and reduced mouthparts. Like other acrocerids, they are likely parasitoids with specialized life histories, though detailed biological data remain limited for most species.
Pterodontia flavipes
small-headed fly
Pterodontia flavipes is a species of small-headed fly in the family Acroceridae. Adult males measure 5.5–10.5 mm, while females are 5–9 mm. The species exhibits complete metamorphosis with larval development occurring in soil. Adults have been observed in grassy areas and are known for rapid, hovering flight.
Pterodontia westwoodi
Pterodontia westwoodi is a species of small-headed fly in the family Acroceridae, described by Sabrosky in 1948. Members of this family are characterized by their distinctive humpbacked appearance and reduced head size. The genus Pterodontia is part of the subfamily Panopinae. Information regarding the specific biology and ecology of P. westwoodi remains limited, with only six observations recorded in iNaturalist.
Turbopsebius
Turbopsebius is a genus of small-headed flies (family Acroceridae) comprising approximately four described species. The genus was established by Schlinger in 1972 and belongs to the subfamily Cyrtinae. Species within this genus exhibit the characteristic reduced head morphology typical of Acroceridae, with adults bearing a small, globular head on a narrow neck.
Turbopsebius diligens
small-headed fly
Turbopsebius diligens is a species of small-headed fly in the family Acroceridae, described by Osten Sacken in 1877. It was originally placed in the genus Opsebius before being transferred to Turbopsebius. Small-headed flies are a distinctive group of Diptera characterized by their unusual head morphology and parasitoid life history. The species has been documented through limited observations, with approximately 20 records on iNaturalist.