Spider-parasitoid
Guides
Acroceridae
small-headed flies, hunch-back flies, spider flies
Acroceridae are a small family of approximately 520 species in 50 genera, characterized by their distinctive hump-backed thorax and disproportionately small head. Adults are primarily nectar feeders with exceptionally long proboscises, while larvae are obligate endoparasitoids of spiders. Many species exhibit bee or wasp mimicry. The family is cosmopolitan but nowhere abundant, with most species known from fewer than 10 specimens.
Acrotaphus
Acrotaphus is a genus of spider-attacking parasitoid wasps in the family Ichneumonidae, subfamily Pimplinae, tribe Ephialtini. The genus contains 27 described species distributed across the New World, with particularly high diversity in the Neotropics including the Brazilian Amazon. These wasps are ectoparasitoids of orb-weaver spiders in the families Araneidae and Tetragnathidae. A defining characteristic of the genus is the ability to induce behavioral modification in host spiders, causing them to construct specialized "cocoon webs" that support and protect the wasp pupae.
Acrotaphus fuscipennis
Acrotaphus fuscipennis is a species of ichneumon wasp in the family Ichneumonidae, first described by Cresson in 1865. The genus Acrotaphus comprises parasitoid wasps that attack spiders. A. fuscipennis is one of approximately 8 species in the genus recorded from North America. Like other members of Acrotaphus, this species is presumed to be an ectoparasitoid of orb-weaving spiders (Araneidae), though specific host records for A. fuscipennis itself appear to be lacking in published literature.
Climaciella
wasp mantidflies
Climaciella is a genus of wasp mantidflies in the family Mantispidae, comprising approximately 10 described species distributed from North America through Central America to South America and parts of the Caribbean. Adults are notable for their striking Batesian mimicry of polistine paper wasps (Vespidae), featuring a constricted "wasp waist," wings folded longitudinally over the back rather than pitched roof-like, and darkened wing bases that simulate the longitudinal fold of vespid wings. The genus is best known from the common and widespread species C. brunnea, which has been extensively studied for its unique life history involving obligate spider egg-sac parasitism.
Clistopyga
Clistopyga is a genus of ichneumonid wasps in the subfamily Pimplinae, first described by Gravenhorst in 1829. The genus contains approximately 50 described species, with the majority distributed in the Neotropical region. Species are characterized by specialized adaptations for parasitizing spiders, including modified ovipositors used for clinging to hosts and felting spider silk to seal nest openings. Several species groups have been established within the genus based on morphological and distributional patterns.
Ephialtini
Ephialtini is a tribe of ichneumonid wasps within the subfamily Pimplinae, comprising approximately 17 genera and at least 120 species. Members are exclusively parasitoids of spiders (Araneae), with many species belonging to the 'Polysphincta group' that attack post-embryonic spiders. These wasps exhibit diverse host specificity patterns, ranging from polyphagy across multiple spider families to strict specialization on particular host species or genera. Some species parasitize adult spiders while others attack spider egg sacs.
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.
Gelis
Gelis is a genus of ichneumon wasps in the family Ichneumonidae, containing at least 270 described species. The genus is characterized by small, often wingless females that are parasitoids of various arthropod hosts. Some species have been documented attacking spiders, including ant-eating spiders in the genus Zodarion. The genus shows considerable diversity in form and life history across its species.
Mantispidae
mantidflies, mantispids, mantid lacewings, mantis-flies
Mantispidae is a family of neuropteran insects comprising approximately 400 species in around 400 genera, distributed worldwide with highest diversity in tropical and subtropical regions. Adults are predators characterized by raptorial forelegs—convergent with mantises but independently evolved—used to capture small arthropod prey. The family exhibits diverse larval life histories: Mantispinae are ectoparasitoids of spider egg sacs; Symphrasinae parasitize ground-nesting hymenopterans and scarab beetle larvae; Calomantispinae are predatory on small arthropods; and Drepanicinae life history remains largely unknown. First-instar larvae (planidia) employ specialized host-location strategies including direct penetration of egg sacs or phoretic transport on female spiders.
Neotypus nobilitator
Neotypus nobilitator is a species of ichneumonid wasp in the family Ichneumonidae. It belongs to a genus of parasitoid wasps whose members are primarily associated with spider hosts. The species has been recorded across northern Europe and North America. Like other ichneumonids, it likely develops as a koinobiont endoparasitoid, though specific biological details remain poorly documented.
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.
Oxyrrhexis
Oxyrrhexis is a genus of ichneumon wasps in the subfamily Pimplinae, tribe Ephialtini, belonging to the Polysphincta genus-group. The genus comprises four described species worldwide. All species are koinobiont ectoparasitoids specialized in attacking spiders, primarily of the family Theridiidae, though one record documents parasitism of a titanoecid spider. The genus was first recorded from Egypt in 2017.
Oxyrrhexis carbonator
Oxyrrhexis carbonator is a species of ichneumon wasp in the family Ichneumonidae, first described by Gravenhorst in 1807. It belongs to the Polysphincta genus-group within the subfamily Pimplinae, tribe Ephialtini. The species is a koinobiont parasitoid of spiders, with documented host associations across multiple spider families including Theridiidae and Titanoecidae.
Phalacrotophora epeirae
Phalacrotophora epeirae is a species of scuttle fly in the family Phoridae, originally described by Brues in 1902 under the name Phora epeirae. The genus Phalacrotophora is known for species that are parasitoids of spiders, though the specific host relationships of P. epeirae have not been documented in detail. This species belongs to a group of small, humpbacked flies characterized by their distinctive running behavior and reduced wing venation.
Schizopyga
Schizopyga is a genus of pimpline ichneumonid wasps in the Polysphincta genus-group, comprising approximately 12 described species worldwide. These wasps are specialized parasitoids of spiders that construct non-aerial webs, particularly members of the families Clubionidae, Gnaphosidae, and Agelenidae. The genus was established by Gravenhorst in 1829 and has a cosmopolitan distribution with records from multiple biogeographic regions including the Afrotropical region.
Zatypota
Zatypota is a genus of ichneumonid wasps comprising at least 40 described species, distributed across Europe, Asia, and the Americas. All species are koinobiont ectoparasitoids of spiders, primarily targeting theridiid spiders though some species parasitize linyphiids and araneids. The genus is notable for inducing behavioral manipulation in host spiders, causing them to construct specialized "cocoon webs" that protect the developing wasp larva. Several species have been documented as hosts for hyperparasitoid chalcidid wasps, forming complex three-trophic-level interactions.