# Deinopidae
**Deinopidae** is a family of spiders known as net-casting spiders or ogre-faced spiders, named for their hunting method: they hold a small, square net of wool-like silk in their front legs and stretch it wide to envelop passing insect prey[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/). The family belongs to the order Araneae, class Arachnida[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/), and its members are recognizable by a stick-like body, spindly legs, and, in the genus *Deinopis*, a pair of enormously enlarged posterior median eyes that give the "ogre-faced" appearance[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/) • [2](https://www.si.edu/object/systematics-spider-family-deinopidae-revision-genus-menneus-jonathan-coddington-matjaz-kuntner-and%3Asiris_sil_988848).
| Key fact | Detail |
|---|---|
| Scientific name | Deinopidae C. L. Koch, 1850; common names ogrefaced spiders, net-casting spiders[3](https://www.itis.gov/servlet/SingleRpt/SingleRpt?anchorLocation=SubordinateTaxa&credibilitySort=TWG+standards+met&print_version=SCR&rankName=Species&search_topic=TSN&search_value=847716&source=from_print) |
| Accepted genera | Three extant genera: *Asianopis* Lin & Li, 2020 (37 species), *Deinopis* MacLeay, 1839 (20 species), and *Menneus* Simon, 1877 (14 species)[4](https://wsc.nmbe.ch/gen-list/25/Deinopidae) |
| Defining eyes | *Deinopis* is diagnosed by the extreme size of its posterior median eyes; *Menneus* has normally sized eyes[2](https://www.si.edu/object/systematics-spider-family-deinopidae-revision-genus-menneus-jonathan-coddington-matjaz-kuntner-and%3Asiris_sil_988848) |
| Hunting method | A small cribellate net held by the front legs is stretched wide to envelop passing prey; strikes are also made at flying insects[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/) |
| Size and habits | Body length 1.5–2.5 cm; arboreal; feeds on ants, beetles, crickets, and other spiders[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/) |
| Danger to humans | Not considered dangerous[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/) |
## Appearance and classification
The family was established by C. L. Koch in 1850, and the first deinopid genus was described by MacLeay in 1839, based on *Deinopis lamia* from Cuba[5](https://pmc.ncbi.nlm.nih.gov/articles/PMC7031397/). A 2012 monograph by Jonathan A. Coddington of the [Smithsonian Institution](https://www.edgepedia.org/smithsonian-institution), Matjaž Kuntner of the [Slovenian Academy of Sciences and Arts](https://www.edgepedia.org/slovenian-academy-of-sciences-and-arts), and Brent D. Opell of Virginia Polytechnic Institute and State University provided the first phylogeny of the family, based on 53 morphological and 3 behavioral characters scored for 17 deinopid species and 2 outgroups, and tested the monophyly of the family and its genera[2](https://www.si.edu/object/systematics-spider-family-deinopidae-revision-genus-menneus-jonathan-coddington-matjaz-kuntner-and%3Asiris_sil_988848).
Two genera dominate the classification. *Deinopis* is the larger, pantropical genus, diagnosed by the extreme size of its posterior median eyes, while *Menneus* is the smaller [Old World](https://www.edgepedia.org/old-world) (sub)tropical genus with normally sized eyes[2](https://www.si.edu/object/systematics-spider-family-deinopidae-revision-genus-menneus-jonathan-coddington-matjaz-kuntner-and%3Asiris_sil_988848). The World Spider Catalog currently accepts three genera, adding *Asianopis*, established in 2020 for Asian and Australian species formerly placed in *Deinopis*[4](https://wsc.nmbe.ch/gen-list/25/Deinopidae). Two former genera, *Avella* and *Avellopsis*, are now synonyms of *Menneus*[4](https://wsc.nmbe.ch/gen-list/25/Deinopidae).
[Australian Museum](https://www.edgepedia.org/australian-museum) identification notes describe net-casting spiders as having stick-like bodies with spindly legs. Members of *Asianopis* have a large, prominent pair of eyes at the front of the head and vary in color from fawn to pinkish brown or chocolate brown; *Menneus* species have smaller eyes and subtle greenish brown to gray patterning. Males are smaller and more slender than females and can differ in color and patterning[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/).
## Hunting behavior
Net-casting spiders are primarily nocturnal, feeding on ants, beetles, crickets, and other spiders[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/). At rest, the spider hangs head-downward from vegetation with its legs held together on each side, giving a stick-like appearance. While lying in wait for prey, the spider grips the net using its four front legs, hanging from strands attached to nearby vegetation by means of its rear legs and spinnerets.[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/)
The net is a bluish-white square of wool-like cribellate silk whose coiled lines are designed to stretch and entangle prey. To aim, the spider often drops splashes of white fecal droppings onto the leaf or bark beneath it, forming a target; when an insect walks across this target, the spider plunges the net downward to envelop it. A successful strike is followed by silk-wrapping, a paralyzing bite, and feeding. Unused nets may be hung on nearby leaves for the next night's hunting, or eaten[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/).
## Vision
The family is notable among web-building spiders for relying on vision rather than the vibrational cues that most web builders use. Field and laboratory occlusion experiments on *Deinopis spinosa* tested whether the enlarged posterior median eyes increase visually based nocturnal foraging efficiency[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC4892245/). According to [University of Cincinnati](https://www.edgepedia.org/university-of-cincinnati) visual ecologist Elke Buschbeck's survey of [spider vision](https://www.edgepedia.org/spider-vision), net-casting spiders in the genus *Deinopis* are the standout low-light foragers among spiders[7](https://homepages.uc.edu/~morehonn/wp-content/uploads/2021/02/Morehouse-NI-2020-Curr-Biol.pdf). An educational factsheet from the [University of Florida](https://www.edgepedia.org/university-of-florida) reports that *Deinopis* spiders absorb about 2,000 times more light than is needed for the comparison baseline it uses, an adaptation supporting net-casting in darkness[8](https://edis.ifas.ufl.edu/publication/IN1356/pdf).
Sensory plasticity has also been documented: in *D. spinosa*, the diameter of the posterior median eyes decreases between the penultimate and mature male stages, a pattern also reported in the Australian *D. subrufa*[9](https://pmc.ncbi.nlm.nih.gov/articles/PMC5399460/).
## Silk and evolution
Deinopids are among the "primitive" aerial web spinners of the superfamily Deinopoidea. A comparative study of silk reflectance found that these primitive aerial web spinners produce catching silks with a spectral peak in the ultraviolet, whereas the derived Araneoidea produce silks with flat spectra or reduced ultraviolet reflectance; the araneoid shift coincided with a 37-fold increase in species number and apparent habitat expansion[10](https://academic.oup.com/evolut/article/48/2/287/6869950?searchresult=1).
## Life cycle and distribution
After mating, the female constructs strong, spherical, brown-flecked egg sacs, each suspended among low foliage by a short silk stalk and disguised with leaf debris. Net-casting spiders mature in summer, when mating and egg-laying occur[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/). In Australia, net-casting spiders are widely distributed in forest habitats of the southeast and are often seen on fine summer nights among garden shrubs and trees[1](https://australian.museum/learn/animals/spiders/net-casting-spiders/). The species *Deinopis spinosa* is recorded from the United States, Jamaica, St. Vincent, and Venezuela[11](https://www.wsc.nmbe.ch/spec-data/15290).
## References
1. [Net-casting Spiders, Australian Museum](https://australian.museum/learn/animals/spiders/net-casting-spiders/)
2. [Coddington, J. A., Kuntner, M. & Opell, B. D. (2012). Systematics of the spider family Deinopidae with a revision of the genus Menneus. Smithsonian Contributions to Zoology 636.](https://www.si.edu/object/systematics-spider-family-deinopidae-revision-genus-menneus-jonathan-coddington-matjaz-kuntner-and%3Asiris_sil_988848)
3. [Integrated Taxonomic Information System: Deinopidae](https://www.itis.gov/servlet/SingleRpt/SingleRpt?anchorLocation=SubordinateTaxa&credibilitySort=TWG+standards+met&print_version=SCR&rankName=Species&search_topic=TSN&search_value=847716&source=from_print)
4. [World Spider Catalog: Generic list of Deinopidae](https://wsc.nmbe.ch/gen-list/25/Deinopidae)
5. [Lin & Li (2020). Asianopis gen. nov., a new genus of the spider family Deinopidae from Asia.](https://pmc.ncbi.nlm.nih.gov/articles/PMC7031397/)
6. [Nocturnal foraging enhanced by enlarged secondary eyes in a net-casting spider](https://pmc.ncbi.nlm.nih.gov/articles/PMC4892245/)
7. [Morehouse, N. I. (2020). Spider vision. Current Biology.](https://homepages.uc.edu/~morehonn/wp-content/uploads/2021/02/Morehouse-NI-2020-Curr-Biol.pdf)
8. [University of Florida IFAS: Deinopis spinosa factsheet](https://edis.ifas.ufl.edu/publication/IN1356/pdf)
9. [Sensory system plasticity in a visually specialized, nocturnal spider](https://pmc.ncbi.nlm.nih.gov/articles/PMC5399460/)
10. [Evolutionary shifts in the spectral properties of spider silks. Evolution (1994).](https://academic.oup.com/evolut/article/48/2/287/6869950?searchresult=1)
11. [World Spider Catalog: Deinopis spinosa](https://www.wsc.nmbe.ch/spec-data/15290)
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*Topic: Encyclopedia › Life and health › Animals › Invertebrates › Arthropods › Arachnids › Spiders › Major spider lineages › Web-building spiders › Specialized silk-capture web users*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 11, 2026; Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license