Spider identification and bite risk
Are Tent-Web Spiders Poisonous or Dangerous?
Tent-web spiders in the genus Cyrtophora possess venom for subduing insect and other small arthropod prey. However, they are not generally considered dangerous to people. They are shy web-building spiders, do not seek out human contact, and a defensive bite—if one occurs—is more likely to produce temporary local symptoms than serious envenomation.
Direct answer: In everyday language, the answer to “are tent spiders poisonous?” is that they do have venom. Scientifically, venomous is the more accurate word because the secretion is delivered through the fangs rather than absorbed or eaten. Their venom is effective against prey, but Australian museum guidance does not treat Cyrtophora tent-web spiders as a medically dangerous group. They should still be left undisturbed and never handled with bare hands. [6]
Are Tent-Web Spiders Dangerous to Humans?
Tent-web spiders are capable of biting, but that is different from being aggressive or medically dangerous. A spider normally uses its fangs and venom against prey. A person is most likely to be bitten only if the spider is trapped against the skin, squeezed, or deliberately handled.
Venomous does not mean dangerous
A venomous animal delivers venom through a bite or sting. The presence of venom alone does not tell us how serious a bite will be for a human. Venom composition, dose, fang penetration and the condition of the person all affect the outcome.
“Harmless” is too absolute
Calling tent-web spiders completely harmless is misleading because a defensive bite may still cause pain, redness, numbness or swelling. A more accurate description is that they are not generally regarded as dangerous to humans.
Classification and the Meaning of “Tent Spider”
Cyrtophora Simon, 1864 is an accepted spider genus in the orb-weaver family Araneidae. The type species is Cyrtophora citricola. “Tent-web spider,” “tent spider” and “dome-web spider” are common names based mainly on web shape, not names for one single species. [1]
Being an orb-weaving spider does not mean that every species must build the familiar vertical, wheel-shaped web with a sticky capture spiral. Cyrtophora constructs a highly modified form of orb web: a dense horizontal sheet or dome, made from fine non-sticky silk, with supporting and interception threads arranged above and sometimes below it. [7] [8] [9]
Common-name warning: Not every spider called a “tent spider” belongs to the same species, and not every tent-shaped web was made by Cyrtophora. Australia also has the separate araneid genus Cyrtobill, whose members may be called small tent-web spiders.
The name “double-tailed tent spider” is commonly used for Cyrtophora exanthematica because of two blunt projections at the rear of its abdomen. It should not be confused with two-tailed or tree-trunk spiders in the family Hersiliidae , which have conspicuously elongated spinnerets and a different body plan, hunting behavior and classification.
What about the tropical tent-web spider?
The common name “tropical tent-web spider” is often applied to Cyrtophora citricola. That name should not automatically be attached to an Australian tent-web spider. The current World Spider Catalog distribution for C. citricola covers southern Europe, Africa, parts of Asia and introduced populations in the Americas, but does not currently list Australia. [1]
Older Australian literature reported C. citricola through synonymy and museum identifications, while later catalogs and regional revisions have changed the treatment of some populations. This is a good example of why a broad common name, a photograph or color pattern alone may not support a confident species-level identification. [7] [12]
Tent-Web Spider Identification
The web is often the strongest field clue. Look for a horizontal, densely woven platform that is raised into a dome, bowl or pointed tent, with irregular support threads crossing the space above it. The spider commonly hangs beneath the sheet, sits near the central peak, or retreats toward leaves and denser silk at the edge.
- A fine horizontal capture sheet rather than a conventional vertical sticky orb.
- A raised central dome, broad bowl or sharply pointed tent, depending on the species and site.
- An irregular framework of interception and supporting threads above the sheet.
- Females that are substantially larger and more conspicuous than adult males.
- A relatively high, humped, angular or patterned abdomen in many species, although color is highly variable.
Three frequently discussed Australian species
| Species | Useful field clues | Typical web clues | Verified distribution context |
|---|---|---|---|
|
Cyrtophora moluccensis Tent spider or dome-web spider | Usually the most conspicuous of the three. Females often have banded legs and a high, strongly patterned abdomen. Individuals may show maroon, black, white, greenish, orange or darker combinations, so color alone is unreliable. | A broad, elevated dome with numerous interception and supporting threads. The spider frequently rests beneath the central area, and egg sacs may be suspended above it. | The World Spider Catalog records a broad Indo-Pacific range from India and Japan through Indonesia, New Guinea and Australia to Pacific islands. An Australian review describes it as common in Queensland. [1] [7] |
|
Cyrtophora hirta Russian tent spider | Generally smaller and paler than a mature C. moluccensis. Field accounts often describe a creamy or pale abdomen, but similar species mean that the web and locality should also be considered. | A relatively compact web with the middle drawn upward into a pointed cone or tent. Dense white silk may form a central retreat. | The current World Spider Catalog lists Queensland and New South Wales. The species was originally described from Bowen, Queensland. [1] [7] |
|
Cyrtophora exanthematica Double-tailed, pan-web or scoop-web spider | Usually brown to orange-brown, although coloration varies. Females have two blunt rear abdominal projections; pale, irregular or wavy longitudinal markings may be visible. | Often less sharply dome-shaped than the other two. The web may be built in dense shrubs, collect leaves and debris, and include a peripheral retreat where the spider hides. | The current catalog summarizes its range from Myanmar to the Philippines and Australia, listing New South Wales. An Australian museum-based review also documented Queensland records and described it as common there. [1] [7] |
These comparisons are suitable for preliminary field identification, not a definitive taxonomic determination. Juveniles, males, color variants and closely related species may require examination of mature anatomical structures by an experienced arachnologist. Regional revisions have also shown that spiders previously placed under one widespread Cyrtophora name may represent different species. [12]
How a Tent or Dome Web Works
The apparent contradiction—“an orb-weaver that does not build an orb web”—comes from confusing family membership with the finished shape of the web. A more accurate description is that Cyrtophora builds a highly modified horizontal orb-web architecture.
Detailed construction research on C. citricola found that the horizontal sheet lacks the sticky capture spiral associated with a conventional orb. Instead, it contains a fine auxiliary spiral and many subsidiary radii. Vertical strands are added above and below the sheet, and flying prey can strike those strands before dropping onto the mesh. [8]
That study also found that a C. citricola web could take several nights to construct and remain functional for weeks. This demonstrates that these webs can be durable, but it should not be converted into a universal construction time or lifespan for every Cyrtophora species. [8]
How large is a tent-web spider web?
There is no scientifically useful rule that every tent web reaches a particular maximum such as four metres. The dimensions depend on the spider’s species and maturity, vegetation, distance between anchor points, weather damage and local prey conditions. Closely positioned individual webs and shared support lines can also create a large web-filled area that is much wider than one spider’s actual capture sheet.
Learn more about the broader function of silk in why spiders build webs .
Distribution and Habitat
The genus Cyrtophora occurs across warm parts of Africa, Asia, Australia, the Pacific and, for some species, introduced areas of the Americas. Individual species have different ranges, so the location of an observation matters. [1]
In Australia, tent-web spiders are especially associated with tropical and subtropical northern and eastern regions, although the genus is not restricted to one climate zone. Australian records include wet and dry forest, open woodland, forest edges, coastal vegetation, shrubs, parks and gardens. Species such as C. moluccensis can adapt well to planted urban vegetation where strong branches and open flight paths provide suitable web sites. [6] [7]
Avoid assuming that every species has the same habitat. For example, field accounts associate C. hirta with dry sclerophyll forest and sharply conical webs, while C. exanthematica is frequently observed in shrub branches where its web can incorporate leaves and debris. [10]
Prey Capture, Diet and Venom
Tent-web spiders are predators of insects and other small arthropods. The upper barrier threads interrupt a flying insect’s path. The insect then falls onto the tightly woven horizontal sheet, where the spider can detect its vibrations, approach from beneath and immobilize it with silk, a bite, or a combination of both. [8]
Typical prey may include flies, moths, beetles, small grasshoppers and other appropriately sized insects entering the web. The exact diet changes with habitat, season, web position and prey availability.
Important correction: It is inaccurate to say that tent-web spider venom “only affects insects.” Venom is adapted primarily for subduing prey, but that does not mean it can have no physiological effect on a person. Mild local symptoms after a defensive bite remain possible. Low medical significance is not the same as zero biological effect.
Reproduction and Egg Sacs
Male Cyrtophora spiders are generally much smaller than mature females and may be found near a female’s web. After mating, the female produces silk-covered egg sacs, but their number, placement, size, coloration and guarding behavior vary among species and individuals.
Australian museum accounts describe females of C. moluccensis and C. hirta placing egg sacs near the central area of their webs. In contrast, C. exanthematica may produce and guard an egg sac in a tangled nursery area or peripheral retreat away from the main capture sheet. [6]
Photographs sometimes show several egg sacs suspended in a line, but there is no reliable genus-wide rule that every female makes exactly four sacs. Nor is there evidence for a universal claim that all females die immediately after laying eggs. Reproductive output and female survival depend on species, age, condition, climate and season.
Tent Spider Bite Risk
Tent-web spiders are shy and normally remain in or retreat through their webs. When disturbed, a spider may run toward an edge, hide among leaves, drop from the web or remain still. It does not chase people or use its bite as a routine form of defense. [6]
Can a tent spider bite?
Yes. Any spider with functional fangs may attempt a defensive bite if squeezed or trapped against the skin. The practical risk is low when the spider and its web are left alone.
What symptoms are possible?
A bite attributed to an orb-weaving spider may cause temporary local pain, redness, numbness, itching, inflammation or swelling. Symptoms and severity can vary, and an unidentified bite should not be diagnosed from an online photograph alone. [11]
Related Australian Museum information describes orb-weavers as reluctant to bite and reports that symptoms are usually negligible or limited to mild local effects. That evidence is useful context, but it should not be misrepresented as proof that every bite from every Cyrtophora species will be symptom-free. [13]
Seek urgent medical help if a bite is followed by difficulty breathing, faintness, confusion, rapidly worsening pain, muscle symptoms, extensive swelling or other severe or spreading effects. In Australia, a suspected funnel-web or large unidentified black-spider bite requires emergency treatment under local guidance. Do not assume that a spider was a tent-web spider simply because a web was nearby.
For broader context, see which spider bites may be dangerous .
How to Handle a Tent-Web Spider Safely
Most outdoor tent-web spiders do not need to be removed. Their webs catch insects, and the spider usually remains in a predictable location away from human contact.
- Leave the spider and web in place when they do not block a doorway, path, play area or frequently used work space.
- Do not grab the spider, egg sacs or central retreat with bare hands.
- Keep children and pets from pulling at the web or trapping the spider against their skin.
- For a difficult indoor location or a spider that cannot be confidently identified, contact a local wildlife handler or pest professional.
- Photograph the spider from a safe distance before relocation when an identification record is useful.
Basic first aid for a minor unidentified spider bite
Queensland health guidance for bites from spiders other than funnel-webs recommends washing the area with soap and water, applying an antiseptic if available, and using a wrapped cold pack to reduce local pain and swelling. Obtain medical or poison-information advice if pain is severe, symptoms persist, infection develops or the spider may be a medically important species. [11]
See the Spiderpedia guide on how to treat a spider bite at home for additional general first-aid context. Online information is not a substitute for diagnosis or emergency care.
Frequently Asked Questions
Are tent spiders poisonous?
Tent-web spiders possess venom, so “venomous” is scientifically more accurate than “poisonous.” They use venom to immobilize prey, but Cyrtophora species are not generally regarded as dangerous to people.
Are tent-web spiders poisonous to humans?
Their venom is primarily used against small arthropod prey. A defensive bite may still cause temporary local pain, redness, numbness or swelling, so it is inaccurate to claim that the venom has no effect on humans.
Are tent spiders dangerous?
They are not considered an aggressive or medically dangerous spider group. Risk is low when the web is left undisturbed, but bare-handed handling should be avoided.
What happens after a tent spider bite?
A bite may cause mild local pain, redness, itching, numbness, inflammation or swelling. Wash the area, use a wrapped cold pack and monitor symptoms. Seek medical advice for severe, spreading or persistent symptoms, or when the spider’s identity is uncertain.
Is a Cyrtophora spider bite medically significant?
Cyrtophora is not normally treated as a medically significant genus. However, bite records are limited, individual reactions vary, and no online article can guarantee the outcome of a particular bite.
Is the tropical tent-web spider poisonous?
The name often refers to Cyrtophora citricola. It uses venom against prey but is not generally considered dangerous to humans. The common name should not automatically be applied to an Australian spider because the current World Spider Catalog does not list Australia in the species’ distribution.
Is a dome-web spider dangerous?
“Dome-web spider” commonly refers to a Cyrtophora species, especially C. moluccensis. These spiders are shy and low-risk, but they can bite defensively if trapped or squeezed.
How can I identify a tent-web spider?
Start with the web: look for a fine horizontal non-sticky sheet raised into a dome or tent, with irregular interception threads above it. Then compare the spider’s abdomen, markings, web retreat, locality and mature anatomy. Do not rely on color alone.
Is a double-tailed tent spider a two-tailed spider?
No. Cyrtophora exanthematica belongs to Araneidae, and its common name refers to paired abdominal projections. True two-tailed or tree-trunk spiders belong to Hersiliidae and have elongated spinnerets.
Related Spiderpedia Guides
Authoritative Sources and Further Reading
Taxonomy and distribution were checked against the current World Spider Catalog in July 2026. Museum pages and peer-reviewed publications were used for Australian identification, web architecture, behavior and bite-risk context.
- World Spider Catalog — Cyrtophora Simon, 1864, family Araneidae, accepted species and distributions .
- Queensland Museum — Tent-web spiders: C. moluccensis, C. hirta and C. exanthematica .
- Framenau, V. W. & Scharff, N. (2009). New orb-weaving spider genus and review of Australian Cyrtophora records. Records of the Western Australian Museum .
- Zschokke, S. (1995). Orb-web construction behavior, including the horizontal non-sticky capture sheet of Cyrtophora citricola .
- Davies, V. T. (1988). An illustrated guide to the genera of orb-weaving spiders in Australia .
- Arachne.org.au — Australian Cyrtophorinae species accounts and field photographs .
- Queensland Poisons Information Centre — Spider-bite symptoms and first-aid guidance .
- Tanikawa, A., Chang, Y. H. & Tso, I. M. (2010). Taxonomic revision of regional spiders previously identified as Cyrtophora moluccensis .
- Australian Museum — Orb-weaver behavior and general bite-risk context .
Editorial identification note: The photographs retained from the original page are described at the tent-web spider or Cyrtophora group level unless a documented specimen record supports a species-level identification. Common names and photograph matching should not replace taxonomic examination.
