Trichonephila clavata

Trichonephila clavata
Female
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Nephilidae
Genus: Trichonephila
Species:
T. clavata
Binomial name
Trichonephila clavata
(L. Koch, 1878)
Synonyms
  • Nephila clavata L. Koch, 1878
  • Nephila limbata Thorell, 1898
  • Nephila obnubila Simon, 1906
  • Nephila clavatoides Schenkel, 1953
  • Nephila clavata cavalierei Schenkel, 1963
  • Argiope maja Bösenberg & Strand, 1906

Trichonephila clavata (T. clavata), also known as the Joro spider (ジョロウグモ, Jorō-gumo), is native to East Asia, specifically China, Japan (except Hokkaidō), Korea, and Taiwan.They have been spreading across North America since the 2010s and can now be found across the Eastern United States.

T. clavata are in the Orbweaver family which are not known to inflict medically significant bites or show signs of aggression in their native range.

Appearance

Female seen from below

T. clavata exhibit extreme sexual dimorphism. The adult female's body size is 17–30 millimeters (0.67–1.2 in) while the male's is 4–8 millimeters (0.16–0.31 in). Both males and females have a large, slender abdomen and long legs. The adult female has a yellow abdomen with dark blue or green stripes and red markings toward the rear of the abdomen. Her legs are slender and are black with bands of golden yellow. Males are duller in color; light brown with a dark brown stripe running down the abdomen.

The web of females may reach several meters in length. In sunlight, the yellow threads appear to be a rich gold color. The structure of the web seen in cross-section is unusual for an orb web; it has three layers: the central orb, plus two irregular layers in front and behind the orb. Males rely on females for webs as they do not construct their own.

Life History

Life Cycle

On average, the lifecycle of T. clavata lasts for approximately one year. Females lay their eggs in autumn before temperatures drop, and the cluster overwinters in egg sacs before emerging as tiny juveniles in spring. In autumn, males may be seen in the webs of mature females for copulating, which typically occurs directly after the female’s final molt. After mating, the female spins a single egg sac on a tree, laying 400 to 1,500 eggs in one sac before her lifecycle ends in late autumn or early winter.

Behavior (Mating and Feeding)

If multiple males are drawn to the same female, they will often compete for the chance to mate; the largest male will typically be victorious.

Relationship to humans

Risks to people

The bite of T. clavata does not pose significant risks to humans. Although they can occasionally puncture skin, they are reluctant to bite. When bites do occur, the venom is weak and not medically significant. The temporary pain and redness has been compared to that of a bee sting.

They were previously in the family Nephilidae before being moved to the genus Trichonephilia, which could potentially pose a higher risk of uncharacterized traits. Spiders listed in Nephilidae have been seen feeding on amphibians, small birds and mammals more commonly than previously thought. With the concern of the potential harm they could inflict on small invertebrates, monitoring the effects on humans is still recommended.

In folklore

The common name of the spider comes from the jorōgumo, a legendary spider in Japanese folklore that can transform into a beautiful woman who can breathe fire and control other spiders. She seeks men to seduce, whom she then binds in her silk and devours.

Joro spider moving on a branch in Kanagawa, Japan

Use

T. clavata is a food for the Ao-Nagas.

Distributions and Habitats

Introduced Species in North America

The Joro spider is an introduced species in northeast Georgia and northwest/upstate South Carolina, in the United States. They were first spotted in Hoschton, Georgia, in 2013. Since then, they have been seen in numerous locations in northeast Georgia, including the Athens area and also in Greenville, South Carolina. While the Joro spider was first observed in the warm climates of the Gulf and lower East Coast of the US, it is now expected to colonize much of the middle East Coast due to its cold tolerance.

Scientists confirmed the first known occurrence of T. clavata in North America in 2014, and as of October 2022, the spider's range spans at least 120,000 km2 (46,000 sq mi), occurring across the U.S. states of Georgia, South Carolina, North Carolina, and Tennessee, with additional reports in Alabama, Maryland, Oklahoma, West Virginia, and Pennsylvania. The most likely cause of their invasion is through shipping containers from China, Japan, or Korea as well as natural dispersal mechanisms, such as ballooning.

As of 2022, because of the relative lack of information about the Joro spider's ecology, the impact it has on its new ecosystem is unknown.

See also

References

  1. ↑ Kuntner, M.; Rudolf, E.; Cardoso, P. (2017). "Nephila clavata". IUCN Red List of Threatened Species. 2017 e.T89292211A89292868. doi:10.2305/IUCN.UK.2017-1.RLTS.T89292211A89292868.en. Retrieved 25 July 2023.
  2. 1 2 "Taxon details Trichonephila clavata (L. Koch, 1878)". World Spider Catalog. Natural History Museum Bern. Retrieved 14 May 2017.
  3. 1 2 Nelsen, David R; Chuang, Angela; Corbit, Aaron G; Sitvarin, Michael I; Bergmann, Hannah E; De Araujo, Everaldo P; Hunter, Sarah R; Ing, Jared K; Park, Justin J; Vasquez, Kaitlyn A; Wang, Amani S; Coyle, David R (1 November 2025). "Keep calm and carry on: bites from Trichonephila clavata are unlikely and cause minimal discomfort". Journal of Medical Entomology. 62 (6): 1396–1408. doi:10.1093/jme/tjaf103. ISSN 0022-2585. PMC 12616235. PMID 41123166.
  4. 1 2 Schmidt, Rebekah Danielle Wallace, Richard Hoebeke, Jason (27 August 2026). "Joro Spider: Trichonephila clavata". CAES Field Report. Retrieved 19 October 2026.{{cite web}}: CS1 maint: multiple names: authors list (link)
  5. 1 2 3 4 5 Miyashita, Tadashi (1993). "Male‐male competition and mating success in the orb‐web spider, Nephila clavata , with reference to temporal factors". Ecological Research. 8 (1): 93–102. doi:10.1007/bf02348612. ISSN 0912-3814.
  6. ↑ "Jorō Spiders". Penn State College of Agricultural Sciences. Pennsylvania State University. Retrieved 7 June 2024.
  7. ↑ Nyffeler, Martin; Gibbons, J. Whitfield (2022). "Spiders feeding on vertebrates is more common and widespread than previously thought, geographically and taxonomically". The Journal of Arachnology. 50 (2). doi:10.1636/JoA-S-21-054.
  8. ↑ "The Legend of the Jorōgumo". Joro Spider Information. Retrieved 17 June 2022.
  9. ↑ V.B.MEYER-ROCHOW (2004). "19 Traditional Food Insects and Spiders in Several Ethnic Groups of Northeast India, Papua New Guinea, Australia and New Zealand" (PDF). In Maurizio G. Paoletti (ed.). Ecological Implications of Minilivestock: Rodents, Frogs, Snails, and Insects, for Substainable Development. University of Oulu & International University of Bremen: Science Publishers, 6000 Broken Sound Parkway NW, Boca Raton; an imprint of CRC Press. p. 391.
  10. ↑ Romo, Rebecca (9 March 2022). "No, you don't need to worry about joro spiders. They may even be helpful in some ways". NPR. Retrieved 9 March 2022.
  11. ↑ Gravrilles, Beth (26 October 2020). "Like it or not, Joro spiders are here to stay". UGA TODAY. Athens, Georgia. Retrieved 30 September 2021.
  12. ↑ Hoebeke ER, Huffmaster W, Freeman BJ (5 February 2015). "Trichonephila clavata L Koch, the Joro Spider of East Asia, newly recorded from North America (Araneae: Nephilidae)". PeerJ. 3 e763. doi:10.7717/peerj.763. PMC 4327315. PMID 25699210.
  13. ↑ Hoebeke, E. Richard; Huffmaster, Wesley; Freeman, Byron J. (2015). "Nephila clavata L Koch, the Joro Spider of East Asia, newly recorded from North America (Araneae: Nephilidae)". PeerJ. 3 e763. Bibcode:2015PeerJ...3.e763H. doi:10.7717/peerj.763. ISSN 2167-8359. PMC 4327315. PMID 25699210.