Biology:Trichonephila clavata

Short description: Species of spider

Trichonephila clavata
Female
Scientific classification
Domain:	Eukaryota
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 Nephila limbata Nephila obnubila Nephila clavatoides Nephila clavata cavalierei

Trichonephila clavata, also known as the Joro spider (ジョロウグモ（女郎蜘蛛、上臈蜘蛛, Jorō-gumo), is a member of the Trichonephila genus. The spider can be found throughout Japan (except Hokkaidō), Korea, Taiwan, China , As of October 2022, T. clavata's range spans at least 120,000 km² (46,000 sq mi), occurring across Georgia, South Carolina, North Carolina, and Tennessee, with additional reports in Alabama, Maryland, Oklahoma, and West Virginia. Its pattern of spread suggests it is primarily driven by natural dispersal mechanisms, such as ballooning, though human-mediated transport cannot be discounted. Due to its large size and the bright, unique colors of the female Trichonephila, the spider is well-favored in Japan.

Scientists confirmed the first known occurrence of T. clavata in North America In 2014,and in 2019, this species was moved from the genus Nephila to Trichonephila. T. clavata's congener Trichonephila plumipes is commonly found in Australia. It also was moved from Nephila to Trichonephila, along with 10 other species.

Characteristics

Female seen from below

Trichonephila clavata pass winter as eggs and scatter as tiny juveniles in the spring. The adult female's body size is 17–25 mm, while the male's is 7–10 mm.

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.

The adult female individual has stripes of yellow and dark blue, with red toward the rear of the abdomen. In autumn, smaller males may be seen in the webs of the females for copulating. After mating, the female spins an egg sack on a tree, laying 400 to 1500 eggs in one sack. Her lifecycle ends by late autumn or early winter with the death of the spider. The next generation emerges in spring.

Although the spider is not aggressive, they will bite to protect themselves. The bite is considered painful, but not life-threatening.

Silk strength and applications

Researchers led by Masao Nakagaki at Shinshu University, Japan, have succeeded in creating a silk thread that is stronger, softer, and more durable than conventional silk by injecting silkworm eggs with genes of the Jorō spider. The silkworms that hatch weave cocoons containing 10% spider protein. The dragline silk is said to have many uses, such as for bulletproof vests, sutures after an operation, fishing line, nets, and tennis rackets. A Japanese manufacturer, Okamoto, began developing commercial applications for the silk and planned to release extra-thin, durable spider socks by 2010.

In folklore

Jorōgumo is a legendary creature in Japanese folklore. A Jorōgumo is a spider who can change her appearance into that of a beautiful woman. She's said to breathe fire and to be able to control other spiders. She seeks men to seduce, whom she then binds in her silk and devours.

File:Joro Spider (Nephila clavata).webm

Introduced species in North America

The spider is an introduced species in northeast Georgia and northwest / upstate South Carolina in North America. They were first spotted in Hoschton, Georgia in 2013. Since then, they have been spotted in numerous locations in northeast Georgia, including the Athens, Georgia area, and also in Greenville, South Carolina. It is believed that the species will become naturalized. They are expected to colonize much of the Eastern Seaboard of the United States due to their relative imperviousness to the cold.

As of 2022, their impact on their new ecosystem is unknown. They have been observed catching the brown marmorated stink bug (Halymorpha halys), an invasive species that native spiders have not been known to eat, and it has also been hoped that they may consume mosquitoes and flies. Some hope that the impact of the species will be positive due to their harmless nature and consumption of primarily invasive or nuisance insects; however, because of the relative lack of information about its ecology, the effects the spider will have on ecosystems are unknown.

Gallery

• 

  Female in Ibaraki, Japan

• 

  Female spider with two males in Tokyo, Japan

• 

  Female spider found at Bukhansan National Park, Seoul, South Korea .

• 

  Female at a military base in Aibano, Japan

• 

  Female with a male in the background on Enoshima-Isle, Japan

• 

  Female eating a ladybug in South Korea

• 

  Web on electric power cable in Tanabe, Wakayama

• 

  Female in Rikugien

• 

  Juvenile female in Duluth, Georgia

See also

• Joro toxin
• Tegenaria parietina

External links

• Big Yellow Spiders in South Carolina Home and Garden Information Center, Clemson University

Wikidata ☰ {{{from}}} entry