Trichonephila inaurata

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Red-legged golden orb-weaver spider
Nephila inaurata dsc07682.jpg
Nominate subspecies in Réunion
Golden orb-weaver spider (Nephila inaurata madagascariensis) female 3.jpg
T. i. subsp. madagascariensis in Madagascar
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Nephilidae
Genus: Trichonephila
Species:
T. inaurata
Binomial name
Trichonephila inaurata
(Walckenaer, 1842) [1]
Synonyms

Epeira inaurata
Epeira geniculata
Epeira nigra
Nephila ardentipes
Nephila inaurata
Araneus geniculatus

Contents

Trichonephila inaurata, synonym Nephila inaurata, [1] commonly known as the red-legged golden orb-weaver spider or red-legged nephila,[ citation needed ] is a species of spider of the genus Trichonephila . It is native to southern and East Africa, as well as several islands of the western Indian Ocean (Madagascar, the Seychelles, Réunion, Mauritius, Rodrigues). [1] [2]

Web spinning and structure

Trichonephila spiders produce large asymmetric orb webs up to 1.5 m (5 ft) in diameter.[ citation needed ]Trichonephila species remain in their webs permanently, so have a higher predation risk. The golden silk orb-weaver is named for the yellow color of the spider silk used to construct these webs.

Yellow threads of their web shine like gold in sunlight. Carotenoids are the main contributors to this yellow color, but xanthurenic acid, two quinones, and an unknown compound may also aid in the color. [3] Experimental evidence suggests that the silk's color may serve a dual purpose: sunlit webs ensnare bees that are attracted to the bright yellow strands, whereas in shady spots, the yellow blends in with background foliage to act as a camouflage. The spider is able to adjust pigment intensity relative to background light levels and color; the range of spectral reflectance is specifically adapted to insect vision.

The webs of most Trichonephila spiders are complex, with a fine-meshed orb suspended in a maze of non-sticky barrier webs. As with many weavers of sticky spirals, the orb is renewed regularly if not daily, apparently because the stickiness of the orb declines with age. When weather is good (and no rain has damaged the orb web), subadults and adults often rebuild only a portion of the web. The spider removes and consumes the portion to be replaced, builds new radial elements, then spins the new spirals. This partial orb renewal is distinct from other orb-weaving spiders that usually replace the entire orb web. The web of Nephila antipodiana contains ant-repellent chemicals to protect the web. [4]

Typically, the golden orb-weaver first weaves a nonsticky spiral with space for two to 20 more spirals in between (the density of sticky spiral strands decreases with increasing spider size).[ citation needed ] When she has completed the coarse weaving, she returns and fills in the gaps. Whereas most orb-weaving spiders remove the nonsticky spiral when spinning the sticky spiral, Trichonephila spiders leave it. This produces a "manuscript paper" effect when the orb is seen in the sun: groups of sticky spirals reflecting light with "gaps" where the nonsticky spiral does not reflect the light.

In relation to the ground, the webs of adults may be woven from eye-level upwards high into the tree canopy. The orb web is usually truncated by a top horizontal support strand, giving it an incomplete look.

Adjacent to one face of the main orb, a rather extensive and haphazard-looking network of guard-strands may be suspended a few cm distant across a free space. This network is often decorated with a lumpy string or two of plant detritus and insect carcasses clumped with silk. This "barrier web" may function as a kind of early-warning system for incoming prey or against spider-hunting predators, or as a shield against windblown leaves; it may also be remnants of the owner's previous web. At least one reference explains the suspended debris-chain as a cue for birds to avoid blundering into and destroying the web.

Habits

Like other spiders in the subfamily Nephilinae, it can weave webs so strong that sometimes even birds and bats get caught.[ citation needed ] Its webs can be found in damp places such as large trees and unpolluted areas to which no cars have access; normally several are strung together to form enormous "homes" so as to cover as much surface area as possible.[ citation needed ]

Prey

This species feeds on flies, mosquitoes, moths, wasps and beetles who happen to get tangled up.

Subspecies

In addition to the nominate subspecies (T. i. inaurata) of Mauritius and Réunion, [5] a second subspecies is currently recognized: T. i. madagascariensis (Vinson, 1863), which occurs from South Africa to the Seychelles.

Captive breeding

This species is commonly kept in captivity. Egg sacs the size of a small marble are made of thick silk and contain 100-200 eggs which hatch after two months. They start out with a 2mm leg span and grow rapidly. Males mature in one to two months depending on the form. A small percentage of males mature early and resemble a small, black crab spider with only an 8-10mm leg span. Most males mature later and resemble the form of the female but have very little color and only a 25-30mm leg span. Females mature in four months with an approximate 100mm leg span. [6]

Related Research Articles

<span class="mw-page-title-main">Orb-weaver spider</span> Family of spiders

Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs.

<i>Nephila</i> Genus of spiders

Nephila is a genus of araneomorph spiders noted for the impressive webs they weave. Nephila consists of numerous species found in warmer regions around the world, although some species formerly included in the genus have been moved to Trichonephila. They are commonly called golden silk orb-weavers, golden orb-weavers, giant wood spiders, or banana spiders.

Banana spider may refer to:

<i>Trichonephila clavata</i> Species of spider

Trichonephila clavata, also known as the Joro spider (ジョロウグモ , is a member of the Trichonephila genus. The spider can be found throughout Japan, Korea, Taiwan, China. As of October 2022, T. clavata's range spans at least 120,000 km2, 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.

<i>Trichonephila clavipes</i> Species of spider native to the Americas

Trichonephila clavipes, commonly known as the golden silk orb-weaver, golden silk spider, or banana spider, is an orb-weaving spider species which inhabits forests and wooded areas ranging from the southern US to Argentina. It is indigenous to both continental North and South America. Known for the golden color of their silk, the large size of their females, and their distinctive red-brown and yellow coloring, T. clavipes construct large, asymmetrical circular webs attached to trees and low shrubs in woods to catch small- and medium-size flying prey, mostly insects. They are excellent web-builders, producing and utilizing seven different types of silk, and they subdue their prey by injecting them with venom, as opposed to related species which immobilize their prey by wrapping them in silk first. They are not known to be aggressive towards humans, only biting out of self-defense if touched, and their relatively harmless venom has a low toxicity, posing little health concern to healthy human adults. Due to their prevalence in forests, T. clavipes may be encountered by hikers.

<i>Zygiella x-notata</i> Species of spider

Zygiella x-notata, sometimes known as the missing sector orb weaver or the silver-sided sector spider, is a spider species in the family Araneidae. They are solitary spiders, residing in daily-spun orb webs. Z. x-notata is a member of the genus Zygiella, the orb-weaving spiders. The adult female is easily recognized by the characteristic leaf-like mark on her posterior opisthosoma, caudal to the yellow-brown cephalothorax.

<i>Trichonephila edulis</i> Species of spider

Trichonephila edulis is a species of large spider of the family Nephilidae, formerly placed in the genus Nephila. It is referred to by the common name Australian golden orb weaver. It is found in Indonesia from Java eastwards, Papua New Guinea, Australia, northern New Zealand, and New Caledonia.

<span class="mw-page-title-main">Barn spider</span> Species of spider

The barn spider is a common orb-weaver spider native to North America. They are around three-quarters of an inch (20 mm) in length and are usually yellow and brown in color. They often construct their webs in wooden human structures, hence their common name. The species is notable for being the basis for the character Charlotte in the book Charlotte's Web by American writer E. B. White.

<i>Nephila pilipes</i> Species of spider

Nephila pilipes is a species of golden orb-web spider. It resides all over countries in East and Southeast Asia as well as Oceania. It is commonly found in primary and secondary forests and gardens. Females are large and grow to a body size of 30–50 mm, with males growing to 5–6 mm. It is the second largest of the orb-weaving spiders apart from the recently discovered Nephila komaci. The first, second, and fourth pairs of legs of juvenile females have dense hairy brushes, but these brushes disappear as the spider matures.

<i>Trichonephila plumipes</i> Species of spider

Trichonephila plumipes, the Pacific golden orb weaver, is a species of spider found in Australia, Indonesia and some Pacific Islands, which exhibits extreme sexual dimorphism through its sexual cannibalism behavior. It is sometimes called the tiger spider due to its markings which look similar to a tiger. This species was formerly called Nephila plumipes. As with other spiders from the genus Nephila, these spiders have a distinct golden web.

<span class="mw-page-title-main">Spider web</span> Structure created by a spider from silk

A spider web, spiderweb, spider's web, or cobweb is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey.

<i>Nephila komaci</i> Species of spider

Nephila komaci is a species of golden orb-web spider. It is the largest web-spinning spider known. A few specimens have been found in South Africa and Madagascar.

Nephila antipodiana, also known as the batik golden web spider, is a species of golden orb-web spider discovered in 1841 by Charles Athanase Walckenaer. The species is found throughout Australia, China, Indonesia, the Philippines, and Thailand. The spider's silk contains a pyrrolidine alkaloid which serves as a chemical repellent to keep ants away from the spider's web.

<i>Cyrtophora moluccensis</i> Species of spider

Cyrtophora moluccensis is a tent-web spider in the orb-weaver family. It is commonly known as the tent spider or dome-web spider, and is native to India, Japan, Indonesia, Papua New Guinea, Australia, Fiji, and Tonga. It is often found in disturbed or open habitats from coasts to forest and mountainous interiors.

<i>Leucauge fastigata</i> Species of spider

Leucauge fastigata, the pear-shaped leucauge, is a species of spiders in the family Tetragnathidae. Its native range extends from India to the Philippines and Sulawesi.

<i>Tetragnatha versicolor</i> Species of spider

Tetragnatha versicolor is a species of long-jawed orb weaver in the spider family Tetragnathidae. It is found throughout North America, Canada, Central America, and Cuba, but are most common in the United States. T. versicolor is heavily concentrated in New England and the west coast in states like California and Washington. T. versicolor is considered a habitat generalist, and can thrive in many different environments. While they can be found in places like Grasslands, Wetlands, Forests, etc., they prefer dryer areas like normal trees and shrubs. Unlike other spiders in the genus Tetragnatha, T. versicolor will rarely reside near aquatic environments. T. versicolor will typically be colored dark yellow or pale orange and average around 5 mm for males and 6.5 mm for females in length, which is very small for a spider. They are much longer than they are wide, making them very distinct. In addition, T. versicolor can be distinguished from other spiders in Tetragnatha by the distinct separation of the anterior/posterior eyes and the appearance of their reproductive organs. As an orb weaver spider, T. versicolor creates a web to hunt for prey. It will wait at night for prey to stumble into its web and use vibrational signals throughout the web to sense trapped prey. In terms of mating behavior, T. versicolor lacks a distinct courting ritual and will mate with any others in the proximity. Mating behavior is heavily affected by female mating history. In terms of interactions with humans, the bite of T. versicolor is venomous, but not known to cause significant harm.

<i>Trichonephila</i> Genus of spiders

Trichonephila is a genus of golden orb-weaver spiders that was first described by Friedrich Dahl in 1911, as a subgenus of Nephila. Trichonephila was elevated to the level of genus by Kuntner et al. in 2019. The genus Trichonephila belongs to the Nephilidae family.

<i>Leucauge mariana</i> Species of spider

Leucauge mariana is a long-jawed orb weaver spider, native to Central America and South America. Its web building and sexual behavior have been studied extensively. Males perform several kinds of courtship behavior to induce females to copulate and to use their sperm.

<i>Cyrtarachne nagasakiensis</i> Species of spider

Cyrtarachne nagasakiensis is a species of spider in the orb-weaver spider family Araneidae, found in Pakistan, India, China, Korea and Japan. Spiders in the genus Cyrtarachne construct "spanning-thread webs" rather than the more typical orb webs of the family Araneidae. These webs have a small number of radii and instead of a tight spiral of sticky threads, the sticky spanning threads are widely spaced and do not form a spiral. When prey is caught on one of the spanning threads, one end comes loose, and the prey, often a moth, dangles from the other end until hauled in by the spider.

<i>Cyrtarachne yunoharuensis</i> Species of spider

Cyrtarachne yunoharuensis is a species of spider in the orb-weaver spider family Araneidae, found in China, Korea and Japan. Spiders in the genus Cyrtarachne construct "spanning-thread webs" rather than the more typical orb webs of the family Araneidae. These webs have a small number of radii and instead of a tight spiral of sticky threads, the sticky spanning threads are widely spaced and do not form a spiral. When prey is caught on one of the spanning threads, one end comes loose, and the prey, often a moth, dangles from the other end until hauled in by the spider.

References

  1. 1 2 3 "Taxon details Trichonephila inaurata (Walckenaer, 1841)", World Spider Catalog, Natural History Museum Bern, retrieved 2021-10-24
  2. "Taxon details Trichonephila inaurata madagascariensis (Vinson, 1863)", World Spider Catalog, Natural History Museum Bern, retrieved 2021-10-24
  3. Hsiung, Bor-Kai; Justyn, Nicholas M.; Blackledge, Todd A.; Shawkey, Matthew D. (2017-06-01). "Spiders have rich pigmentary and structural colour palettes". Journal of Experimental Biology. 220 (11): 1975–1983. doi: 10.1242/jeb.156083 . PMID   28566355.
  4. Phillips, Campbell (23 November 2011). "Golden orb web spider spins ant-repellent silk". Australian Geographic. Retrieved 16 August 2012.
  5. "Family: Araneidae Clerck, 1757". World Spider Catalog Version 19.0. Natural History Museum Bern. 2018. Retrieved 5 July 2018.
  6. "Golden Silk Spiders", Invertebrate-Magazine Vol.4, Issue 2 March 2005