St Andrew's Cross Spider

The genus ''Argiope'' includes rather large spiders that often have a strikingly coloured abdomen. These spiders are distributed throughout the world. Most countries in tropical or temperate climates host one or more species that are similar in appearance. The etymology of ''Argiope'' is from a Latin word ''argentum'' meaning silver. The carapace of ''Argiope'' species is typically covered in silvery hairs, and when crawling in the sun, they reflect it in a way that gives them a metallic, white appearance.

Description

As most orb weavers, they own a third claw which is used to weave their complex webs. As most spiders, there is also a significant amount of sexual dimorphism, females measuring 19 to 28mm and males measuring 5 to 9mm. Their webs are relatively big, usually with zigzag patterns in them. They own black and yellow patterning all around their body, occasionally on their legs. Their legs mainly being black, with red or yellow patterning closer to the body. Their cephalothorax is covered with short silver hairs, and they own an egg shape abdomen.

Common names

''Argiope bruennichi'' is commonly known as the wasp spider. In Australia, ''Argiope keyserlingi'' and ''Argiope aetherea'' are known as St Andrew's cross spiders, for their habit of resting in the web with paired legs outstretched in the shape of an X and mirroring the large white web decoration (the cross of St. Andrew having the same form). This white zigzag in the centre of its web is called the ''stabilimentum'' or web decoration.

In North America, ''Argiope aurantia'' is commonly known as the black and yellow garden spider, zipper spider, corn spider, or writing spider, because of the similarity of the web stabilimenta to writing.

The East Asian species ''Argiope amoena'' is known in Japan as ''kogane-gumo''. In the Philippines, they are known as ''gagambang ekis'' ("X spider"), and ''gagambang pari'' ("priest spider", due to the spider's body resembling a priest's head with a mitre).

Web

The average orb web is practically invisible, and it is easy to blunder into one and end up covered with a sticky web. The visible pattern of banded silk made by ''Argiope'' is pure white, and some species make an "X" form, or a zigzag type of web (often with a hollow centre). The spider then aligns one pair of its legs with each of the four lines in the hollow "X", making a complete "X" of white lines with a very eye-catching spider forming its centre.

The zigzag patterns, called stabilimenta, reflect UV light. They have been shown to play a role in attracting prey to the web, and possibly in preventing its destruction by large animals. The centres of their large webs are often just under 1 metre above the ground, so they are too low for anything much larger than a rabbit to walk under. The overtness of the spider and its web thus has been speculated to prevent larger creatures from accidentally destroying the web and possibly crushing the spider underfoot.

Other studies suggest that the stabilimenta may actually lead predators to the spider; species such as ''A. keyserlingi'' place their web predominantly in closed, complex habitats such as among sedges.

As ''Argiope'' sit in the centre of their web during the day, they have developed several responses to predators, such as dropping off the web, retreating to the periphery of the web, or even rapidly pumping the web in bursts of up to 30 seconds, similar to the motion done by the unrelated ''Pholcus phalangioides''.

File:Florida Argiope - Argiope florida, Archbold Biological Station, Venus, Florida - 01.jpg, ''Argiope florida''
File:Writing Spider.jpg, Writing spider on stabilimentum in Iowa
File:Silver argiope (Argiope argentata).jpg, Silver argiope (''Argiope argentata'') in Jamaica
File:Writing Spider Argiope.jpg, Writing spider in South Carolina
File:Argiope keyserlingi 5367.jpg, St Andrew's cross spider (''Argiope keyserlingi''), Australia
File:Spider DNS SC.jpg, alt=Argiope in Goose Creek, SC., ''Argiope spp. spider'' Found in Goose Creek, South Carolina in October of 2019.

Reproduction

The male spider is much smaller than the female, and unassumingly marked. When it is time to mate, the male spins a companion web alongside the female's. After mating, the female lays her eggs, placing her egg sac into the web. The sac contains between 400 and 1400 eggs.

These eggs hatch in autumn, but the spiderlings overwinter in the sac and emerge during the spring. The egg sac is composed of multiple layers of silk and protects its contents from damage; however, many species of insects have been observed to parasitise the egg sacs.

Bite

Like almost all other spiders, ''Argiope'' are harmless to humans. As is the case with most garden spiders, they eat insects, and they are capable of consuming prey up to twice their size. ''A. savigny'' was even reported to occasionally feed on the small bat ''Rhynchonycteris naso''.

They can potentially bite if grabbed, but other than for defense, they do not attack large animals. Their venom is not regarded as a serious medical problem for humans; it often contains a wide variety of polyamine toxins with potential as therapeutic medicinal agents. Notable among these is the argiotoxin ArgTX-636 (''A. lobata'').

A bite by the black and yellow garden spider (''Argiope aurantia'') is comparable to a bee sting, with redness and swelling. For a healthy adult, a bite is not considered an issue.

Though they are not aggressive spiders, the very young, elderly, those with compromised immune systems, or those with known venom allergies should exercise caution, just as one would around a beehive.

Taxonomy

The first description of the genus ''Argiope'' is attributed to Jean Victoire Audouin in 1826, although he wrote that the genus was established by Savigny. In the first edition of the work in which the description appeared (''Description de l'Égypte: Histoire Naturelle''), Audouin used the spelling "Argyope", for both the French vernacular name and the Latin generic name. In the second edition, he continued to use "Argyope" for the French vernacular name, but the first mention of the Latin generic name had the spelling "''Argiope''", although the binomial names of the species continued to use "''Argyope''". This led to controversy as to whether Audouin had intended to correct the spelling of the generic name, which is derived from the Greek αργιόπη. In 1975, the International Commission on Zoological Nomenclature validated the spelling "''Argiope''", on the basis that the change from the first to the second edition was an intended correction.

Species

, ''Argiope'' contains 88 species:

*'' A. abramovi'' Logunov & Jäger, 2015 – Vietnam
*'' A. aemula'' (Walckenaer, 1841) – India to Philippines, Indonesia (Sulawesi), Vanuatu
*'' A. aetherea'' (Walckenaer, 1841) – China to Australia
*'' A. aetheroides'' Yin, Wang, Zhang, Peng & Chen, 1989 – China, Japan
*'' A. ahngeri'' Spassky, 1932 – Iran, Kyrgyzstan, Turkmenistan, Uzbekistan, Tajikistan?
*'' A. amoena'' L. Koch, 1878 – China, Korea, Taiwan, Japan
*'' A. anasuja'' Thorell, 1887 – Seychelles to India, Pakistan, Maldives
*'' A. anomalopalpis'' Bjørn, 1997 – Congo, South Africa
*'' A. appensa'' (Walckenaer, 1841) – Hawaii, Taiwan to New Guinea
*'' A. argentata'' (Fabricius, 1775) – USA to Chile, Argentina
*'' A. aurantia'' Lucas, 1833 – Canada to Costa Rica
*'' A. aurocincta'' Pocock, 1898 – Central, East, Southern Africa
*'' A. australis'' (Walckenaer, 1805) – Central, East, Southern Africa, Cape Verde Is.
*'' A. bivittigera'' Strand, 1911 – Indonesia
*'' A. blanda'' O. Pickard-Cambridge, 1898 – USA to Costa Rica
*'' A. boesenbergi'' Levi, 1983 – China, Korea, Japan
*'' A. bougainvilla'' (Walckenaer, 1847) – New Guinea to Solomon Is.
*'' A. bruennichi'' (Scopoli, 1772) – Europe, Turkey, Israel, Russia (Europe to Far East), Iran, Central Asia to China, Korea, Japan
*'' A. brunnescentia'' Strand, 1911 – New Guinea, Papua New Guinea (Bismarck Arch.)
*'' A. buehleri'' Schenkel, 1944 – Timor
*'' A. bullocki'' Rainbow, 1908 – Australia (New South Wales)
*'' A. butchko'' LeQuier & Agnarsson, 2016 – Cuba
*'' A. caesarea'' Thorell, 1897 – India, Myanmar, China
*'' A. caledonia'' Levi, 1983 – New Caledonia, Vanuatu
*'' A. cameloides'' Zhu & Song, 1994 – China
*'' A. carvalhoi'' (Mello-Leitão, 1944) – Brazil
*'' A. catenulata'' (Doleschall, 1859) – India to Philippines, New Guinea, Australia
*'' A. chloreis'' Thorell, 1877 – Laos, Indonesia, Papua New Guinea
*'' A. comorica'' Bjørn, 1997 – Comoros, Mayotte
*'' A. coquereli'' (Vinson, 1863) – Tanzania (Zanzibar), Madagascar
*'' A. dang'' Jäger & Praxaysombath, 2009 – Thailand, Laos
*'' A. dietrichae'' Levi, 1983 – Australia (Western Australia, Northern Australia)
*'' A. doboensis'' Strand, 1911 – Indonesia, New Guinea
*'' A. doleschalli'' Thorell, 1873 – Indonesia
*'' A. ericae'' Levi, 2004 – Brazil, Argentina
*'' A. flavipalpis'' (Lucas, 1858) – Africa, Yemen
*'' A. florida'' Chamberlin & Ivie, 1944 – USA
*'' A. halmaherensis'' Strand, 1907 – Indonesia (Moluccas) to New Guinea
*'' A. hinderlichi'' Jäger, 2012 – Laos
*'' A. hoiseni'' Tan, 2018 – Malaysia (Peninsula)
*'' A. intricata'' Simon, 1877 – Philippines
*'' A. jinghongensis'' Yin, Peng & Wang, 1994 – China, Vietnam, Laos, Thailand
*'' A. kaingang'' Corronca & Rodríguez-Artigas, 2015 – Argentina
*'' A. katherina'' Levi, 1983 – Northern Australia
*'' A. keyserlingi'' Karsch, 1878 – Australia (Queensland, New South Wales, Lord Howe Is.)
*'' A. kochi'' Levi, 1983 – Australia (Queensland)
*'' A. legionis'' Motta & Levi, 2009 – Brazil
*'' A. levii'' Bjørn, 1997 – South Africa, Kenya, Tanzania
*'' A. lobata'' (Pallas, 1772) – Southern Europe to Central Asia and China, northern Africa, South Africa, Israel, India, from Myanmar to New Caledonia and northern Australia
*'' A. luzona'' (Walckenaer, 1841) – Philippines
*'' A. macrochoera'' Thorell, 1891 – India (Nicobar Is.), China
*'' A. madang'' Levi, 1984 – New Guinea
*'' A. magnifica'' L. Koch, 1871 – Australia (Queensland) to Solomon Is.
*'' A. mangal'' Koh, 1991 – Singapore
*'' A. manila'' Levi, 1983 – Philippines
*'' A. mascordi'' Levi, 1983 – Australia (Queensland)
*'' A. minuta'' Karsch, 1879 – Bangladesh, East Asia
*'' A. modesta'' Thorell, 1881 – Borneo to Australia
*'' A. niasensis'' Strand, 1907 – Indonesia
*'' A. ocula'' Fox, 1938 – China, Taiwan, Japan
*'' A. ocyaloides'' L. Koch, 1871 – Australia (Queensland)
*'' A. pentagona'' L. Koch, 1871 – Fiji
*'' A. perforata'' Schenkel, 1963 – China
*'' A. picta'' L. Koch, 1871 – Indonesia (Moluccas) to Australia
*'' A. pictula'' Strand, 1911 – Indonesia (Sulawesi)
*'' A. ponape'' Levi, 1983 – Caroline Is.
*'' A. possoica'' Merian, 1911 – Indonesia (Sulawesi)
*'' A. probata'' Rainbow, 1916 – Australia (Queensland)
*'' A. protensa'' L. Koch, 1872 – New Guinea, Australia, New Caledonia, New Zealand
*'' A. pulchella'' Thorell, 1881 – India to China and Indonesia
*'' A. pulchelloides'' Yin, Wang, Zhang, Peng & Chen, 1989 – China
*'' A. radon'' Levi, 1983 – Northern Australia
*'' A. ranomafanensis'' Bjørn, 1997 – Madagascar
*'' A. reinwardti'' (Doleschall, 1859) – Malaysia to New Guinea
**'' Argiope r. sumatrana'' (Hasselt, 1882) – Indonesia (Sumatra)
*'' A. sapoa'' Barrion & Litsinger, 1995 – Philippines
*'' A. sector'' (Forsskål, 1776) – North Africa, Middle East, Cape Verde Is.
*'' A. squallica'' Strand, 1915 – New Guinea
*'' A. submaronica'' Strand, 1916 – Mexico to Bolivia, Brazil
*'' A. takum'' Chrysanthus, 1971 – New Guinea
*'' A. tapinolobata'' Bjørn, 1997 – Senegal, Namibia
*'' A. taprobanica'' Thorell, 1887 – Sri Lanka
*'' A. trifasciata'' (Forsskål, 1775) – North, Central and South America. Introduced to Africa, Portugal to Israel, Iran, China, Japan, Australia (Tasmania), Pacific Is.
**'' Argiope t. deserticola'' Simon, 1906 – Sudan
**'' Argiope t. kauaiensis'' Simon, 1900 – Hawaii
*'' A. truk'' Levi, 1983 – Caroline Is.
*'' A. versicolor'' (Doleschall, 1859) – China to Indonesia (Java)
*'' A. vietnamensis'' Ono, 2010 – Vietnam

Injury and pain

''Argiope'' use autotomy - restricting blood flow to their own leg until it falls off - to minimize blood loss due to injury. This is triggered by pain. Honeybee and wasp venoms induce the same pain in ''Argiope'' - even when the injury is minor - causing ''Argiope'' to drop the affected leg. The same effect can also be produced by chemically fractionated components of those venoms (specifically serotonin, histamine, and phospholipase A2) that also cause pain in humans.

Footnotes

References

* (The actual date of publication to be used in zoological nomenclature is explained in )
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* (''Argiope argentata'')
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External links

Pictures of ''Argiope'' species
— Forestry Images, University of Georgia (free for noncommercial use)
St. Andrews Cross Spider ''Argiope keyserlingii''
— Museum Victoria

{{DEFAULTSORT:Argiope (Spider)

Araneomorphae genera
Cosmopolitan spiders