Argiope trifasciata

Banded Garden Orb-Web Spider
File:Argiope trifasciata 299192402 539012495.jpg
female
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Scientific classification Edit this classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Family:	Araneidae
Genus:	Argiope
Species:	A. trifasciata
Binomial name
Argiope trifasciata (Forskål, 1775)
Synonyms
A. trifasciata synonyms Argyopes indecissa Forsskål, 1775 Mello-Leitão, 1942 Aranea fastuosa Olivier, 1789 Argiope aurelia Audouin, 1826 Epeira webbii Lucas, 1838 Walckenaer, 1841 Walckenaer, 1841 Walckenaer, 1841 Walckenaer, 1841 Hentz, 1847 Thorell, 1859 Holmberg, 1876 Emerton, 1884 Chamberlin & Ivie, 1944 Argiope argyraspis Argiope stenogastra Epeira argyraspides Epeira flavipes Argiope plana Argiope sticticalis McCook, 1894 Mello-Leitão, 1945 Epeira nephoda Epeira latreilla Epeira mauricia Epeira fastuosa Walckenaer, 1841 Nicolet, 1849 L. Koch, 1867 O. Pickard-Cambridge, 1876 Badcock, 1932 Caporiacco, 1947 Sinha, 1952 Argiope seminola Brachygea platycephala Argiope abalosi Argiope pradhani Argiope simplex Aranea trifasciata Epeira fasciata Argiope avara Argiope transversa

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Ventral view of a female from Portugal

Argiope trifasciata (the banded garden spider or banded orb weaving spider) is a species of spider native to North and South America, but now found around the world.

They typically begin to appear during autumn from early September to late October as temperatures start dropping. In Egypt, the type locality of this spider, females were found surviving the relatively warm winter months.

Their webs can reach a diameter of about 60 cm. The length of the web depends on the size of the spider. Webs are capable of reaching a total length of two meters.

Distribution

Originally from the Americas, Argiope trifasciata was introduced worldwide.

In Europe, it can be found on the Iberian Peninsula, the Canary Islands, and Madeira. The similar looking Argiope bruennichi is common in the Azores.

In Africa, the species is recorded from three countries. In South Africa, the species is known from eight of the nine provinces at elevations ranging from 3 to 1,557 m above sea level.

Habitat and ecology

The species constructs orb webs in wetlands, open grassland areas and gardens. The webs are usually placed low in shrubby vegetation sturdy enough to bear their weight. The spider hangs at the hub head-down throughout the day.

In South Africa, the species inhabits all floral biomes except the Nama Karoo and Succulent Karoo biomes, and has also been collected from crops such as cotton, kenaf, lucerne and tomatoes.

Behavior

• The banded orb weaver wraps up a large milkweed bug and subsequently cuts it from its web
  The banded orb weaver wraps up a large milkweed bug and subsequently cuts it from its web
• Egg sac, photographed in northern Texas
  Egg sac, photographed in northern Texas
• Egg Sacs (Cairo, Egypt)
  Egg Sacs (Cairo, Egypt)

In Illinois, Argiope trifasciata hatches in early summer but does not become readily notable until mid-August, when they have grown large enough to make their distinctive webs, which can be up to 60 cm (24 in) in diameter, among stems and bushes. The female rests at the centre of the web facing downwards, with her legs often arranged in pairs, making a cross shape; some female spiders conceal themselves in a hidden location close to the web, being alerted to a potential victim by a non-sticky thread leading to the center.

Some segments of the web often have thicker threads known as stabilimenta forming a decorative pattern. Male spiders are much smaller than females and have their own small webs in close proximity to the females' webs. Argiope trifasciata is diurnal, and feeds on the insects that get snared in the web. Large, powerful prey like paper wasps, are swiftly wrapped in silk to immobilise them, before being injected with toxic saliva.

• female
  female
• female
  female
• female in web
  female in web
• juvenile
  juvenile
• newly hatched spiderlings
  newly hatched spiderlings

Web silk decorations

The silk decorations of Argiope spiders are thought of as visual signals by researchers. Even though the purpose behind the silk decorations made by Argiope trifasciata remains uncertain, there are a few hypotheses: to make the spider appear larger and to act as a warning sign.

It has been shown that webs containing stabilimenta catch fewer insects because they are less cryptic, but on the other hand these webs are less often damaged by birds flying through them.

Conservation

Argiope trifasciata is listed as Least Concern by the South African National Biodiversity Institute due to its wide global distribution. The species is protected in 14 protected areas including Roodeplaatdam Nature Reserve, Ndumo Game Reserve, and Lekgalameetse Nature Reserve.

Taxonomy

The species was originally described by Forsskål in 1775 as Aranea trifasciata. It was revised by Bjørn in 1997. Levi synonymized numerous species with A. trifasciata including A. abalosi, A. avara, A. seminola, A. stenogastra, A. pradhani and Brachygea platycephala.

Subspecies

• Argiope trifasciata deserticola Simon, 1906 (Sudan)
• Argiope trifasciata kauaiensis Simon, 1900 (Hawaii)

External links

• Citizen science observations for Argiope trifasciata at iNaturalist
• With images.
• Diagnostic photographs and descriptions: Argiope trifasciata Creative Commons Licensed