Banded Argiope (Argiope trifasciata) - female

''Argiope trifasciata'' (the banded garden spider or banded orb weaving spider) is a species of

spider Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species d ...

native to North and South America, but now found around the world. It can be found in certain areas of Europe, namely the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...

, the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Mo ...

, and

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

. The similar looking ''

Argiope bruennichi ''Argiope bruennichi'' (wasp spider) is a species of orb-web spider distributed throughout central Europe, northern Europe, north Africa, parts of Asia, and the Azores archipelago. Like many other members of the genus '' Argiope'' (including St ...

'' is common in the

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.''Argiope bruennichi'' at the Azorean Biodiversity Portal
/ref> They typically begin to appear during autumn from early September to late October as temperatures start dropping. 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.

Behavior

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 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 A stabilimentum (plural: stabilimenta), also known as a web decoration, is a conspicuous silk structure included in the webs of some species of orb-web spider. Its function is a subject of debate. Origin It is likely that the use of stabiliment ...

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 Diurnal ("daily") may refer to: General * Diurnal cycle, any pattern that recurs daily ** Diurnality, the behavior of animals and plants that are active in the daytime * Diurnal phase shift, a phase shift of electromagnetic signals * Diurnal tem ...

, and feeds on the insects that get snared in the web. Large, powerful prey like

paper wasp Paper wasps are vespid wasps that gather fibers from dead wood and plant stems, which they mix with saliva, and use to construct nests made of gray or brown papery material. Some types of paper wasps are also sometimes called umbrella wasps, ...

s, are swiftly wrapped in silk to immobilise them, before being injected with toxic saliva.

Subspecies

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

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 A warning sign is a type of sign which indicates a potential hazard, obstacle, or condition requiring special attention. Some are traffic signs that indicate hazards on roads that may not be readily apparent to a driver. While warning traffi ...

. It has been shown that webs containing

catch fewer insects because they are less

cryptic Cryptic may refer to: In science: * Cryptic species complex, a group of species that are very difficult to distinguish from one another * Crypsis, the ability of animals to blend in to avoid observation * Cryptic era, earliest period of the Earth ...

, but on the other hand these webs are less often damaged by birds flying through them.

References

External links

* With images.
Diagnostic photographs and descriptions: ''Argiope trifasciata''
Creative Commons Licensed {{Taxonbar , from=Q2706883 trifasciata Spiders described in 1775 Spiders of North America Spiders of South America Taxa named by Peter Forsskål