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

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

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 ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprisin ...

, the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

, and

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

. The similar looking '' Argiope bruennichi'' is common in the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

. 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.

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 spider silk, silk structure included in the webs of some species of Spider web#Types of spider webs, orb-web spider. Its function is a subject of debate. O ...

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 wasp Paper wasps are a type of Eusociality, social vespid wasps. The term is typically used to refer to members of the Vespidae, vespid subfamily Polistinae, though it often colloquially includes members of the subfamilies Vespinae (hornets and yel ...

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 traffic ...

. It has been shown that webs containing

catch fewer insects because they are less cryptic, but on the other hand these webs are less often damaged by birds flying through them.

Gallery

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