Argiope appensa

This species occurs on several islands in the western Pacific Ocean, in Hawaii and from Taiwan, Australia, New Caledonia, New Guinea to Indonesia.[1]

It has been introduced to all main islands of Hawaii. It inhabits a wide variety of habitats, from coasts to upland forests.[2] During the rainy season from June to November, this species is common in sunny edge areas, such as along roadsides and cultivated area.[3]

This species shows an evident sexual dimorphism. The strikingly black and yellow females are 5.1–6.4 cm (2–2.5 in) long, including legs, while the brown males reach only about 1.9 cm (0.75 in).[2]

In Hawaii they are referred to as Hawaiian garden spiders.[4] In Hawaii, they are known to be quite communal (see picture), with multi-generational specimens living within close quarters, using the same anchor lines for separate webs.

On Guam, where Argiope appensa is ubiquitous, it is frequently visited by Argyrodes argentatus, that steals food from the host.[5] Locals there refer to them as banana spiders. Following the introduction of the brown tree snake and the subsequent extinction or near-extinction of many of the island's small birds, spider populations on Guam exploded in response to decreasing predation and competition. Nature writer David Quammen has called Argiope appensa "almost certainly one of the larger species" which were encountered in vast numbers during his research trip to Guam for the book The Song of the Dodo.

Argiope appensa construct webs mainly in bushes, between branches, and in human constructions. The webs are rather large and show a white zig-zag silk decoration developed from one corner to the center of the web.[2] These decorations, usually called stabilimenta, could be a warning device to prevent birds from inadvertently destroying the web.[3]

• 
  Community of multi-generational Argiope appensa on the Big Island of Hawaii
• 
  Mature female being handled in Hilo, Hawaii
• 
  Mature female (ventral view) and male (dorsal)
• 
  Side view of female
• 
  Female in Kuaui Jungle, Hawaii

Wikispecies has information related to Argiope appensa.

Wikimedia Commons has media related to Argiope appensa.

• Walckenaer, C. A. (1842): Histoire naturelle des Insects. Aptères. Paris, 2: 1-549.