About Argiope appensa (Walckenaer, 1841)
This species exhibits clear sexual dimorphism. Females, which have a striking black and yellow coloration, measure 5.1–6.4 cm (2–2.5 inches) in total length including legs. Males are brown and only reach approximately 1.9 cm (0.75 inches) in total length. On Guam, where Argiope appensa is extremely widespread, the kleptoparasitic spider Argyrodes argentatus frequently visits its webs to steal leftover uneaten prey. Following the introduction of the brown tree snake to Guam, many of the island's small bird species went extinct or nearly extinct. This caused a decrease in predation and competition for Argiope appensa, and as a result, local spider populations increased dramatically. Nature writer David Quammen described Argiope appensa as almost certainly one of the larger species encountered on Guam, where he found it present in vast numbers during a research trip for his book The Song of the Dodo. Argiope appensa is distributed across multiple islands in the western Pacific Ocean. Its native range includes Hawaii, Taiwan, Australia, New Caledonia, New Guinea, and Indonesia. It has been introduced to all of Hawaii's main islands. It can live in a broad range of habitat types, ranging from coastal areas to upland forests. During the rainy season, which runs from June to November, this species is particularly common in open sunny edge locations such as roadsides and cultivated areas.
