Caerostris darwini

About

Caerostris darwini, commonly known as Darwin's bark spider, is an orb-weaver spider renowned for its remarkable web-spinning abilities. Native to Madagascar, this species was discovered in the Andasibe-Mantadia National Park in 2009. It produces the largest known orb webs, with sizes ranging from 900 to 28,000 square centimeters and bridge lines spanning up to 25 meters[1][2]. The spider's silk is exceptionally strong and tough, making it one of the most impressive biological materials studied[1][3]. Darwin's bark spider exhibits extreme sexual dimorphism, with females being significantly larger than males. Females have a body length of about 18 to 22 mm, while males are approximately 6 mm long[1][5]. The spider's web architecture is notable for its "hub-and-spoke" design, allowing efficient movement and prey capture[2]. The species is named in honor of Charles Darwin and is currently listed as "least concern" by the IUCN, though its habitat is threatened by deforestation[2]. Its ecological role is significant, helping regulate insect populations in its ecosystem[2].