Decreased web investment in sub-tropical Nephila clavata (Tetragnathidae)

Abstract

Webs of Nephila clavata living in Okinawa, a sub-tropical region of Japan, were found to be significantly smaller and to have less number of radii and spirals than those seen in temperate Tokyo. According to recent papers, a web is thought to get smaller when prey is abundant (Sherman 1994), or before molting and egg-laying (Higgins 1990), but none of these explain web reduction in Okinawa. We propose an alternative explanation: the necessity of the spider to adjust its life cycle to a sub-tropical climate.