Ein Beitrag zur Phänologie von Larinioides sclopetarius (Araneae: Araneidae)

Abstract

A contribution towards the phenology of Larinioides sclopetarius (Clerck, 1757) (Araneae: Ara- neidae). We investigated a colony of Larinioides sclopetarius, the bridge spider, situated at a bridge-like dam in the city of Duisburg, Germany. The study ran from March until October 2004. The mean population density (all size classes) was 26.2 ind./m². The absolute maximum was found in July (71.3 ind./m²). Most of the spiderlings were found from June to October with mean densities up to 30.9 ind./m² in July, indicating that breeding of L. sclopetarius started in summer. Adult males and females occurred in spring, although the highest abundances (up to more than 3 individuals of each sex per m²) were found in summer and autumn. The adult sex ratio averaged over the study period was 1:1.2 (??:??). Some comparisons with other araneids, both solitary and social species, are drawn and discussed.