Web-building spiders (e.g. _Frontinella communis_ and _Neriene radiata_) and northern pitcher plants (_Sarracenia purpurea_) are co-occurring sit-and-wait predators that may compete for shared arthropod prey. We evaluated prey availability and capture rates by web-weaving spiders and pitcher plants in a headwater stream box complex (Harvard Pond) in central Massachusetts. We established 40 plots with spider and pitcher plant removal treatments, and collected arthropod prey captured by open pitcher plants, pitfall traps, and sticky traps in those plots. 

The removal of web-building spiders significantly changed the distribution of prey captured by the pitcher plants (Chi-square test: P = 2.2 × 10-16 at Harvard... |