Web-Construction Behavior of Linyphiid Spiders (Araneae, Linyphiidae): Competition and Co-Existence Within a Generalist Predator Guild

The web-construction behavior of three species of linyphiid spider (Erigone autumnalis, Meioneta unimaculata and Bathyphantes pallida) was studied in the laboratory to examine competition and co-existence within predator guilds. Competitive interactions between spiders potentially reduce their role in biological control. We tested the hypothesis that at high densities, intraguild competition for web-sites would occur but spatial separation of microhabitat would reduce interguild competition, thus allowing co-existence. High mortality and reduced web-size were observed at high B. pallida densities but Linyphiinae co-existed with Erigoninae which constructed webs at different strata. Competitive exclusion by larger individuals occurred between species whose microhabitat niche overlapped. The biocontrol potential of spider or arthropod predator guilds could ultimately be enhanced by maximizing the diversity of species whose niche axes vary.