Carnivorous pitcher plants eat a diet of certain spiders, regardless of what's on the menu

摘要

The purple pitcher plant, Sarracenia purpurea , is a low‐lying carnivorous plant that uses pitcher‐shaped leaves to catch arthropod prey for nutrition. Spiders make up a significant portion of these prey. To determine the tendency of specific spider taxa to be captured by the plant, we compared the composition (by taxonomic family) of three spider assemblages: those captured by the plant, those residing on or over the plant, and those found nearby in the local environment. Although there were some broad similarities within the three spider assemblages, significant differences existed when specific families and guilds were considered. While some families (e.g., Linyphiidae and Lycosidae) and guilds (e.g., low sheet/tangle weavers) were heavily represented in all three assemblages, other groups varied, and we found that the taxonomic makeup of victimized and resident spiders did not always reflect their environmental abundances. Moreover, spider assemblages captured by S.?purpurea were extremely similar across distant locations regardless of environmental spider assemblage composition, suggesting that S.?purpurea is very selective in its spider capture regimen.