The Importance of Pitcher Size in Prey Capture in the Carnivorous Plant, Sarracenia alata Wood (Sarraceniaceae)

Abstract

Prey capture in pitcher plants has been found to be significantly dependent on pitcher size, but the actual importance of size is not clearly understood. We studied insect capture by the carnivorous plant Sarracenia alata and compared the rate of insect capture per unit capture area of plants with that of nonbiological models and traps. The total mass of insects captured was significantly positively related to capture area for both biological and nonbiological systems. However, the rate of insect capture was significantly greater for plants than for models and traps, which suggests a role of attractants in insect capture in pitcher plants. Odor from decaying insects was found to have a significant effect on insect capture on experimental attraction cups. Further study should focus on the nature of other attractants including nectar, UV reflectance and volatiles to determine their role in insect capture by pitcher plants.