Community-wide responses to predation risk: Effects of predator hunting mode on herbivores, pollinators, and parasitoids

Abstract

1. Flower visitation by herbivores and pollinators often occurs simultaneously, but their potential contrasting responses to predation risk are rarely investigated in concert. Predator avoidance behaviour is common in pollinators, but remarkably little is known about the responses of other flower visitors, such as herbivores and parasitoids, to predation risk. Several traits of predators and prey are important to the overall impact of predation risk in insect communities, but how predator hunting mode influences distinct feeding guilds is not well understood. 2. This study evaluated the effects of predation risk by non-lethal predators with distinct hunting modes, a sit-and-wait crab spider and an actively hunting lynx spider, on floral visitation by herbivores, pollinators and parasitoids. 3. Non-lethal spiders drastically reduced flower visitation by herbivores and parasitoids. Pollinator responses to predation risk were taxon-specific. Non-lethal spiders did not affect specialist pollinators. In contrast, generalist pollinators avoided plants with sit-and-wait non-lethal crab spiders. 4. These results suggest that predator avoidance behaviour depends on predator and prey traits. Therefore, a community-wide approach to predation risk effects should be considered, particularly in systems where different guilds are present.