FACTORS FACILITATING SYNERGISTIC PREDATION: THE CENTRAL ROLE OF SYNCHRONY

Abstract

Determining the phenological and diel concurrence of potentially overlapping predator guilds in a given system provides a gauge of the potential prevalence and importance of synergistic prey suppression. The phenology of pea aphids (Acyrthosiphon pisum) and ground- and foliar-foraging predators was determined through a combination of pitfall and sweep-net sampling in alfalfa. These results revealed diverse guilds of ground- and foliar-foraging predators with a high degree of phenological overlap among individual species. One of the most common ground-foraging predators, Harpalus pennsylvanicus, was found to be significantly more active at night, but also to maintain moderate activity levels during the day. When tested individually in simple arenas with full access to aphids, the aphid-consumption rates of five common ground-foraging predators (H. aeneus, H. pennsylvanicus, Amara familiaris, A. octopunctatum, and Philonthus spp.) were not significantly different from that of Coccinella septempunctata, a fo...