Ecology, 96(11), 2015, pp. 2902–2911 Ó 2015 by the Ecological Society of America Varying predator personalities generates contrasting prey communities in an agroecosystem RAPHAE ¨ L ROYAUTE ´ 1,3 AND JONATHAN N. PRUITT 2 1 Department of Biological Sciences, North Dakota State University, Fargo, North Dakota 58102 USA 2 Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 USA Abstract. Most taxa show consistent individual differences in behavior, a phenomenon often referred to as animal ‘‘personalities.’’ While the links between individual personality and fitness have received considerable attention, little information is available on how animal personality impacts higher-order ecological processes, such as community dynamics. Using a mesocosm experiment, we subjected a representative community of alfalfa pests to different compositions of personality types of the wolf spider Pardosa milvina. We show that subtle variation in the personality composition of P. milvina populations generate wildly different prey communities, where a mixture of both active and sedentary individuals performs best at suppressing prey abundance. Our results provide the first experimental evidence that predator personality types can generate contrasting prey communities. Moreover, our results suggest that manipulating the representation of predator personality types may be a profitable avenue by which one can maximize the biocontrol potential of predator populations. Key words: arthropod generalist predators; behavioral type 3 behavioral type interactions; biocontrol; Lycosidae; personality; pests community dynamics; predator–prey dynamics. INTRODUCTION Animal personality (also referred to as ‘‘tempera- ment’’ or ‘‘behavioral syndromes’’) is a field of study devoted to understanding the drivers and consequences of consistent individual differences in behavior. Within virtually any population, some individuals are consis- tently more active, more aggressive, or are more willing to engage in risk-taking behavior (Sih et al. 2004a, b, Re´ ale et al. 2007). Such personality differences are an important determinant of an individual’s fitness (Dinge- manse et al. 2004, Dingemanse and Re´ale 2005). These individual differences have also been associated with various underlying physiological and genetic mecha- nisms (Careau et al. 2008, Bell and Aubin-Horth 2010, Norton et al. 2011) and often exhibit a significant heritability (Stirling et al. 2002). In addition, personality differences have the potential to influence larger ecological and evolutionary processes (Sih et al. 2012, Wolf and Weissing 2012), including invasion success, metapopulation dynamics, succession, species interac- tions, and even extinction risk. In this manuscript, we will refer to separate classes or categories of personalities as behavioral types or personality types interchangeably. The ecological consequences of animal personality have been considered most rigorously in the context of predator–prey interactions. Dozens of studies from a wide variety of systems have demonstrated, for instance, that prey personalities can influence prey growth rate (reviewed in Stamps 2007), susceptibility to predation (Bell and Sih 2007), and the intensity of trait-mediated species interactions (Griffen et al. 2012, Toscano and Griffen 2014). Other studies have shown that predator personality types can influence predator feeding rate, diet breadth, and the kinds of prey that individuals tend to encounter and consume (Riechert and Hedrick 1993, Matich et al. 2011; reviewed in Arau´jo et al. 2011). Still other studies have shown that the outcome of predator– prey interactions depend on subtle differences in the representation of different personality types in both predator and prey populations, hence the performance of either predator or prey depends on the strategies present in the opposing trophic level (Pruitt et al. 2012, DiRienzo et al. 2013, McGhee et al. 2013, Sweeney et al. 2013). This last scenario is referred to as behavioral type 3 behavioral type interactions, and implies that no one strategy in either predator or prey consistently experi- ences superior performance. Yet, such interactions have mostly been studied in the context of single-predator– single-prey-species experiments and are therefore limited in their ability to inform how predator personality influences community dynamics. A useful framework for predicting the community- level consequences of behavioral type 3 behavioral type interactions stems from the classic literature on foraging mode. Huey and Pianka (1981) argued that the kinds of prey consumed by predators would be different and predictable depending on predators’ foraging mode: sedentary predators should tend to catch active roving prey whereas active predators would tend to capture sedentary prey. Although the locomotor crossover Manuscript received 17 December 2014; revised 2 April 2015; accepted 7 May 2015. Corresponding Editor: W. E. Snyder. 3 E-mail: raphael.royaute@gmail.com 2902