2001; Faeth and Saikkonen 2007), (3) the number of non-toxic endophyte-infected grasses exceed toxic ones (Faeth 2002), and (4) in some cases, infection decreased, rather than increased, the herbivore resistance of the host plant (Faeth and Shochat 2010; Jani et al. 2010; Saikkonen et al. 1998; Schulthess and Faeth 1998). Altough well-studied in agronomic cultivars such as K-31 in introduced areas, the interactions between tall fescue and Neotyphodium endophytes are still largely ignored in their native range in Europe (Saari et al. 2010; Zabalgogeazcoa and Bony 2005), probably because

tall fescue is not a preferred livestock forage grass (Niemeläinen et al. 2001) and livestock toxicosis is rare (Zabalgogeazcoa and Bony 2005). The 4SC-202 solubility dmso nature and ecological APR-246 mw importance of the tall fescue–N. coenophialum symbiosis may be different in its native range (Saikkonen 2000; Saikkonen et al. 1998; Siegel and Bush 1996). We examined whether the N. coenophialum

endophyte infection and the origin of the host plant as well as abiotic factors and their possible interactions affect the invertebrate community living on tall fescue. Besides herbivores, fungal endophytes may also affect detritivores (e.g., Lemons et al. 2005) and the natural enemies of herbivores (Faeth and Shochat 2010; Hartley and Gange 2009; Jani et al. 2010; Omacini et al. 2001) or render herbivores more or less susceptible to natural enemies by affecting their attack rates (Benrey and Denno 1997; Saari et al. 2010) and delaying herbivore development (e.g. Breen 1994; Clay et al. 1985; Popay and Rowan 1994). However, there are only a few studies that have considered the impact of grass endophytes on arthropod communities or functional groups (e.g., Afkhami and Rudgers 2009; Faeth and Shochat 2010; Jani et al. 2010). In this study, we used a ID-8 whole-invertebrate

community survey of a controlled common garden experiment to test how invertebrate diversity and community structure, and the number of individuals in functional invertebrate taxa and guilds differs between (i) endophyte infected (E+), endophyte free (E-), and manipulatively endophyte-free (ME-) tall fescue, (ii) host plants of different origin (wild populations from Åland, Gotland, coastal Sweden and one agronomical cultivar, K-31 from USA), and (iii) host plants growing in different abiotic environments (nutrient and water treatments). Based on the past studies on defensive endophyte-grass mutualism (Saikkonen et al.