RT article T1 Pre-adaptive shift of a native predator (Araneae, Zodariidae) to an abundant invasive ant species (Hymenoptera, Formicidae) A1 Monzó, César A1 Juan-Blasco, Maria A1 Pekar, Stano A1 Molla, Oscar A1 Castanera, Pedro A1 Urbaneja, Alberto AB Invasive species often displace native species and can affect ecological processes in invaded habitats. If invasive species become abundant, changes in prey availability may be particularly harmful to specialist predators. The Argentine ant, Linepithema humile Mayr, is an important invasive species on nearly all continents. Spiders of the genus Zodarion are specialised ant-eating predators native to the Mediterranean yet it is unknown if they can exploit invasive ant species. Here we studied spatial and temporal abundance of this invasive ant and the native spider, Zodarion cesari Pekar, during 4 years in four citrus groves. Circadian activity of both spiders and ants, and capture efficiency and prey specificity of the predator were also evaluated. The abundance of Z. cesari was strongly correlated to L. humile abundance. The predatory activity of spiders varied seasonally with differences on the relative frequency of spiders capturing ants depending on the time of the year. In laboratory, Z. cesari displayed most efficient capture upon the native ant Tapinoma nigerrimum (Nylander) and the invasive ant L. humile in comparison with five other native ant species. These results demonstrate that the native spider Z. cesari is successfully exploiting the invasive ant species L. humile and is likely a locally monophagous predator. We suggest that Z. cesari shifted away from native T. nigerrimum post invasion as both ant species are phylogenetically related and of similar size. SN 1387-3547 YR 2013 FD 2013 LK http://hdl.handle.net/20.500.11939/5682 UL http://hdl.handle.net/20.500.11939/5682 LA en NO Monzo, Cesar, J.-Blasco, M., Pekar, Stano, Molla, O., Castanera, P., Urbaneja, A. (2013). Pre-adaptive shift of a native predator (Araneae, Zodariidae), to an abundant invasive ant species (Hymenoptera, Formicidae). Biological Invasions, 15(1), 89-100. DS MINDS@UW RD Jan 17, 2021