Host preference of a temperate mistletoe: Disproportional infection on three co-occurring host species influenced by differential success

Abstract

The mistletoe Tristerix verticillatus (Loranthaceae) parasitizes within a small area of the Yerba Loca Nature Sanctuary near Santiago, Chile, three co-occurring hosts: Schinus montanus (Anacardiaceae), Fabiana imbricata (Solanaceae) and Berberis montana (Berberidaceae). Previous studies suggest that T.verticillatus may be favoured when parasitizing S.montanus relative to the other two host species. We hypothesize that infection of S.montanus is not proportional to its local abundance or appearance, that S.montanus is more intensively parasitized than other available hosts, and that host provenance is a determinant of the fate of the infecting seed. We compare the incidence of infection of T.verticillatus in relation to local availability and appearance variables, and the intensity of infection of T.verticillatus, on the three co-occurring host species. We then test the effects of host provenance on mistletoe seed establishment success with a seed cross inoculation experiment varying th