TY - JOUR T1 - Search for top-down and bottom-up drivers of latitudinal trends in insect herbivory in oak trees in Europe JF - bioRxiv DO - 10.1101/2020.02.25.964213 SP - 2020.02.25.964213 AU - Elena Valdés-Correcher AU - Xoaquín Moreira AU - Laurent Augusto AU - Luc Barbaro AU - Christophe Bouget AU - Olivier Bouriaud AU - Manuela Branco AU - Giada Centenaro AU - György Csóka AU - Thomas Damestoy AU - Jovan Dobrosavljević AU - Mihai-Leonard Duduman AU - Anne-Maïmiti Dulaurent AU - Csaba B. Eötvös AU - Maria Faticov AU - Marco Ferrante AU - Ágnes Fürjes-Mikó AU - Andrea Galmán AU - Martin M. Gossner AU - Arndt Hampe AU - Deborah Harvey AU - Andrew Gordon Howe AU - Yasmine Kadiri AU - Michèle Kaennel-Dobbertin AU - Julia Koricheva AU - Alexander Kozel AU - Mikhail V. Kozlov AU - Gábor L. Löveï AU - Daniela Lupaştean AU - Slobodan Milanović AU - Anna Mrazova AU - Lars Opgennoorth AU - Juha-Matti Pitkänen AU - Anna Popova AU - Marija Popović AU - Andreas Prinzing AU - Valentin Queloz AU - Tomas Roslin AU - Aurélien Sallé AU - Katerina Sam AU - Michael Scherer-Lorenzen AU - Andreas Schuldt AU - Andrey Selikhovkin AU - Lassi Suominen AU - Ayco J. M. Tack AU - Marketa Tahadlova AU - Rebecca Thomas AU - Bastien Castagneyrol Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/02/26/2020.02.25.964213.abstract N2 - Aim The strength of species interactions is traditionally expected to become stronger toward the Equator. However, recent studies have reported opposite or inconsistent latitudinal trends in the bottom-up (plant quality) and top-down (natural enemies) forces driving insect herbivory, possibly because these forces have rarely been studied concomitantly. This makes previous attempts to understand the effect of large scale climatic gradients on insect herbivory unsuccessful.Location EuropeTime period 2018-2019Major taxa studied Quercus roburMethods We used scholar-based citizen science to simultaneously test for latitudinal variation in plant-herbivore-natural enemy interactions. We further investigated the underlying climatic factors associated with variation in herbivory, leaf chemistry and attack rates in Quercus robur across its complete latitudinal range in Europe. We quantified insect herbivory and the occurrence of specialist herbivores as well as leaf chemistry and bird attack rates on dummy caterpillars on 261 oak trees.Results Climatic factors rather than latitude per se were the best predictors of the large-scale (geographical) variation in the incidence of gall-inducers and leaf-miners as well as of leaf nutritional quality. However, insect herbivory, plant chemical defences (leaf phenolics) and bird attack rates were not influenced by latitude or climatic factors. The incidence of leaf-miners increased with increasing concentrations of hydrolysable tannins and decreased with those of condensed tannins, whereas the incidence of gall-inducers increased with increasing leaf soluble sugar concentration and decreased with increasing leaf C:N ratios. However, neither other traits nor bird attack rates varied with insect herbivory.Main conclusions These findings help to refine our understanding of the bottom-up and top-down mechanisms driving geographical variation in plant-herbivore interactions, and urge for further examination of the drivers of insect herbivory on trees. ER -