title: Elm leaves 'warned' by insect egg deposition reduce survival of hatching larvae by a shift in their quantitative leaf metabolite pattern.
abstract: Plants may take insect eggs on their leaves as a warning of future herbivory and intensify their defence against feeding larvae. Responsible agents are, however, largely unknown, and little knowledge is available on this phenomenon in perennial plants. We investigated how egg deposition affects the anti-herbivore defence of elm against the multivoltine elm leaf beetle. Prior egg deposition caused changes in the quality of feeding-damaged leaves that resulted in increased larval mortality and reduced reproductive capacity of the herbivore by harming especially female larvae. Chemical analyses of primary and secondary leaf metabolites in feeding-damaged, egg-free (F) and feeding-damaged, egg-deposited (EF)-leaves revealed only small differences in concentrations when comparing metabolites singly. However, a pattern-focused analysis showed clearly separable patterns of (F) and (EF)-leaves because of concentration differences in especially nitrogen and phenolics, of which robinin was consumed in greater amounts by larvae on (EF) than on (F)-leaves. Our study shows that insect egg deposition mediates a shift in the quantitative nutritional pattern of feeding-damaged leaves, and thus might limit the herbivore's population growth by reducing the number of especially female herbivores. This may be a strategy that pays off in a long run particularly in perennial plants against multivoltine herbivores.
authors: Freie Universität Berlin, Dahlem Centre of Plant Sciences, Institute of Biology, Haderslebener Str. 9,, 12163, Berlin, Germany.|German Federal Institute for Risk Assessment (BfR), Department of Chemicals and Product Safety, Max-Dohrn-Str. 8-10,, 10589, Berlin, Germany.
authors: Nadine
authors: N
authors: Austel
authors: Freie Universität Berlin, Dahlem Centre of Plant Sciences, Institute of Biology, Haderslebener Str. 9,, 12163, Berlin, Germany.
authors: Elisabeth J
authors: EJ
authors: Eilers
authors: Freie Universität Berlin, Dahlem Centre of Plant Sciences, Institute of Biology, Haderslebener Str. 9,, 12163, Berlin, Germany.
authors: Torsten
authors: T
authors: Meiners
authors: Freie Universität Berlin, Dahlem Centre of Plant Sciences, Institute of Biology, Haderslebener Str. 9,, 12163, Berlin, Germany.
authors: Monika
authors: M
authors: Hilker
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D005260:Female; D005419:Flavonoids; D007814:Larva / Q000502:physiology; D055442:Metabolome; D055432:Metabolomics; D010058:Oviposition / Q000502:physiology*; D010063:Ovum / Q000502:physiology*; D010636:Phenols / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism* / Q000469:parasitology; D014197:Trees / Q000469:parasitology; D034403:Ulmus / Q000187:drug effects / Q000378:metabolism* / Q000469:parasitology*
chemical_list: D005419:Flavonoids; D010636:Phenols; C005183:robinin
keywords: Ulmus minor; Xanthogaleruca luteola; flavonoids; herbivory; nitrogen; perennial plant; phenolics; plant defence; quantitative nutritional pattern