Many studies have addressed several plant-insect interaction topics at nutritional, molecular, physiological, and evolutionary levels. However, it is still unknown how flexible the metabolism and the nutritional content of specialist insect herbivores feeding on different closely related plants can be. We performed elemental, stoichiometric, and metabolomics analyses on leaves of two coexisting Pinus sylvestris subspecies and on their main insect herbivore; the caterpillar of the processionary moth (Thaumetopoea pityocampa). Caterpillars feeding on different pine subspecies had distinct overall metabolome structure, accounting for over 10% of the total variability. Although plants and insects have very divergent metabolomes, caterpillars showed certain resemblance to their plant-host metabolome. In addition, few plant-related secondary metabolites were found accumulated in caterpillar tissues which could potentially be used for self-defense. Caterpillars feeding on N and P richer needles had lower N and P tissue concentration and higher C:N and C:P ratios, suggesting that nutrient transfer is not necessarily linear through trophic levels and other plant-metabolic factors could be interfering. This exploratory study showed that little chemical differences between plant food sources can impact the overall metabolome of specialist insect herbivores. Significant nutritional shifts in herbivore tissues could lead to larger changes of the trophic web structure.

• Klíčová slova
• herbivory, metabolomics, plant-insect, processionary moth, scots pine, secondary metabolites, stoichiometry,
• MeSH
• analýza hlavních komponent MeSH
• borovice lesní metabolismus   parazitologie   MeSH
• býložravci MeSH
• druhová specificita MeSH
• dusík analýza   MeSH
• fosfor analýza   MeSH
• hmotnostní spektrometrie MeSH
• interakce hostitele a parazita MeSH
• larva chemie   fyziologie   MeSH
• listy rostlin chemie   metabolismus   parazitologie   MeSH
• metabolom * MeSH
• metabolomika * MeSH
• můry růst a vývoj   fyziologie   MeSH
• stravovací zvyklosti MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusík MeSH
• fosfor MeSH

At the molecular level, folivory activity on plants has mainly been related to the foliar concentrations of nitrogen (N) and/or particular metabolites. We studied the responses of different nutrients and the whole metabolome of Quercus ilex to seasonal changes and to moderate field experimental conditions of drought, and how this drought may affect folivory activity, using stoichiometric and metabolomic techniques. Foliar potassium (K) concentrations increased in summer and consequently led to higher foliar K : phosphorus (P) and lower carbon (C) : K and N : K ratios. Foliar N : P ratios were not lowest in spring as expected by the growth rate hypothesis. Trees exposed to moderate drought presented higher concentrations of total sugars and phenolics and these trees also experienced more severe folivory attack. The foliar increases in K, sugars and antioxidant concentrations in summer, the driest Mediterranean season, indicated enhanced osmoprotection under natural drought conditions. Trees under moderate drought also presented higher concentrations of sugars and phenolics; a plant response to avoid water loss. These shifts in metabolism produced an indirect relationship between increased drought and folivory activity.

• Klíčová slova
• drought, ecology, ecometabolomics, folivory, metabolomics, stoichiometry,
• MeSH
• aminokyseliny metabolismus   MeSH
• analýza hlavních komponent MeSH
• biologické modely MeSH
• býložravci fyziologie   MeSH
• diskriminační analýza MeSH
• dub (rod) fyziologie   MeSH
• listy rostlin metabolismus   MeSH
• metabolismus sacharidů MeSH
• metabolom * MeSH
• metabolomika MeSH
• metoda nejmenších čtverců MeSH
• období sucha * MeSH
• polyfenoly metabolismus   MeSH
• roční období MeSH
• stromy fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Španělsko MeSH
• Názvy látek
• aminokyseliny MeSH
• polyfenoly MeSH