We Are What We Eat: A Stoichiometric and Ecometabolomic Study of Caterpillars Feeding on Two Pine Subspecies of Pinus sylvestris
MetadataShow full item record
Plant-insectMetabolomicsProcessionary mothScots pineSecondary metabolitesHerbivory
Rivas-Ubach, A., Peñuelas, J., Hódar, J. A., Oravec, M., Paša-Tolić, L., Urban, O., & Sardans, J. (2019). We Are What We Eat: A Stoichiometric and Ecometabolomic Study of Caterpillars Feeding on Two Pine Subspecies of Pinus sylvestris. International journal of molecular sciences, 20(1), 59.
SponsorshipThis research was funded by the research fellowship (JAE) from the CSIC (A.R.-U), the European Research Council Synergy grant SyG-2013-610028 IMBALANCE-P (J.P., J.S.), the Spanish Government projects CGL2016-48074-P and OAPN 022/2008 (PROPINOL) (J.P., J.S.), the Catalan Government project SGR 2014-274 (J.P., J.S.), DOE Office of Science User Facility sponsored by the Office of Biological and Environmental Research at the Pacific Northwest National Laboratory (A.R.-U), and by the Ministry of Education, Youth and Sports of the Czech Republic (grant No. CZ.02.1.01/0.0/0.0/16_013/0001609, and No. LO1415) (O.U., M.O).
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.