Carbon dioxide‐induced changes in beech foliage cause female beech weevil larvae to feed in a compensatory manner

The phenology of Fagus sylvatica was unaffected by exposure to an atmosphere of elevated CO2 (600 μL L‐1) after two years of fumigation. Non‐significant changes in nitrogen and phenolic content of the leaves decreased the nutritional status of beech for female larvae in elevated CO2 such that they responded by eating in a compensatory manner; males were unaffected. Rates of development, mortality and adult biomass of Rhynchaenus fagi were no different from those in ambient CO2 concentrations (355 μL L ‐1). It is possible that, with the changes in leaf chemistry affecting the females, fecundity will be altered, with important consequences for populations of beech weevil.