Oviposition by herbivorous insects induces changes in optical and mechanical properties of Prunus avium leaves

Abstract

This study of animal–plant interaction focused on the impact of oviposition by an insect on the leaves of Prunus avium (cherries). We examined whether the oviposition by Caliroa cerasi affects leaf mechanical and spectral traits in P. avium. Three cultivars of P. avium were studied. Infested leaves had from 1 to 18 eggs and exhibited higher leaf dry mass per area (LMA) than leaves without eggs. Leaf dry weight and LMA were positively correlated with egg number per leaf. Infested leaves tended to have higher number of trichomes. Leaf thickness and material and structural resistance tended to increase in infested leaves. The reflectance across all wavelengths (500–700 nm) in leaves with larger number of eggs was higher compared to leaves without eggs. Photosynthetic performance was reduced and oxidative activity was increased in leaves with eggs. Extrafloral nectaries increased with increasing the number of eggs per leaf and thus play an important role in defense against herbivores by providing nectar rewards that attract their depredators. These responses to oviposition may be beneficial for the plants in terms of resistance to feeding larvae.