During their annual growth cycle, plants are often subjected to leaf area loss due to arthropod feeding, potentially limiting growth and reproduction. However, the detrimental effects of foliar herbivory may be attenuated by plant compensatory responses to foliar damage. In this study, the effect of phenophase (physiological stage of development) on the vine’s compensatory abilities was investigated in terms of source-sink relationships. Twenty percent of all fully expanded leaves of 1 year old fruitless grape vines, Vitis labrusca var. ‘Niagara’, were mechanically damaged during bloom, during veraison (berry ripening), or during bloom and veraison. In addition, another set of vines was damaged early in the season (pea sized berry) and late in the season (veraison) utilizing two naturally occurring foliar herbivores; the rose chafer, Macrodactylus subspinosus , and the Japanese beetle, Popillia japonica, respectively. Fruit bearing vines were used to mark the physiological stages of development. Throughout the season growth parameters, leaf photosynthetic capacity, and whole vine photosynthetic capacity were measured on both sets of vines. To determine the relative response of vines to mechanical damage and foliar herbivory by these two beetles, single leaves were damaged during bloom using M. subspinosus and during veraison using P. japonica, with the damage levels duplicated mechanically on separate vines. Photosynthetic measurements were taken of undamaged and damaged tissue on these leaves, up to 14 days after damage to determine and compare leaf photosynthetic response to beetle and mechanical damage.
Species 1: Coleoptera Scarabaeidae Macrodactylus subspinosus (rose chafer)
Species 2: Coleoptera Scarabaeidae Popillia japonica (Japanese beetle)
Species 3: Rhamnales Vitaceae Vitis labrusca (juice grape var. 'Niagara')
Keywords: compensation, herbivory
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA