Grace Lynch

Tall goldenrod (Solidago altissima) is native United States aster often used in studies of plant ecology and insect behavior. In past studies, the response of goldenrod to herbivory has suggested that resource allocation could be based on levels and consistency of herbivory, as well as the desire to produce more flowers which are strongly correlated to pollinator abundance. This study covers the interactions between herbivory and pollination as they relate to flower mass for ten genotypes of native Duluth goldenrod. Indicators of growth (number of leaves, height, flower area), herbivory (total leaf damage, galls, number of aphids), and stress (senescing leaves) were measured for 10 replicates of each native Duluth genotype . Over a three-month period, total pollinators were recorded for each plant on 12 sampling dates, followed by a measurement of final flower area. Statistical analysis of the factors involved in flower quantity and total number of pollinators found that 59.1% of the variation in quantity of flowers per plant was explained by interactions between the genotype of the plant, the number of galls on the plant, and the plant height. Contrary to expectation, 61.8% of the variation in number of pollinators attracted to an individual plant was explained by interactions between flower quantity, genotype, herbivory from gall-makers, lace bugs, and aphids, and plant stress. These results introduce a new component of flower ‘quality’ which incorporates a much larger range of variables than anticipated.