Differential attack on diploid, tetraploid, and hexaploid Solidago altissima L. by five insect gallmakers

• Published in: Oecologia 2008-01, Vol.154 (4), p.755-761
• Main Authors: Halverson, Kristy, Heard, Stephen B, Nason, John D, Stireman, John O. III
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Biomedical and Life Sciences; Community Ecology - Original Paper; Diploidy; Ecology; Ecosystem; Fundamental and applied biological sciences. Psychology; Genetic diversity; Genetic Variation; Goldenrod; Herbivores; Host-Parasite Interactions - genetics; Hydrology/Water Resources; Insect communities; Insect genetics; Insect-plant interactions; Insecta; Insecta - physiology; Insects; Invertebrates; Life Sciences; Midwestern United States; Phytophagous insects; Plant Sciences; Plant Tumors - genetics; Plant Tumors - parasitology; Plants; Ploidies; Polyploidy; Protozoa. Invertebrata; Solidago - genetics; Solidago - parasitology; Solidago altissima; Tetraploidy
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-007-0863-3

Genetic variation among plants can influence host choice and larval performance in insect herbivores. Ploidy (cytotype) variation is a particularly dramatic form of plant genetic variation, and where diploid and polyploid cytotypes of a species occur in sympatry, they may provide herbivores with choices that are distinguished by profound and genome-wide genetic differences. We tested for non-random attack by five gallmaking insect herbivores on diploid, tetraploid, and hexaploid cytotypes of the goldenrod Solidago altissima L., working in seven midwestern US populations where the ploidies co-occur on spatial scales relevant to insect host choice. For four of the five herbivores, attack was non-random with respect to ploidy at one or more sites. Ploidy effects on attack were complex: the ploidy subjected to highest attack varied both across herbivores within sites and (for most herbivores) across sites within herbivores. Ploidy effects on attack will alter rates of encounter between insect herbivores--either increasing or decreasing the likelihood of two herbivores sharing a host plant ramet, compared with the case with no effects of ploidy. Plant ploidy variation appears likely to have a major impact on insect community organization, and perhaps on plant-herbivore coevolution, but that impact is likely to be spatially heterogeneous.