XVI International Botanical Congess

Purple loosestrife (Lythrum salicaria L.) is a Euarasian perennial which is becoming naturalized in North American waterways and is displacing indigenous flora. One biological control measure has been the introduction of the leaf-feeding beetle Galerucella calmariensis. We grew 26 purple loosestrife plants in the greenhouse and introduced varying densities of G. calmariensis beetles. Leaf area, root starch concentrations and second year growth characteristics were measured in the plants. Reduction in purple loosestrife leaf area was positively related to beetle density, however initial second year growth was not highly related to beetle density. Further results will be presented. This research was partially supported by NSF, Division of Undergraduate Education, ILI-IP grant DUE-9751176.