Swamp Loosestrife

The flowers are cross-pollinated by honeybees, bumblebees, Swallowtail butterflies, and probably other insects. These visitors obtain primarily nectar from the flowers. The caterpillars of Darapsa versicolor (Hydrangea Sphinx) and Eudryas unio (Pearly Wood Nymph) feed on the foliage, while the caterpillars of Papaipema cataphracta (Burdock Borer Moth) and Papaipema sulphurata (Decodon Borer Moth) bore through the stems. The range of the rare Decodon Borer Moth is restricted to northeastern United States. The seed capsules of Swamp Loosestrife are eaten by several ducks: the Mallard, Black Duck, Blue-Winged Teal, Green-Winged Teal, and Wood Duck. Muskrats like to feed on the swollen and spongy underwater stems.