Larvae of Nymphulinae (Lepidoptera : Pyralidae) associated with Hydrilla verticillata (Hydrocharitaceae) in North Queensland

Australian Nymphulinae are a diverse group of moths with aquatic caterpillars that probably play an important role in determining the composition and abundance of aquatic macrophytes in Australian freshwater systems. Less than 10% of the nymphuline larvae in Australia have been described. As part of a project to develop biological control agents for hydrilla, Hydrilla verticillata, we encountered a variety of Nymphulinae larvae feeding on this and other aquatic plants. We illustrate, describe and provide a key to five species of Nymphulinae larvae (Ambia ptolycusalis (Walker), Parapoynx diminutalis Snellen, Hygraula nitens Butler, Margarosticha repititalis (Warren) and Theila siennata (Warren)) that feed on hydrilla in North Queensland. Information on their host plants also is included. Our field research indicates that none of these species should be considered as potential biological control agents for hydrilla.