U.S. Army Engineer Research and Development Center, Environmental Laboratory Vicksburg United States
This report summarizes the result of 2013 surveys in the Peoples Republic of China of the invasive aquatic weed Hydrilla verticillata for potential insect biological control agents. Plants were examined at 34 sites throughout eastern China, resulting in the collection of leaf-mining Hydrellia spp. Diptera Ephydridae, Parapoynx diminutalis Lepidoptera Crambidae, various Chironomidae Diptera, Macroplea japonica Coleoptera Chrysomelidae, and other unidentified insect herbivores. Additionally, effort was made to identify plants as monoecious or dioecious, since both biotypes are present in the US. However, at the majority of sites only dioecious plants were apparent. Previous surveys in China were limited in scope and never included biotype identification consequently, the present work represents an initial attempt to locate biotype-matched hydrilla biological control agents for use in the US. An Appendix with site locations and descriptions is included.