Biological control agents introduced into the U.S. for the control of invasive hydrilla have been partially effective and new agents are needed, especially those adapted to cooler climates and environments. Since 2014, extensive surveys of hydrilla have been conducted in Asia, particularly China and the Republic of Korea, where the U.S. introductions were thought to have originated. Samples were genetically characterized to identify matches with the three invasive U.S. introductions; separate dioecious and monoecious introductions last century and the more recent detection in the Connecticut River. Sites have been identified where each of these three distinct genotypes occur and include both monoecious and dioecious biotypes. Surveys have been conducted at these sites to identify and collect herbivores to be evaluated as biological control agents. Matt Purcell, Director of the USDA ARS Australian Biological Control Laboratory, will provide an overview of those survey efforts and will discuss several insect species that are being evaluated to determine their potential effectiveness as biological control agents for U.S. invasive hydrilla.