Pritam Banerjee1, 2, Kathryn A. Stewart3, Caterina M. Antognazza4, Ingrid V. Bunholi5, Kristy Deiner6, Matthew A. Barnes7, Santanu Saha8, Héloïse Verdier9, Hideyuki Doi10, Jyoti Prakash Maity2, Michael W.Y. Chan1, Chien Yen Chen2*1Department of Biomedical Sciences, Graduate Institute of Molecular Biology, National Chung Cheng University, 168 University Road, Ming-Shung, Chiayi County 62102, Taiwan2Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Ming-Shung, Chiayi County 62102, Taiwan.3 Institute of Environmental Science, Leiden University, 2333 CC Leiden, The Netherlands4 Department of Theoretical and Applied Science, University of Insubria, Via J.H. Dunant, 3, 21100, Varese, Italy5 Department of Biology, Indiana State University, Terre Haute, IN 47809, USA6 Department of Environmental Systems Science, ETH Zurich, Universitätstrasse 16, CH-8092 Zurich, Switzerland7 Department of Natural Resources Management, Texas Tech University, Lubbock, TX USA8Post Graduate Department of Botany, Bidhannagar College, Salt Lake City, Kolkata 700064, India9Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Villeurbanne, France10Graduate School of Information Science, University of Hyogo, 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, JapanAbstract Plant-animal interactions (PAI) represent major channels of energy transfer through ecosystems, where both positive and negative relationships simultaneously contribute to ecosystem functioning. Extinction of a single plant species may have deleterious effects on associated animals and vice-versa, and loss of interactions may occur prior to species-extinction. Monitoring species-interactions is therefore directly related to environmental health and functioning, and studying complex interactions through accurate, cost-effective sampling can aid in the management of detrimental anthropogenic impacts. Conventional PAI monitoring methods (e.g., camera, malaise, and pitfall traps) are potentially invasive, time-consuming, and often unable to achieve species-specific detection. While DNA barcoding of gut contents or bulk samples provides species-specific detection, saves time, and enables simultaneous detection of many taxa, these methods remain potentially invasive and may require the sacrifice of study organisms. Alternatively, non-invasive environmental DNA (eDNA)-based monitoring provides accessible collection of biological signatures from the environment (air, water, soil) that can elucidate PAI. Environmental DNA methods have accurately detected plant-pollinator, plant-herbivore, and even some mutualistic relationships, from single-interacting species to the whole interacting community. In addition, a time-series of ecological interactions can be facilitated with eDNA methods. Although PAI studies using eDNA methods remain in their infancy, to date they have identified higher numbers of taxa in several direct comparisons to DNA-based gut/bulk sampling and conventional survey methods. Therefore, research into the influencing factors of eDNA detection involved in PAI (e.g., sources and types, methodological standardization, database limitations, validation with conventional surveys, and existing ecological models) will benefit the growth of this application. Involvement of environmental RNA (eRNA) can further strengthen eDNA-based methods, provide a better understanding of complex species-interactions, and help to avoid false positive results. Thus, implementation of eDNA methods to study PAI can particularly benefit environmental biomonitoring surveys that are imperative for biodiversity health assessments.