D3135: Development and validation of a novel real-time PCR assay for rapid detection of hemp russet mite

Cannabis sativa, or hemp, is becoming an increasingly important agricultural crop worldwide. Pest species affecting hemp in the United States have been documented, however, there is little understanding of their biology and control. One species of particular importance, the Hemp Russet Mite (Aculops cannabicola, HRM) is a microscopic arthropod which feeds on developing hemp plants. Due to its minute size, HRM can go unrecognized until population numbers are so large that they have already damaged crops, and their economic impact is likely underestimated. Cannabis is known for its unique metabolic properties including cannabinoids such as CBD, but research addressing the role of cannabinoids in plant resistance to HRM is missing. This study intends to report the developmental effects of both low and high-CBD hemp varieties on HRM and to develop molecular markers from a related species to identify HRM infestations early. Our results show that mites reared on high-CBD hemp had decreased fecundity and longevity compared to those reared on low-CBD hemp. Additionally, molecular markers for HRM have been developed and are being used in qPCR analysis against non-target species sampling. Outcomes of this research will provide hemp producers and stakeholders with a better understanding of this pest and a tool for early detection