Sustainable management strategies for Acarine Pests of Industrial Hemp (Cannabis sativa subsp. sativa L.)

Authors: CANON, MARIA - University Of Florida; SILVA ATAIDE, LIVIA - University Of Florida; VILLAMARIN, PAOLA - University Of Florida; DE GIOSA, MARCELLO - University Of Florida; OSBORNE, LANCE - University Of Florida; Tabanca, Nurhayat; LAHIRI, SRIYANKA - University Of Florida; REVYNTHI, ALEXANDRA - University Of Florida

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2025
Publication Date: 12/2/2025
Citation: Canon, M.A., Silva Ataide, L.M., Villamarin, P., De Giosa, M., Osborne, L.S., Tabanca, N., Lahiri, S., Revynthi, A.M. 2025. Sustainable management strategies for Acarine Pests of Industrial Hemp (Cannabis sativa subsp. sativa L.). Agronomy. 15,2785. https://doi.org/10.3390/agronomy15122785.
DOI: https://doi.org/10.3390/agronomy15122785

Interpretive Summary: Industrial hemp is an important alternative crop in Florida, generating an estimated $445 million in 2024. However, this crop faces a significant challenge such as high susceptibility to acarine (mite) pests, including spider mites (Tetranychidae), broad mites (Tarsonemidae), and russet mites (Eriophyidae). Management options are limited due to limited availability of federally registered and FDACS-approved products for mite control. Thus, scientists at the University of Florida and the USDA-ARS conducted research on biorational pesticides and predatory mites as part of an integrated pest management (IPM) strategy. Laboratory bioassays and greenhouse trials tested the effectiveness of various plant-derived oils and extracts against the primary mite species: Tetranychus urticae, T. gloveri, Polyphagotarsonemus latus, and Aculops cannabicola. Greenhouse trials confirmed that citric acid and garlic oil achieving 60–80% mortality within 24 hours against T. urticae. Efficacy of four species of predatory mites were evaluated for control of the russet mite (A. cannabicola). The most effective biological control agent was Amblyseius swirskii, which demonstrated the highest predation rate about 20 adults per 24 hours and strong reproduction. These findings strongly support incorporating citric acid, garlic oil, and thyme oil, along with predatory mite A. swirskii into Integrated Pest Management strategies for controlling acarine pests in Florida industrial hemp.

Technical Abstract: Industrial hemp (Cannabis sativa subsp. sativa L.) is an emerging crop in Florida, generating $445 million in 2024. However, it is highly susceptible to acarine pests, including spider mites (Tetranychidae), broad mites (Tarsonemidae), and russet mites (Eriophyidae). Management options are limited due to a few federally registered products approved by the Florida Department of Agriculture and Consumer Services (FDACS-DPI). Laboratory bioassays were conducted on hemp leaf discs infested with Tetranychus urticae, T. gloveri, Polyphagotarsonemus latus, or Aculops cannabicola, and treated with biorational pesticides (citric acid, rosemary, thyme, sesame, garlic, and mineral oil) at maximum label rates. Citric acid and garlic oil were most efficacious against T. urticae, while garlic and thyme oils were most efficacious against the other species, causing over 80% mortality. Greenhouse trials confirmed the efficacy of citric acid and garlic oil against T. urticae, achieving 60–80% mortality within 24 h. Predatory mites (Amblyseius swirskii, A. andersoni, Neoseiulus californicus, Galendromus occidentalis) were evaluated against A. cannabicola, with A. swirskii showing the highest predation (˜20 adults/24 h) and reproduction. Compatibility tests indicated thyme and garlic oils did not significantly affect A. swirskii survival (>70% alive after 24 h). These findings support integrated pest management strategies for hemp acarine pests.