Vagrant-mite
Guides
Aculops cannabicola
hemp russet mite, HRM
Aculops cannabicola, the hemp russet mite, is a highly specialized eriophyoid mite and among the most serious pests of Cannabis sativa. First described from Hungary in 1960, it has since been detected across multiple continents including North America, Central Asia, and Europe, with its first Italian record in 2021. The mite causes distinctive rust-colored damage to leaves, curling of leaf edges, and russeting, and can reduce flower and seed production by 50-90%. It feeds on all plant parts including leaves, petioles, inflorescences of both sexes, and glandular trichomes, drastically reducing resin production. Control is notoriously difficult; the mite persists year-round in dry, warm habitats and complete eradication typically requires destroying all plants and sterilizing surfaces.