Video: How to Identify Symptoms of Hemp Russet Mite

Hemp Russet Mite is a tenacious, microscopic arthropod that can damage your crop. The video below can help you learn how to spot symptoms of this pest before it is too late.

Hemp Russet Mite (Aculops cannabicola) is a type of microscopic arthropod that feeds on leaves, new growth, flower buds, and on glandular trichomes of cannabis (Petanovic, 2007). Hemp Russet Mite belongs to the Eriophyidae family of mites which are economically significant crop pests in citrus, apples, grapes, hazelnuts, coconuts, and tomatoes. Symptoms of Hemp Russet Mite damage can be confused with nutrient deficiencies, viruses, and physiological disorders (Van Leeuen, 2010).  Hemp Russet Mite has the potential to be a major pest issue for medical and adult-use cannabis production. Hemp Russet Mite infestations have been reported in both indoor and outdoor legalized cannabis production in California, Oregon, Colorado, and Washington.

Hemp Russet Mites are closely related and belong to the same genus as the Tomato Russet Mite. Studies of the Tomato Russet Mite show that Russet mite populations are suppressed under very cold temperatures or under high temperatures above 86 degrees F (Gerson, 2012). In areas with very cold winters, pest populations decline dramatically.  Cannabis plants infected with Hemp Russet Mite and are held year-round in climate controlled greenhouses or indoor grow facilities where temperatures don’t drop below freezing are a potential vector for spreading Hemp Russet Mite—especially if mite infested plants are used to propagate clones.  As legalized cannabis production expands, many cannabis producers are acquiring cloned plants from other farms and inadvertently introduce Hemp Russet Mite onto their farms.