In a nutshell: a very small mite, difficult to detect; hemp/cannabis host; causes stunting of the plant
What are Hemp Russet Mites?
Hemp Russet Mites (Aculops cannabicola) belong to the family Eriophyidae (gall and rust mites). All life stages of the hemp russet mite are extremely small and difficult to observe. Damage is caused by the mites sucking out the contents of plant cells.
What kinds of plants do they attack?
Cannabis/Hemp Plants (Cannabis sativa). It cannot survive on other plants.
What do they look like?
They are elongated (torpedo-shaped), soft and segmented. The body appears to be divided into two parts: the head with the mouthparts, and the rest of the body. All mobile stages have only two pairs of legs, whereas other mite groups have four pairs.
The hemp russet mite has four life stages: egg, two nymphal stages and adult. The nymphal stages are sometimes also called larva (1st stage) and nymph (2nd stage). The eggs are approximately 0.05 mm in diameter and adults are around 0.2 mm long. Nymphs and adults look very similar.
How do I know if my plants are under attack?
Hemp russet mite develops on the stems and petioles of the hemp plant and can cause stunting. When populations are large, the mites can also be found on the underside of leaves. This results in smaller leaf size and suppressed bud growth leading to a reduction in the number of buds and dwarfed buds. This damage can reduce yield and quality. Other signs of damage include dull, greyish, or bronzed leaves and upward curling of leaf edges.
How to get rid of Hemp russet mite
Koppert offers different solutions for biological pest control of Hemp russet mite.