What does a spider mite look like on grape leaves? - briefly
Spider mites are tiny (≈0.2 mm), translucent to yellowish specks that cluster on the underside of grape leaves, causing stippled or bronzed discoloration. Fine silk webbing may be seen between leaf veins, particularly in dry conditions.
What does a spider mite look like on grape leaves? - in detail
Spider mites on grape vines are microscopic arachnids, typically 0.2–0.5 mm long, so they are invisible to the naked eye unless present in large numbers. Individual bodies are oval, flattened, and range from pale yellow to light green, sometimes appearing reddish when heavily infested. Their legs are long, slender, and often visible as tiny hairs extending from the edges of the leaf surface.
Visible signs include:
- Fine, silvery webbing on the underside of leaves, especially along veins and leaf margins.
- Stippled or stippled discoloration: tiny yellow‑white spots where mites have fed, giving the leaf a mottled appearance.
- Leaf bronzing or chlorosis that progresses to a stippled, ash‑gray texture as feeding damage spreads.
- Early leaf drop in severe cases, with leaves turning brown and curling at the edges.
The feeding activity creates a “scraped” look, as mites pierce plant cells and extract sap. This results in a translucent, almost glassy appearance of the leaf tissue, often accompanied by a faint, powdery residue from mite excrement. On heavily infested vines, the combination of webbing, discoloration, and leaf distortion provides a reliable field diagnosis of spider mite presence.