Spider mites are tiny arachnids — not insects — that feed from the undersides of leaves by piercing individual cells and sucking out the contents. Each puncture destroys one cell's worth of chlorophyll, so the damage shows up on the leaf tops as tiny pale speckles called stippling. They thrive in hot, dry conditions and reproduce explosively — a handful of mites can become thousands in under two weeks. Two-spotted spider mites (Tetranychus urticae) are by far the most common species on cannabis. They're usually introduced on clones, clothing, or pets, and they're so small you won't notice them until the stippling gives them away. Don't confuse stippling with thrips damage — mites leave tiny dots in a scattered pattern, while thrips leave silver streaks along the veins. By the time you see webbing between branches, you're dealing with a serious colony that needs immediate action.
