What does a spider mite look like on leaves? - briefly
Spider mites are microscopic (0.2–0.5 mm) pale yellow‑green or reddish specks that congregate on the leaf underside, often surrounded by fine silken webbing. Their feeding produces stippled, bronze‑colored discoloration and may cause leaves to curl or dry out.
What does a spider mite look like on leaves? - in detail
Spider mites are microscopic arachnids, typically 0.2–0.5 mm in length, so they are invisible to the naked eye without magnification. On the leaf surface they appear as tiny specks that may be yellow, green, brown, or reddish, depending on species and age. Their bodies are oval, flattened, and covered with fine hairs that give a slightly fuzzy texture when examined under a hand lens.
The most recognizable damage includes:
- Stippled or stippled‑looking discoloration: tiny, translucent spots where the mite has pierced the cell wall, creating a mosaic of light‑colored patches that may coalesce into larger yellow or bronze areas.
- Webbing: fine, silk‑like strands radiating from the leaf edge or the undersurface, often visible as a delicate curtain covering the affected area. Webbing is most abundant when populations are high.
- Leaf curling and distortion: excessive feeding causes the leaf margins to curl upward or downward, sometimes producing a blistered appearance.
- Premature leaf drop: severe infestations weaken the leaf, leading to early abscission.
Life‑stage differences are also evident. Eggs are oval, pale, and usually laid on the lower leaf surface in clusters of 20–50. Nymphs (or "deutonymphs") resemble adults but lack fully developed setae and appear lighter in color. Adult females are larger and often more pigmented than males, which are slender and less conspicuous.
When assessing foliage, a 10× magnifying glass or a stereo microscope reveals the mite’s leg count (four pairs) and their characteristic elongated, spindle‑shaped bodies. The presence of webbing combined with stippled chlorosis provides a reliable field diagnosis without laboratory analysis.