What does a spider mite look like on an apple tree? - briefly
Spider mites on apple trees are microscopic (≈0.2–0.5 mm), oval, yellow‑green to reddish, and produce fine silk webs on the leaf undersides. Infested foliage displays stippled, speckled discoloration and a dusty appearance.
What does a spider mite look like on an apple tree? - in detail
Spider mites on apple trees are microscopic arachnids, typically 0.2–0.5 mm in length. Adults are oval‑shaped, their bodies flattened laterally, giving a teardrop silhouette when viewed from above. The dorsal surface bears a soft, translucent coating that may appear pale green, yellow, or reddish, depending on species and feeding stage. Legs are short, six in total, and barely visible without magnification.
Key visual indicators include:
- Fine, silvery webbing on the underside of leaves, especially along veins and around shoot tips.
- Stippled or speckled discoloration on foliage, caused by mite feeding that extracts cell contents and leaves tiny, pale spots.
- Leaf stippling that coalesces into bronzed or bronzy‑orange patches as damage progresses.
- Presence of tiny moving specks when the leaf is shaken; these are adult mites or motile nymphs.
Life‑stage differences are noticeable under a hand lens:
- Eggs: oval, smooth, laid singly or in clusters on the leaf underside; color ranges from white to light yellow.
- Larvae (protonymphs): six legs, slightly smaller than adults, translucent with a faint greenish hue.
- Nymphs (deutonymphs): eight legs, similar coloration to adults but without developed setae.
- Adults: as described above, may develop faint setae (hair‑like structures) along the body margins, giving a slightly fuzzy appearance.
Infested trees often exhibit a pattern of damage concentrated near new growth, where spider mites preferentially feed. The combination of microscopic size, distinctive webbing, and characteristic leaf stippling provides a reliable basis for field identification without laboratory analysis.