What does damage caused by a spider mite look like? - briefly
Infested leaves display minute yellow or stippled spots that turn bronzed or mottled, accompanied by fine webbing on the undersides. Heavy feeding leads to leaf curling, premature drop, and overall plant weakening.
What does damage caused by a spider mite look like? - in detail
Spider mite feeding creates a distinctive pattern of damage on foliage. The insects pierce leaf cells with their mouthparts, extracting plant fluids. This results in a mottled, stippled appearance where tiny, pale or yellowish spots replace the normal green tissue. As the infestation intensifies, the spots coalesce into larger, irregularly shaped blotches that may turn bronze, brown, or necrotic.
Typical visual indicators include:
- Fine stippling: minute, translucent specks visible on the upper and lower leaf surfaces.
- Leaf bronzing: a uniform, metallic sheen that spreads outward from the stippled area.
- Webbing: fine, silk-like threads, especially on the undersides of leaves, branches, and near leaf axils.
- Curling or distortion: leaves may curl upward or downward, become twisted, or develop puckered edges.
- Premature leaf drop: heavily damaged foliage often abscises earlier than healthy leaves.
- Stunted growth: new shoots exhibit reduced vigor, with smaller, deformed leaves.
The damage pattern varies with plant species. On broadleaf ornamentals, stippling is readily seen on both leaf surfaces, while on conifers the symptoms appear as yellowing of needle tips and webbing among the foliage. In fruiting crops, such as tomatoes or strawberries, the feeding sites can cause blossom drop and reduced fruit set.
Progression follows a predictable sequence. Initial feeding creates isolated stipples; as the mite population expands, stipples merge, forming larger chlorotic zones. Web production escalates, providing shelter and facilitating further reproduction. Without intervention, the cumulative loss of photosynthetic tissue leads to weakened plants, increased susceptibility to secondary pathogens, and ultimately significant yield reduction.
Accurate diagnosis relies on close inspection of leaf surfaces with a magnifying lens (10–30×). Adult spider mites are less than 0.5 mm, typically red, yellow, or green, and can be seen moving among the webbing. Eggs appear as tiny, oval, light-colored bodies attached to leaf undersides. Detecting these life stages confirms the cause of the observed foliar damage.