How to spot a spider mite? - briefly
Spider mites are tiny, often red or yellow, moving specks on leaf surfaces, accompanied by fine silk webs and stippled, yellow‑brown discoloration of foliage. Inspect the undersides of leaves with a magnifying lens to confirm the presence of the eight‑legged pests.
How to spot a spider mite? - in detail
Spider mites are tiny arachnids that often go unnoticed until plant damage becomes evident. Early detection relies on close observation of foliage and the insects themselves.
Leaves may display a stippled or speckled appearance caused by the mites feeding on cell contents. The discoloration usually starts as pale yellow spots that may merge into larger bronzed patches. Fine webbing, sometimes visible on the undersides of leaves or along stems, indicates an established colony. The web is delicate, resembling a silk sheet only a few millimeters thick.
Individual mites measure 0.2–0.5 mm and possess a translucent, oval body with two pairs of front legs and four pairs of walking legs. Under a magnifying lens or low‑power microscope, the dorsal surface shows a pattern of elongated, red‑brown setae. The absence of a visible mouthpart is typical; feeding occurs through a stylet that pierces plant cells.
Damage patterns help confirm presence. When mites extract sap, leaf tissue collapses, producing a “blotchy” effect that can progress to leaf curling, premature drop, or stunted growth. In severe infestations, entire plants may appear wilted despite adequate watering.
Effective monitoring techniques include:
- Inspecting leaf undersides with a hand lens of at least 10× magnification three times per week during warm periods.
- Placing yellow sticky cards near susceptible plants; mites are attracted to the color and become trapped.
- Conducting a leaf‑wash test: submerge a leaf in water, agitate gently, then examine the runoff for moving specks under a microscope.
- Recording the number of web strands per leaf; a threshold of five or more suggests a population surge.
Prompt identification allows targeted control measures before the population reaches damaging levels.