Spider mites can cause stippled, pale tomato leaves before fine webbing becomes obvious. Inspecting early helps you distinguish mite damage from nutrient stress and choose a treatment that protects beneficial insects.
Inspect the undersides
Look beneath leaves with a flashlight for tiny moving specks, pale stippling, shed skins, and delicate webbing. Tap a leaf over white paper and watch for movement. Hot, dry conditions often favor outbreaks.
Reduce stress
Water the root zone consistently and improve airflow without stripping the plant bare. Remove heavily damaged leaves with clean pruners and keep them out of the compost if the cause is uncertain.
Use a targeted treatment
For a light infestation, a firm water spray directed at leaf undersides may help. If a labeled soap or oil is needed, follow the product instructions, avoid heat, and observe the harvest interval.
Inspect twice a week during hot weather. Early action is gentler than waiting for the canopy to collapse.