Spider Mite Damage on Japanese Maple

Maryland Japanese maple: half bare, spiderwebs on branches/leaves, early browning, bark peeling. Fine last fall/winter.

Diagnosis: Spider Mites

• Pierce plant cells → tiny yellow/white speckles → bronzed foliage → premature drop.
• Heavy infestation: fine silk webbing, dusty appearance.
• Can kill if severe/recurrent.

Treatment

Miticide required—regular insecticides don't work. Spray both leaf surfaces thoroughly.

• Dicofol (Kelthane)—best but hard to find.
• Weak miticides (over-the-counter): Orthene, Cygon, Dursban, diazinon, Di-syston, malathion.
• Products labeled "mite suppression" are ineffective.

Confirm with white paper tap test. Bark peeling may be secondary to stress.