Crabapple Leaf Spikes: Likely Cedar-Apple Rust, Not Insects

What You’re Seeing

“Tall curved spikes” erupting from brown spots = cedar-apple rust galls (fungal), not insects. Fruit unaffected is typical.

Snip affected twig, bag it, take to local nursery for confirmation.
If rust: fungicide sprays (myclobutanil, propiconazole) at pink-bud stage next spring.
Remove nearby junipers (alternate host) if feasible.

ID first. Indiscriminate spraying kills beneficials. Use IPM—target the confirmed problem.

Pests: Artillery Fungus from Potted Palm: Soil Surface Issue; Grapefruit Tree Webs: Beneficial Psocids, Not Pests; Ants on Crabapple Trees: Friend or Foe?; Gray Marshmallow Masses on Tree: Harmless Lichens; Identifying and Treating Borer Infestation in Crabapple Trees; Managing Borers in Crabapple Trees and Aphids on White Pines; Defoliating Caterpillars on Willow Oak: Identification and Control; Birch Tree Caterpillar Infestation: Identification and Safe Control; Twig Galls on Young Trees: Harmless Wasp Homes; Scale on Ficus: Identification and Alcohol‑Soap Treatment

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