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Catalpa Worms: Harmless Caterpillars That Only Feed on Catalpa Trees

Identification

The 2‑inch caterpillar with a rear horn is a catalpa worm (catalpa sphinx larva). It feeds exclusively on catalpa leaves and will not harm other garden plants or trees.

Control

If catalpa trees are present, the worms are natural. Hand‑pick caterpillars or spray foliage with Bacillus thuringiensis (BT), a bacterial insecticide specific to caterpillars. No treatment is needed for non‑catalpa plants.

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