Controlling Nocturnal Caterpillars on Bougainvillea with Bacillus Thuringiensis (BT)

Night‑Feeding Caterpillars on Bougainvillea

The "eaters" are caterpillars that hide by day and feed at night, leaving black frass (specks) on the sidewalk.

Biological Control

• Spray Bacillus thuringiensis (BT) on the undersides of leaves in late afternoon.
• BT is non‑toxic to humans, pets, and beneficials; it stops caterpillar feeding within hours.
• Reapply after rain or weekly until damage stops.

No need for harsh chemicals—BT is specific and effective.