Controlling Oleander Caterpillars on Desert Rose

A Central Florida gardener finds small, thin, orange caterpillars with black spines devouring desert rose plants. The caterpillars are likely the larvae of the oleander caterpillar moth (Syntomeida epilais), which sequesters toxins from the plant, making them poisonous to birds.

Organic Control Options

• Spinosad: Fast-acting; caterpillars die after a few bites. Green Light Lawn & Garden Spray with Spinosad is a good brand.
• Bacillus thuringiensis (Bt): Slower but effective; must be ingested. Reapply after rain or new hatch.
• Hand-picking: Wear heavy gloves; caterpillar spines and plant sap can irritate skin.

Follow-Up

One application is rarely enough. Organic products don't persist. Re-spray when new caterpillars appear. Desert roses are resilient; occasional defoliation won't kill established plants.