Hibiscus Sawfly: Identifying and Controlling the Lace-Like Leaf Damage

Hibiscus leaves chewed into "eyelet lace" between veins signal hibiscus sawfly larvae—greenish caterpillar-like larvae feeding on leaf undersides in early summer.

Key Distinction

Sawfly larvae have 6+ prolegs (caterpillars have ≤5). This matters because Bacillus thuringiensis (Bt) kills caterpillars but NOT sawflies.

Control Options

• Contact sprays: Insecticidal soap, permethrin, carbaryl applied in May-June
• Systemic: Imidacloprid soil drench before feeding starts
• Low-toxicity approach: Insecticidal soap every 7 days during larval activity

Both synthetic options have moderate fish toxicity—consider soap near water features.