Red & Black Worms on Lilies After Rain: Likely Lily Leaf Beetle Larvae

Central NY: Skinny, long red-and-black worms covering lily petals/leaves after heavy rain. Eating holes in plants for years. Never seen these before.

Probable ID: Lily Leaf Beetle Larvae (Lilioceris lilii)

• Larvae: Orange-red with black heads, cover themselves in black fecal shield (look "red and black").
• Adults: Bright red, 1/4 inch, squeak when squeezed.
• Feed exclusively on true lilies (Lilium) and fritillarias.

Organic Control (Same for Most Caterpillars/Worms)

1. Bacillus thuringiensis (Bt): Powder (Dipel, MVP, Green Step). Apply to foliage. Caterpillars eat, stop feeding, die in days. Organic, safe.

2. Diatomaceous Earth: Fossilized diatom powder. Abrasive to soft bodies—causes dehydration. Dust on plants and soil.

3. Hand-pick: Daily inspection, drop in soapy water.

4. Neem oil: Repels adults, disrupts larval growth.

Start early next spring. Lily leaf beetles can destroy plants quickly.