Holes in Peace Lily Leaves: Insects or Cultural Issue?

Diagnosing Mysterious Leaf Holes on Spathiphyllum

Peace lilies (Spathiphyllum spp.) are generally pest-resistant, but holes appearing in the middle of leaves—not from the edges—suggest mechanical damage or chewing insects. The presence of tiny black flies (likely fungus gnats) adds confusion, but gnat larvae feed on roots and fungi, not leaf tissue.

Possible Causes

• Chewing insects: Caterpillars, grasshoppers, or beetles may feed at night. Inspect leaf undersides, stems, and soil surface at dusk/dawn.
• Mechanical injury: Rough handling during transport or brushing against walls/pets can tear tender leaves, which then expand into holes as the leaf grows.
• Fungal/bacterial shot-hole: Rare on peace lilies; usually shows as small, round lesions with dark margins that fall out.

Action Plan

1. Scout thoroughly: Use a flashlight at night to catch nocturnal feeders. Check new growth first.
2. Remove affected leaves: Trim leaves with extensive holes to improve appearance and reduce disease entry points.
3. Treat if insects found: Apply insecticidal soap or neem oil weekly for 2–3 weeks. For persistent pests, a systemic granule (e.g., imidacloprid) can be used on ornamental houseplants.
4. Manage fungus gnats: Allow top inch of soil to dry between waterings. Use yellow sticky traps for adults. A soil drench with Bacillus thuringiensis israelensis (Bti) kills larvae.

When to Worry

If new leaves emerge hole-free and the plant is growing vigorously, the issue was likely transient. Continue monitoring; treat only if damage escalates.