Chinch Bug vs. Fungus in St. Augustine: How to Tell

The Soap Flush Test (2-2-2 Method)

1. Mix 2 oz dish soap in 2 gallons water.
2. Pour slowly over 2 sq ft of transition zone (brown meeting green).
3. Wait 3–5 minutes—insects surface.

Identify Chinch Bugs

• Adults: Black, 1/5", white wings folded.
• Nymphs: Bright red/orange with white band.
• Threshold: >20 per sq ft = treat.

If No Bugs Found

Consider:

• Fungus (brown patch, take-all root rot) – circular patches, yellow halos.
• Dog urine, oil spill, fertilizer burn.
• Drought stress – probe soil moisture.

Correct ID saves money and prevents unnecessary fungicide/insecticide use.