🕷️ Two-Spotted Spider Mite

🔍 Identification

Adults: 0.4mm — barely visible to naked eye; greenish-yellow with two dark dorsal spots (the spots are gut contents visible through translucent body); found on leaf undersides in fine webbing. Damage: stippled, bronzed, or yellowing leaves; fine webbing on leaf undersides and between leaves (distinctive); leaf drop in severe cases. Paper test: tap leaves over white paper — moving dots confirm mites.

🧬 Biology & Behavior

At 70°F: egg to adult in 14 days. At 90°F: egg to adult in 5 days. Population doubling time: 3-5 days in optimal conditions. This explosive growth rate means a mild infestation in June becomes plant-killing in July during heat waves. Pesticide resistance is widespread in T. urticae — many populations have resistance to abamectin, bifenazate, and organophosphates. Rotate modes of action always.

⚠️ Damage & Health Risk

Leaf stippling and bronzing; reduced photosynthesis; premature defoliation; plant death in severe infestations on susceptible crops; economic losses in vegetable, ornamental, and greenhouse production.

🔧 DIY Treatment

Forceful water spray dislodges mites and eggs — effective on small plants. Insecticidal soap (2-3%) on leaf undersides. Neem oil spray. Miticide rotation: bifenazate (Floramite) → spiromesifen (Forbid) → abamectin (Avid) — never repeat the same product. Biological control: predatory mites (Phytoseiulus persimilis, Neoseiulus californicus) in greenhouses.

👷 When to Call a Pro

Commercial: strict resistance management with miticide rotation; predatory mite release programs in greenhouse production.

❓ FAQ