Brown Recluse

📐 FIELD GUIDE ILLUSTRATION

Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.

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PestControlBasics Editorial Team

Reviewed by Derek Giordano · Updated 2026

🔍 Identification

Definitive ID requires: 6 eyes (3 pairs in a semicircle) — most spiders have 8 eyes. Violin-shaped marking on cephalothorax (unreliable alone — many spiders have similar markings). Uniform abdomen color — no mottling, spots, or banding. 8-15mm body. Get a photo — the 6-eye pattern requires magnification to confirm.

🧬 Biology & Behavior

Verified range: Missouri, Arkansas, Oklahoma, Kansas, Tennessee, Kentucky, Alabama, Mississippi, Louisiana, Texas, Nebraska, Iowa, and adjacent states. NOT established in: California (occasional importations only), New England, Pacific Northwest, or most of Florida. This geographic reality is critical — the vast majority of 'brown recluse bites' diagnosed in California or New York are something else.

⚠️ Damage & Health Risk

Necrotic wound (rare — occurs in 10-15% of documented bites); systemic effects (rare); significant tissue damage in severe cases. The majority of brown recluse bites cause minimal or no symptoms.

🔧 DIY Treatment

Inside verified range: sticky traps placed along walls (they walk the floor); reduce clutter where they hide; professional residual spray in voids. Don't shake out clothing in affected areas. Keep shoes off the floor in infested buildings.

👷 When to Call a Pro

In verified range with heavy infestations: professional void treatment with residual spray and desiccant dust.

❓ FAQ

I'm in California — is this a brown recluse?

Almost certainly not. Brown recluse is not established in California despite many reports. The desert recluse (Loxosceles deserta) exists in the desert Southwest but is rarely encountered. Common California spiders misidentified as brown recluse include hobo spiders (not dangerous), yellow sac spiders (mild bite), and wolf spiders (large, fast, scary-looking but harmless). Post the photo to r/spiders — identification is usually quick.

What should I do if I'm bitten by a brown recluse?

If inside the verified range: clean the wound, apply ice, mark the edge of any redness with a pen and mark the time to track progression, and see a doctor. Save the spider if possible for definitive ID. The vast majority of bites require only wound care — severe necrosis is relatively rare and systemic effects are very rare.

🕷️ Brown Recluse Spider