PestKeen

Spider Venom Threat Scale

Most spiders are harmless friends that eat flies. Only a few in North America are medically significant. Know the difference.

Medical Disclaimer

This guide is for identification only. If you are bitten by a Black Widow or Brown Recluse, or experience difficulty breathing, dizziness, or severe swelling, seek emergency medical attention immediately.

Friend or Foe?

In North America, there are only two main groups of spiders that are medically significant:

  • Widows (Latrodectus): Including the Black Widow. Neurotoxic venom.
  • Recluses (Loxosceles): Including the Brown Recluse. Necrotic venom (tissue destroying).

Almost every other spider you encounter (Wolf Spider, Orb Weaver, Jumping Spider, Cellar Spider) is harmless to humans and actually helps you by eating flies and mosquitoes.