Wolf spiders (Lycosidae) vs. Wandering spiders (Ctenidae): Key Differences.

Introduction

Spiders often spark confusion due to their diversity and superficial similarities. Two groups frequently mistaken for each other are wolf spiders (family Lycosidae) and wandering spiders (family Ctenidae, such as the notorious Phoneutria). Though both are agile hunters, they belong to distinct families with unique traits. Spiders of the genus Cupinneus now belong to a family called Trechaleidae (trechalid spiders) previously found in the family Ctenidae (ver familia aqui :Observaciones · Naturalista Costa Rica)

1. Taxonomy and Distribution

Feature	Wolf Spiders (Lycosidae)	Wandering Spiders (Ctenidae)
Family	Lycosidae	Ctenidae
Costa Rican Species	Schizocosa avida, Sosippus agalenoides	Phoneutria boliviensis, Ctenus ornatus
Geographic Range	Global (except polar regions)	Neotropical (Costa Rica’s rainforests, Central/South America)

2. Morphology: How to Tell Them Apart

Wolf Spiders

Foto 479497668, (c) maticus, algunos derechos reservados (CC BY-NC), subido por maticus · iNaturalist

• Body: Stocky, with short, powerful legs for sprinting.

• Eyes: Eight eyes arranged in three rows (bottom row: four small eyes; middle: two large; top: two medium).

• Coloration: Earth tones (brown, gray, black) with camouflaged patterns.

• Special Features: Females carry egg sacs attached to their spinnerets. List of Costa Rican Species: Observaciones · Naturalista Costa Rica

Wandering Spiders (Ctenidae)

Foto 486234865, (c) raulbermudez, algunos derechos reservados (CC BY-NC) · iNaturalist

• Body: Slender, with long, spiny legs for climbing.

• Eyes: Eight eyes in two horizontal rows (lower row often wider).

• Coloration: Reddish-brown, with contrasting stripes or spots (e.g., Phoneutria has a dark abdomen with red chelicerae).

• Special Features: Spines on legs and enlarged forward-facing chelicerae (fangs). List of Costa Rican Species: Observaciones · Naturalista Costa Rica
  

  3. Venom: Risks to Humans

  
  

  Wolf Spiders:

  
  

  • Venom targets insects; harmless to humans.

  
  

  • Bites may cause mild pain or swelling.

  
  

  Wandering Spiders (e.g., Phoneutria):

  
  

  • Highly neurotoxic venom (contains PhTx3, affecting nerve signals).

  
  

  • Medically significant: Bites can cause severe pain, sweating, tachycardia, and (rarely) respiratory failure. Immediate medical care is critical.
    

    Want to Learn More?

    References:

    
    

    Instituto Nacional de Biodiversidad (Costa Rica): https://www.inbio.ac.cr/

    
    

    World Spider Catalog: https://wsc.nmbe.ch/