Insect Identification
Insect Identification

Mexican Orange-Kneed Tarantula - (Euathlus smithii)

Authored By Staff Writer | Last Updated: 1/24/2014

The endangered Mexican Orange-Kneed Tarantula is protected by international laws so it can remain a part of its natural ecosystem for generations to come.

Picture of Mexican Orange-Kneed Tarantula

Tarantulas are magnificently large and extremely hairy. Including legs, some can grow as long as 150 mm. This particular species has bright orange patches on its "knee" joints and lower legs joints as well and it is this unique coloration has led to their decline.

Orange-Kneed Tarantulas became popular 'pets' and were taken from the wild and sold in stores. Their trade has now become illegal and they are protected as an endangered species by being placed on the CITES list.

Males are generally smaller and thinner than females, though their legs are longer. They are territorial and aggressive with other intruding males. Females are larger and live longer by an average of 10-20 years longer. Males generally live about 10 years, when they become sexually mature, and then die.

North American tarantula venom is not lethal, but bites can be as painful as a bee sting. Also, the bristles on their abdomen break off easily and can penetrate skin, causing irritation and redness to prey (mice) or people trying to handle them. This is a 'look, but don't touch' species.

Nocturnal in nature, they are most active at night and are hunters, not spinners. They may use their silk to line their daytime hideouts, but not to catch prey.

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Category: Spider
Common name: Mexican Orange-Kneed Tarantula
Scientific Name: Euathlus smithii

  Kingdom: Animalia
   Phylum: Arthropoda
    Class: Arachnida
     Order: Araneae
      Family: Theraphosida
       Genus: Euathlus
        Species: smithii

Adult Size (Length): 35mm to 60mm (1.38in to 2.36in)

Identifying Colors: black, orange, gray, white

Additional Descriptors: hairy, orange, knees, biting, venomous

North American Reach (Though Not Limited To*): Arizona; Nevada; New Mexico; Texas; Mexico

* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.