Green Nature

New World Tarantulas

picture of a redknee tarantula


New World tarantulas rank among the most popular and least understood spiders in the United States.

The term new world tarantulas refers to the group of tarantulas (Theraphosidae) indigenous to North, South and Central America.

Generally they prefer warm habitats, with different species adapted to either life on the ground or life in the trees. The article New World Arboreal Tarantulas points out that the tree tarantulas are generally smaller in size than their terrestial counterparts.

On the terrestial side, the goliath birdeater (Theraphosa leblondi) of South America, commonly receives credit for being the world's largest spider, having a leg span that approaches one foot in length.

Of course not all new world tarantula species grow that large. Most of the fifty or so species in the United States, for example, measure less than six inches long with their legs extended.

The lack of agressiveness in the large, colorful and hairy terrestial species captured the imagination of a segement of the population, resulting in increased demand for these species as pets.

Species in the Brachypelma genus, new world tarantulas found from Mexico, south through Central America, fit those criteria. The top picture shows the Mexican redknee tarantula (Brachypelma smithi), one of the initial high demand species.

Eventually the increased demand threatened their existence in the wild, and in 1994 member states of CITES voted to restrict the Brachypelma trade.

Concerns about wild tarantula populations also led to increased study of the spiders in their native habitat.

A recent survey covering the Distribution and Natural History of Mexican Species of Brachypelma and Brachypelmides, for example, documents tarantula habitat. However, it does not address current population trends.

Tarantula populations in the United States are limited to areas west of the Mississippi River and south of Missouri. States in the tarantula's range are engaged, to varying degrees, in collecting more reliable habitat and population statistics.

© 2008. Patricia A. Michaels