Worldwide distribution of tarantula hawks includes areas from India to Southeast Asia, Africa, Australia, and the Americas. Tarantula hawk species have been observed from as far north as Logan, Utah, in the United States, and south as far as Argentina in South America, with at least 250 species living in South America.[5] Eighteen species of Pepsis and three species of Hemipepsis are found in the United States,[6] primarily in the deserts of the southwestern United States, with Pepsis grossa (formerly Pepsis formosa)[7] and Pepsis thisbe being common. The two species are difficult to distinguish, but the majority of P. grossa has metallic blue bodies and reddish antennae, which separates them from P. thisbe.