A revision of the expansion of medical important scorpions in human areas in South America

 

South America has several medical important species of Tityus C. L. Koch, 1836 (Buthidae). Interestingly, scorpionism in South America is an urban problem that has been growing in the last decade as the medical species have had expansion of their distribution.

Alexis Emanuel Barrios-Montivero and coworkers have recently published a study presenting an updated overview of the current distribution of six medical important Tityus species. The study have looked at the original distribution of these species and their posterior expansion of synanthropic populations. In addition, the authors have tried to predict the future expansion of these medical important species.

The study shows that there have been a greatly accelerated expansion of medical important species in most cities of Southern South America in recent decades. In addition, they predict that there will be an even greater expansion of several of these species, and more important, they will reach countries and areas where scorpionism is not a problem today.

Abstract:
We revise the expansion of synanthropic medically important species of Scorpions of genus Tityus in southern South America: Tityus bahiensis (Perty 1833), Tityus carrilloi Ojanguren-Affilastro 2021, Tityus confluens Borelli 1899, Tityus costatus (Karsch, 1879), Tityus serrulatus Lutz & Mello, 1922, and Tityus trivittatus Kraepelin 1898, which due to their synanthropic capabilities we regard as invasive species. We also build species distribution models (SMDs) from bioclimatic variables using Maxent. We also included the human density variable in the model, because medically important species in the area are synanthropic, being more common in urban areas than in natural environments. We present their current suitable areas and the potential future distribution up to 2070. According to our analyses most species will expand in the close future, reaching countries without Scorpionism problems, such as Chile and Uruguay. We conclude that, besides synanthropic capabilities, parthenogenesis is the main factor favoring the expansion of some of these species. We also conclude that interactions between invasive Tityus species may hinder their expansion process due to potential competition or exclusion mechanisms.

Reference:
Barrios-Montivero AE, Martínez PA, Ojanguren-Affilastro AA. The Ongoing Expansion of the Medically Important Scorpions in Southern South America. Ecohealth. 2025. [Subscription required for full text]

Thanks to Andres Ojanguren for sending me this article!