10 August, 2021

A new medical significant Tityus species from Argentina


The genus Tityus C. L. Koch, 1836 (Buthidae) contains some of the most medical significant species in South America and in the world. One the the most infamous species is Tityus trivittatus Kraepelin 1898, a species known to cause death and serious morbidity in parts of Brazil, Paraguay, Uruguay and Argentina.

Andrés Alejandro Ojanguren Affilastro and co-workers have recently done a taxonomic and phylogenic study of Tityus trivittatus. Their study shows that the poplations of T. trivittatus in Argentia is acutally a separate species.

Tityus carrilloi Ojanguren Affilastro, 2021 (Argentina)

We know that the new species is medically significant because this has been documented for these populations previously (as Tityus trivittatus). The discovery of this new species is important, as the venom content of T. trivittatus and T. carrilloi vary and this may have consequences for the treatment of sting patients. 

This is an important study as knowledge about the taxonomy of venomous species is important both for treatment and prevention and control.

Tityus trivittatus is considered the most medically important scorpion species of southern South America. In this contribution we redefine its taxonomy, redescribe the species and separate the southern populations as a new species, Tityus carrilloi n. sp. As a consequence of this description, the most medically important species of the region turns out to be the new species herein described. We also clearly establish the phylogenetic position of both species through a dated molecular phylogenetic analysis based on four genes. Finally, we discuss the differences of the venom between the two species, and the epidemiologic implications of our results on the scorpionism problem in the region.

Ojanguren A, Kochalka J, Orellana D, Garcete Barrett BR, Borges A, Ceccarelli F. Redefinition of the identity and phylogenetic position of Tityus trivittatus Kraepelin 1898, and description of Tityus carrilloi n. sp. (Scorpiones; Buthidae), the most medically important scorpion of southern South America. Revista del Museo Argentino de Ciencias Naturales, Nueva Serie. 2021;23:27-55. [Open Access]

Family Buthidae

06 August, 2021

Relationship between scorpion sting events and environmental conditions in mainland France


Jules-Antoine Vaucel and co-workers have published a thorough study of scorpion stings in mainland France. This is interesting in itself and I find it especially interesting that they report of one event of scorpion sting involving the enigmatic B. xambeui Simon, 1879 (Belisaiidae). Unfortunately, they present no details on this incident, but I guess it caused no serious morbidity. Other species represented in the study were Buthus occitanus (Amoreux, 1789) (Buthidae) and Euscorpius concinnus (Koch, 1837), Euscorpius italicus (Herbst, 1800), Euscorpius tergestinus (Koch, 1837), and Tetratrichobothrius flavicaudis (De Geer, 1778) (all in the family Euscorpiidae).

As the title indicate, the authors have tried to find a relationship relationship between scorpion sting events and environmental conditions like level of sunshine, temperature etc. The authors conclude that climatic variations could well predict encounters between humans and scorpions in France. 

In the world, the impact of environmental conditions on the number of scorpion events was evaluated in North Africa,Middle East, and the Amazonian region but not in Europe. In mainland France, scorpion species described are Buthus occitanus (Amoreux, 1789), Belisarius xambeui (Simon, 1879) and 4 Euscorpiidae: Euscorpius concinnus (Koch, 1837), Euscorpius italicus (Herbst, 1800), Euscorpius tergestinus (Koch, 1837), and Tetratrichobothrius flavicaudis (De Geer, 1778). We aimed to describe the impact of environmental conduction on the number of scorpion events. For this, a retrospective multi-center study was conducted with data from the French poison control centers files about scorpion events between 1 January 2011 and 31 December 2020. During the study period, 975 incoming calls for scorpion events were recorded and 574 were related to scorpions native to mainland France and Corsica: B. occitanus (n = 86), Euscorpiidae species (n = 222), B. xambeui (n = 1), and undetermined species (n = 265). Cases were mostly reported along the Mediterranean coast, along rivers, and in cities with a trading port. The number of scorpion events was linked to the rivers' water level, rivers' flow, temperature, sunshine, and pluviometry (P < 0.05 for all variables). B. occitanus need warmest and driest environment than Euscorpiidae spp. A link between the severity of the envenoming and climatic condition or seasonality was not demonstrated.

Vaucel JA, Larreche S, Paradis C, Labadie M, Courtois A, Grenet G, et al. Relationship Between Scorpion Stings Events and Environmental Conditions in Mainland France. J Med Entomol. 2021. [Subscription required for full text]

04 August, 2021

Yet another species of Buthus from Algeria


Haroun Abidi and co-workers have described a new species of Buthus Leach, 1815 (Buthidae) from the coastal region of El-Tarf, in the north-eastern range of Algeria.

Buthus goyffoni Abidi, Sadine & Lourenco, 2021

A revised diagnosis of Buthus paris (C. L. Koch, 1839) is also given.

One more new species of Buthus is described from the coastal region of El-Tarf, in the north-eastern range of Algeria. This new species may represent a possible vicariant element of Buthus paris (C. L. Koch, 1839), a species equally known from the north of Algeria, but inhabiting much higher altitudes in the coastal massifs. The number of confirmed species of Buthus in Algeria is raised to nine.

Abidi H, Sadine SE, Houhamdi M, Madoui A, Lourenco WR. The genus Buthus Leach, 1815 in Algeria (Scorpiones: Buthidae) and a possible new case of vicariant species. Revista Iberica de Arachnologia. 2021(38):81-6.

Thanks to Dr. Sadine for sending me their article!

Family Buthidae

03 August, 2021

A phylographic study of the widespread, southern devil scorpions Vaejovis carolinianus in the USA


Several studies have revealed cryptic spices within the genus Vaejovis C.L. Koch, 1836 (Vaejovidae) in the southeastern USA. With this in mind, Matthew Graham and co-workers have conducted a thorough phylographic analysis of the more widespread species Vaejovis carolinianus (Beauvois, 1805). 

The authors expected to find cryptic species in some of the different populations of this species, but the genetic analysis did not support this. Even though several genetical clades were identified, all populations are the same species. 

Check out the article to learn more about the phylography of Vaejovis carolinianus. 

The Southern Appalachians and adjacent provinces of the southeastern USA are geologically and biologically diverse, with high levels of endemism. Phylogeographic analyses indicate that animals with small distributions in these regions often contain cryptic diversity and that Pleistocene climate fluctuations had significant impacts on their distributions. We studied the phylogeography of Vaejovis carolinianus (Beauvois), a common forest scorpion from the region, to determine if a more widely distributed animal exhibits similar patterns. Mitochondrial and nuclear DNA, as well as species distribution models, were used to test biogeographic hypotheses. Results indicate that the species is composed of at least nine geographically structured mitochondrial clades. Seven clades are represented by only a few sampling locations, whereas two clades are much larger and appear to be the result of postglacial range expansion in the plateaus and coastal plains adjacent to the Southern Appalachians. A highly disjunct population from Tunica Hills of Louisiana appears to have been isolated since the Pliocene, rejecting a hypothesis of late glacial migration along the Blufflands escarpment. Nuclear DNA is much less structured, perhaps due to differences in habitat and dispersal capabilities between sexes. Although mitochondrial lineages are quite old, mito-nuclear discordance suggests that lineages have not sorted and that V. carolinianus should be treated as a single genetically diverse species.

Graham MR, Garcia EL, Hendrixson BE, Sampognaro AM, Cushing PE. Pliocene origins, Pleistocene refugia, and postglacial range expansions in southern devil scorpions (Vaejovidae: Vaejovis carolinianus). Organisms Diversity & Evolution. 2021;Published online 31. July 2021. [Subscription required for full text]

Family Vaejovidae